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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0708.2749 | Masao Sako | Joshua A. Frieman, B. Bassett, A. Becker, C. Choi, D. Cinabro, F.
DeJongh, D. L. Depoy, B. Dilday, M. Doi, P. M. Garnavich, C. J. Hogan, J.
Holtzman, M. Im, S. Jha, R. Kessler, K. Konishi, H. Lampeitl, J. Marriner, J.
L. Marshall, D. McGinnis, G. Miknaitis, R. C. Nichol, J. L. Prieto, A. G.
Riess, M. W. Richmond, R. Romani, M. Sako, D. P. Schneider, M. Smith, N.
Takanashi, K. Tokita, K. van der Heyden, N. Yasuda, C. Zheng, J.
Adelman-McCarthy, J. Annis, R. J. Assef, J. Barentine, R. Bender, R. D.
Blandford, W. N. Boroski, M. Bremer, H. Brewington, C. A. Collins, A. Crotts,
J. Dembicky, J. Eastman, A. Edge, E. Edmondson, E. Elson, M. E. Eyler, A. V.
Filippenko, R. J. Foley, S. Frank, A. Goobar, T. Gueth, J. E. Gunn, M.
Harvanek, U. Hopp, Y. Ihara, \v{Z}. Ivezi\'c, S. Kahn, J. Kaplan, S. Kent, W.
Ketzeback, S. J. Kleinman, W. Kollatschny, R. G. Kron, J. Krzesi\'nski, D.
Lamenti, G. Leloudas, H. Lin, D. C. Long, J. Lucey, R. H. Lupton, E.
Malanushenko, V. Malanushenko, R. J. McMillan, J. Mendez, C. W. Morgan, T.
Morokuma, A. Nitta, L. Ostman, K. Pan, C. M. Rockosi, A. K. Romer, P.
Ruiz-Lapuente, G. Saurage, K. Schlesinger, S. A. Snedden, J. Sollerman, C.
Stoughton, M. Stritzinger, M. SubbaRao, D. Tucker, P. Vaisanen, L. C. Watson,
S. Watters, J. C. Wheeler, B. Yanny, and D. York | The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary | Submitted to The Astronomical Journal (24 pages, 10 figures) | Astron.J.135:338-347,2008 | 10.1088/0004-6256/135/1/338 | null | astro-ph | null | The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year
project to identify and measure light curves for intermediate-redshift (0.05 <
z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging
over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide
centered on the celestial equator in the Southern Galactic Cap that has been
imaged numerous times in earlier years, enabling construction of a deep
reference image for discovery of new objects. Supernova imaging observations
are being acquired between 1 September and 30 November of 2005-7. During the
first two seasons, each region was imaged on average every five nights.
Spectroscopic follow-up observations to determine supernova type and redshift
are carried out on a large number of telescopes. In its first two three-month
seasons, the survey has discovered and measured light curves for 327
spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c,
32 confirmed SNe II, plus a large number of photometrically identified SNe Ia,
94 of which have host-galaxy spectra taken so far. This paper provides an
overview of the project and briefly describes the observations completed during
the first two seasons of operation.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 01:56:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Frieman",
"Joshua A.",
""
],
[
"Bassett",
"B.",
""
],
[
"Becker",
"A.",
""
],
[
"Choi",
"C.",
""
],
[
"Cinabro",
"D.",
""
],
[
"DeJongh",
"F.",
""
],
[
"Depoy",
"D. L.",
""
],
[
"Dilday",
"B.",
""
],
[
"Doi",
"M.",
""
],
[
"Garnavich",
"P. M.",
""
],
[
"Hogan",
"C. J.",
""
],
[
"Holtzman",
"J.",
""
],
[
"Im",
"M.",
""
],
[
"Jha",
"S.",
""
],
[
"Kessler",
"R.",
""
],
[
"Konishi",
"K.",
""
],
[
"Lampeitl",
"H.",
""
],
[
"Marriner",
"J.",
""
],
[
"Marshall",
"J. L.",
""
],
[
"McGinnis",
"D.",
""
],
[
"Miknaitis",
"G.",
""
],
[
"Nichol",
"R. C.",
""
],
[
"Prieto",
"J. L.",
""
],
[
"Riess",
"A. G.",
""
],
[
"Richmond",
"M. W.",
""
],
[
"Romani",
"R.",
""
],
[
"Sako",
"M.",
""
],
[
"Schneider",
"D. P.",
""
],
[
"Smith",
"M.",
""
],
[
"Takanashi",
"N.",
""
],
[
"Tokita",
"K.",
""
],
[
"van der Heyden",
"K.",
""
],
[
"Yasuda",
"N.",
""
],
[
"Zheng",
"C.",
""
],
[
"Adelman-McCarthy",
"J.",
""
],
[
"Annis",
"J.",
""
],
[
"Assef",
"R. J.",
""
],
[
"Barentine",
"J.",
""
],
[
"Bender",
"R.",
""
],
[
"Blandford",
"R. D.",
""
],
[
"Boroski",
"W. N.",
""
],
[
"Bremer",
"M.",
""
],
[
"Brewington",
"H.",
""
],
[
"Collins",
"C. A.",
""
],
[
"Crotts",
"A.",
""
],
[
"Dembicky",
"J.",
""
],
[
"Eastman",
"J.",
""
],
[
"Edge",
"A.",
""
],
[
"Edmondson",
"E.",
""
],
[
"Elson",
"E.",
""
],
[
"Eyler",
"M. E.",
""
],
[
"Filippenko",
"A. V.",
""
],
[
"Foley",
"R. J.",
""
],
[
"Frank",
"S.",
""
],
[
"Goobar",
"A.",
""
],
[
"Gueth",
"T.",
""
],
[
"Gunn",
"J. E.",
""
],
[
"Harvanek",
"M.",
""
],
[
"Hopp",
"U.",
""
],
[
"Ihara",
"Y.",
""
],
[
"Ivezić",
"Ž.",
""
],
[
"Kahn",
"S.",
""
],
[
"Kaplan",
"J.",
""
],
[
"Kent",
"S.",
""
],
[
"Ketzeback",
"W.",
""
],
[
"Kleinman",
"S. J.",
""
],
[
"Kollatschny",
"W.",
""
],
[
"Kron",
"R. G.",
""
],
[
"Krzesiński",
"J.",
""
],
[
"Lamenti",
"D.",
""
],
[
"Leloudas",
"G.",
""
],
[
"Lin",
"H.",
""
],
[
"Long",
"D. C.",
""
],
[
"Lucey",
"J.",
""
],
[
"Lupton",
"R. H.",
""
],
[
"Malanushenko",
"E.",
""
],
[
"Malanushenko",
"V.",
""
],
[
"McMillan",
"R. J.",
""
],
[
"Mendez",
"J.",
""
],
[
"Morgan",
"C. W.",
""
],
[
"Morokuma",
"T.",
""
],
[
"Nitta",
"A.",
""
],
[
"Ostman",
"L.",
""
],
[
"Pan",
"K.",
""
],
[
"Rockosi",
"C. M.",
""
],
[
"Romer",
"A. K.",
""
],
[
"Ruiz-Lapuente",
"P.",
""
],
[
"Saurage",
"G.",
""
],
[
"Schlesinger",
"K.",
""
],
[
"Snedden",
"S. A.",
""
],
[
"Sollerman",
"J.",
""
],
[
"Stoughton",
"C.",
""
],
[
"Stritzinger",
"M.",
""
],
[
"SubbaRao",
"M.",
""
],
[
"Tucker",
"D.",
""
],
[
"Vaisanen",
"P.",
""
],
[
"Watson",
"L. C.",
""
],
[
"Watters",
"S.",
""
],
[
"Wheeler",
"J. C.",
""
],
[
"Yanny",
"B.",
""
],
[
"York",
"D.",
""
]
] |
0708.2750 | Masao Sako | Masao Sako, B. Bassett, A. Becker, D. Cinabro, F. DeJongh, D. L.
Depoy, B. Dilday, M. Doi, J. A. Frieman, P. M. Garnavich, C. J. Hogan, J.
Holtzman, S. Jha, R. Kessler, K. Konishi, H. Lampeitl, J. Marriner, G.
Miknaitis, R. C. Nichol, J. L. Prieto, A. G. Riess, M. W. Richmond, R.
Romani, D. P. Schneider, M. Smith, M. SubbaRao, N. Takanashi, K. Tokita, K.
van der Heyden, N. Yasuda, C. Zheng, J. Barentine, H. Brewington, C. Choi, J.
Dembicky, M. Harnavek, Y. Ihara, M. Im, W. Ketzeback, S. J. Kleinman, J.
Krzesi\'nski, D. C. Long, E. Malanushenko, V. Malanushenko, R. J. McMillan,
T. Morokuma, A. Nitta, K. Pan, G. Saurage, and S. A. Snedden | The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and
Follow-up Observations | Accepted for publication in The Astronomical Journal (66 pages, 13
figures); typos corrected | Astron.J.135:348-373,2008 | 10.1088/0004-6256/135/1/348 | null | astro-ph | null | The Sloan Digital Sky Survey-II Supernova Survey has identified a large
number of new transient sources in a 300 sq. deg. region along the celestial
equator during its first two seasons of a three-season campaign. Multi-band
(ugriz) light curves were measured for most of the sources, which include solar
system objects, Galactic variable stars, active galactic nuclei, supernovae
(SNe), and other astronomical transients. The imaging survey is augmented by an
extensive spectroscopic follow-up program to identify SNe, measure their
redshifts, and study the physical conditions of the explosions and their
environment through spectroscopic diagnostics. During the survey, light curves
are rapidly evaluated to provide an initial photometric type of the SNe, and a
selected sample of sources are targeted for spectroscopic observations. In the
first two seasons, 476 sources were selected for spectroscopic observations, of
which 403 were identified as SNe. For the Type Ia SNe, the main driver for the
Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the
photometric SN Ia candidates were spectroscopically classified as non-SN Ia
instead, and the remaining 4% resulted in low signal-to-noise, unclassified
spectra. This paper describes the search algorithm and the software, and the
real-time processing of the SDSS imaging data. We also present the details of
the supernova candidate selection procedures and strategies for follow-up
spectroscopic and imaging observations of the discovered sources.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 02:04:59 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Oct 2007 16:10:41 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sako",
"Masao",
""
],
[
"Bassett",
"B.",
""
],
[
"Becker",
"A.",
""
],
[
"Cinabro",
"D.",
""
],
[
"DeJongh",
"F.",
""
],
[
"Depoy",
"D. L.",
""
],
[
"Dilday",
"B.",
""
],
[
"Doi",
"M.",
""
],
[
"Frieman",
"J. A.",
""
],
[
"Garnavich",
"P. M.",
""
],
[
"Hogan",
"C. J.",
""
],
[
"Holtzman",
"J.",
""
],
[
"Jha",
"S.",
""
],
[
"Kessler",
"R.",
""
],
[
"Konishi",
"K.",
""
],
[
"Lampeitl",
"H.",
""
],
[
"Marriner",
"J.",
""
],
[
"Miknaitis",
"G.",
""
],
[
"Nichol",
"R. C.",
""
],
[
"Prieto",
"J. L.",
""
],
[
"Riess",
"A. G.",
""
],
[
"Richmond",
"M. W.",
""
],
[
"Romani",
"R.",
""
],
[
"Schneider",
"D. P.",
""
],
[
"Smith",
"M.",
""
],
[
"SubbaRao",
"M.",
""
],
[
"Takanashi",
"N.",
""
],
[
"Tokita",
"K.",
""
],
[
"van der Heyden",
"K.",
""
],
[
"Yasuda",
"N.",
""
],
[
"Zheng",
"C.",
""
],
[
"Barentine",
"J.",
""
],
[
"Brewington",
"H.",
""
],
[
"Choi",
"C.",
""
],
[
"Dembicky",
"J.",
""
],
[
"Harnavek",
"M.",
""
],
[
"Ihara",
"Y.",
""
],
[
"Im",
"M.",
""
],
[
"Ketzeback",
"W.",
""
],
[
"Kleinman",
"S. J.",
""
],
[
"Krzesiński",
"J.",
""
],
[
"Long",
"D. C.",
""
],
[
"Malanushenko",
"E.",
""
],
[
"Malanushenko",
"V.",
""
],
[
"McMillan",
"R. J.",
""
],
[
"Morokuma",
"T.",
""
],
[
"Nitta",
"A.",
""
],
[
"Pan",
"K.",
""
],
[
"Saurage",
"G.",
""
],
[
"Snedden",
"S. A.",
""
]
] |
0708.2751 | Zvi Ovadyahu | D. Kowal and Z. Ovadyahu | Scale dependent superconductor-insulator transition | Contribution to the proceedings of "Fluctuations and phase
transitions in superconductors", Nazareth Ilit, Israel, June 10-14, 2007 | null | 10.1016/j.physc.2007.07.012 | null | cond-mat.dis-nn cond-mat.supr-con | null | We study the disorder driven superconductor to insulator transition in
amorphous films of high carrier-concentration indium-oxide. Using thin films
with various sizes and aspect ratios we show that the `critical'
sheet-resistance $R_{{\small \square}}$ depends systematically on sample
geometry; superconductivity disappears when $R_{{\small \square}}$ exceeds
$\approx6 $k$\Omega$ in large samples. On the other hand, wide and sufficiently
short samples of the same batch exhibit superconductivity (judged by
conductivity versus temperature) up to $R_{{\small \square}}$ which is
considerably larger. These results support the inhomogeneous scenario for the
superconductor-insulator transition.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 02:18:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kowal",
"D.",
""
],
[
"Ovadyahu",
"Z.",
""
]
] |
0708.2752 | Ronald van Luijk | Ronald van Luijk | Cubic points on cubic curves and the Brauer-Manin obstruction on K3
surfaces | 17 pages, comments welcome | null | null | null | math.NT math.AG | null | We show that if over some number field there exists a certain diagonal plane
cubic curve that is locally solvable everywhere, but that does not have points
over any cubic galois extension of the number field, then the algebraic part of
the Brauer-Manin obstruction is not the only obstruction to the Hasse principle
for K3 surfaces.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 02:27:13 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"van Luijk",
"Ronald",
""
]
] |
0708.2753 | Sarah Morrison | S. Morrison and A. S. Parkins | Dynamical quantum phase transitions in the dissipative
Lipkin-Meshkov-Glick model and proposed realization in optical cavity QED | 4 pages, 4 figures, typos corrected and other minor changes | Phys. Rev. Lett. 100, 040403 (2008) | 10.1103/PhysRevLett.100.040403 | null | quant-ph cond-mat.other | null | We present an optical cavity QED configuration that is described by a
dissipative version of the Lipkin-Meshkov-Glick model of an infinitely
coordinated spin system. This open quantum system exhibits both first- and
second-order non-equilibrium quantum phase transitions as a single, effective
field parameter is varied. Light emitted from the cavity offers measurable
signatures of the critical behavior, including that of the spin-spin
entanglement.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 02:56:38 GMT"
},
{
"version": "v2",
"created": "Fri, 1 Feb 2008 04:17:10 GMT"
}
] | 2008-02-01T00:00:00 | [
[
"Morrison",
"S.",
""
],
[
"Parkins",
"A. S.",
""
]
] |
0708.2754 | Bernard Shiffman | Bernard Shiffman | Convergence of random zeros on complex manifolds | 16 pages | Sci. China Ser. A (Special issue for Qikeng Lu) 51 (2008), 707-720 | 10.1007/s11425-008-0060-9 | null | math.CV math.AG math.PR | null | We show that the zeros of random sequences of Gaussian systems of polynomials
of increasing degree almost surely converge to the expected limit distribution
under very general hypotheses. In particular, the normalized distribution of
zeros of systems of m polynomials of degree N, orthonormalized on a regular
compact subset K of C^m, almost surely converge to the equilibrium measure on K
as the degree N goes to infinity.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 03:19:02 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Shiffman",
"Bernard",
""
]
] |
0708.2755 | Seung Woo Ham | S.W. Ham (1), S.H. Kim (2), S.K. OH (1,2), and D. Son (1) | Higgs bosons of the NMSSM with explicit CP violation at the ILC | 36 pages, 18 figures | Phys.Rev.D76:115013,2007 | 10.1103/PhysRevD.76.115013 | null | hep-ph | null | We study the Higgs sector of the next-to-minimal supersymmetric standard
model (NMSSM) with explicit CP violation at the one-loop level, where the
radiative corrections due to the quarks and squarks of the third generation are
taken into account. We expect that, within a reasonable region of the parameter
space of the present model, at least one of five neutral Higgs bosons may be
produced at the future $e^+ e^-$ International Linear Collider (ILC) with
$\sqrt{s} = 500$ GeV, with cross section larger than 12 fb, 15 fb, and 1.5 fb,
respectively, via the Higgs-strahlung process, the $WW$ fusion process, and the
$ZZ$ fusion process. We find that the effect of the CP phase in the present
model yields significant influences upon the production cross sections of the
five neutral Higgs bosons. We also study the decay modes of the five neutral
Higgs bosons to find that their decay widths are similarly affected by the CP
phase. Some of the decay modes in the present model behave differently from
those of the Standard Model.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 03:37:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ham",
"S. W.",
""
],
[
"Kim",
"S. H.",
""
],
[
"OH",
"S. K.",
""
],
[
"Son",
"D.",
""
]
] |
0708.2756 | Marjorie E. Gonzalez | M. E. Gonzalez (1), R. Dib (1), V. M. Kaspi (1), P. M. Woods (2), C.
R. Tam (1), F. P. Gavriil (3) ((1) McGill University, (2) Dynetics, Inc.;
NSSTC, (3) NASA GSFC) | Long-term X-ray changes in the emission from the anomalous X-ray pulsar
4U 0142+61 | 10 pages, 9 figures, in emulateapj style. Submitted to ApJ | Astrophys.J.716:1345-1355,2010 | 10.1088/0004-637X/716/2/1345 | null | astro-ph | null | We present results obtained from X-ray observations of the anomalous X-ray
pulsar (AXP) 4U 0142+61 taken between 2000-2007 using XMM-Newton, Chandra and
Swift. In observations taken before 2006, the pulse profile is observed to
become more sinusoidal and the pulsed fraction increased with time. These
results confirm those derived using the Rossi X-ray Timing Explorer and expand
the observed evolution to energies below 2 keV. The XMM-Newton total flux in
the 0.5-10 keV band is observed to be nearly constant in observations taken
before 2006, while an increase of ~10% is seen afterwards and coincides with
the burst activity detected from the source in 2006-2007. After these bursts,
the evolution towards more sinusoidal pulse profiles ceased while the pulsed
fraction showed a further increase. No evidence for large-scale, long-term
changes in the emission as a result of the bursts is seen. The data also
suggest a correlation between the flux and hardness of the spectrum, with
brighter observations on average having a harder spectrum. As pointed out by
other authors, we find that the standard blackbody plus power-law model does
not provide the best spectral fit to the emission from 4U 0142+61. We also
report on observations taken with the Gemini telescope after two bursts. These
observations show source magnitudes consistent with previous measurements. Our
results demonstrate the wide range of X-ray variability characteristics seen in
AXPs and we discuss them in light of current emission models for these sources.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:24:18 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Aug 2007 21:03:43 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Gonzalez",
"M. E.",
""
],
[
"Dib",
"R.",
""
],
[
"Kaspi",
"V. M.",
""
],
[
"Woods",
"P. M.",
""
],
[
"Tam",
"C. R.",
""
],
[
"Gavriil",
"F. P.",
""
]
] |
0708.2757 | Alexei Davydov | Alexei Davydov | Twisted automorphisms of Hopf algebras | null | null | null | null | math.QA math.CT | null | Twisted homomorphisms of bialgebras are bialgebra homomorphisms from the
first into Drinfeld twistings of the second. They possess a composition
operation extending composition of bialgebra homomorphisms. Gauge
transformations of twists, compatible with adjacent homomorphisms, give rise to
gauge transformation of twisted homomorphisms, which behave nicely with respect
to compositions. Here we study (gauge classes of) twisted automorphisms of
cocommutative Hopf algebras. After revising well-known relations between
twists, twisted forms of bialgebras and $R$-matrices (for commutative
bialgebras) we describe twisted automorphisms of universal enveloping algebras.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:05:47 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Davydov",
"Alexei",
""
]
] |
0708.2758 | Alexei Davydov | Alexei Davydov | Twisted automorphisms of group algebras | null | null | null | null | math.RT math.QA | null | We continue the study of twisted automorphisms of Hopf algebras started in
"Twisted automorphisms of Hopf algebras". In this paper we concentrate on the
group algebra case. We describe the group of twisted automorphisms of the group
algebra of a group of order coprime to 6. The description turns out to be very
similar to the one for the universal enveloping algebra given in "Twisted
automorphisms of Hopf algebras".
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:17:09 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Davydov",
"Alexei",
""
]
] |
0708.2759 | Chitra Nayak R | Chitra R Nayak, V. C. Kuriakose | Phase effects on synchronization by dynamical relaying in delay-coupled
systems | 14 pages, 8 figures, Accepted for publication in "CHAOS" | null | null | null | nlin.CD | null | Synchronization in an array of mutually coupled systems with a finite
time-delay in coupling is studied using Josephson junction as a model system.
The sum of the transverse Lyapunov exponents is evaluated as a function of the
parameters by linearizing the equation about the synchronization manifold. The
dependence of synchronization on damping parameter, coupling constant and
time-delay is studied numerically. The change in the dynamics of the system due
to time-delay and phase difference between the applied fields is studied. The
case where a small frequency detuning between the applied fields is also
discussed.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:26:24 GMT"
},
{
"version": "v2",
"created": "Thu, 1 Nov 2007 05:05:59 GMT"
},
{
"version": "v3",
"created": "Fri, 28 Mar 2008 07:04:09 GMT"
},
{
"version": "v4",
"created": "Thu, 22 May 2008 09:34:11 GMT"
}
] | 2008-05-22T00:00:00 | [
[
"Nayak",
"Chitra R",
""
],
[
"Kuriakose",
"V. C.",
""
]
] |
0708.2760 | Qing-Guo Huang | Qing-Guo Huang | Theoretic Limits on the Equation of State Parameter of Quintessence | 4 pages, 2 figures; minor corrections and refs added | Phys.Rev.D77:103518,2008 | 10.1103/PhysRevD.77.103518 | null | astro-ph hep-ph hep-th | null | The value of scalar field coupled to gravity should be less than the Planck
scale in the consistent theory of quantum gravity. It provides a theoretic
constraint on the equation of state parameter for the quintessence. In some
cases our theoretic constraints are more stringent than the constraints from
the present experiments.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:29:55 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Sep 2007 12:31:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Huang",
"Qing-Guo",
""
]
] |
0708.2761 | Alexei Davydov | Alexei Davydov | Nuclei of categories with tensor products | null | null | null | null | math.CT | null | Following the analogy between algebras (monoids) and monoidal categories the
construction of nucleus for non-associative algebras is simulated on the
categorical level. Nuclei of categories of modules are considered as an
example.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 04:56:23 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Davydov",
"Alexei",
""
]
] |
0708.2762 | Matt Dobbs | Matt Dobbs, Eric Bissonnette, and Helmuth Spieler | Digital Frequency Domain Multiplexer for mm-Wavelength Telescopes | 6 pages, 6 figures, Submitted May 2007 to IEEE Transactions on
Nuclear Science (TNS) | IEEE Trans.Nucl.Sci.55:21-26,2008 | 10.1109/TNS.2007.911601 | null | physics.ins-det | null | An FPGA based digital signal processing (DSP) system for biasing and reading
out multiplexed bolometric detectors for mm-wavelength telescopes is presented.
This readout system is being deployed for balloon-borne and ground based
cosmology experiments with the primary goal of measuring the signature of
inflation with the Cosmic Microwave Background Radiation. The system consists
of analog superconducting electronics running at 250mK and 4K, coupled to
digital room temperature backend electronics described here. The digital
electronics perform the real time functionality with DSP algorithms implemented
in firmware. A soft embedded processor provides all of the slow housekeeping
control and communications. Each board in the system synthesizes
multi-frequency combs of 8 to 32 carriers in the MHz band to bias the
detectors. After the carriers have been modulated with the sky-signal by the
detectors, the same boards digitize the comb directly. The carriers are mixed
down to base-band and low pass filtered. The signal bandwidth of 0.050 Hz - 100
Hz places extreme requirements on stability and requires powerful filtering
techniques to recover the sky-signal from the MHz carriers.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 05:01:25 GMT"
}
] | 2009-05-13T00:00:00 | [
[
"Dobbs",
"Matt",
""
],
[
"Bissonnette",
"Eric",
""
],
[
"Spieler",
"Helmuth",
""
]
] |
0708.2763 | Nayantara Gupta | Nayantara Gupta (UNLV), Bing Zhang (UNLV) | Diagnosing GRB Prompt Emission Site with Spectral Cut-Off Energy | 6 pages,2 figures version to be published in MNRAS Letters | MNRAS Lett 384 (2008) L11-L15 | 10.1111/j.1745-3933.2007.00411.x | null | astro-ph | null | The site and mechanism of gamma-ray burst (GRB) prompt emission is still
unknown. Although internal shocks have been widely discussed as the emission
site of GRBs, evidence supporting other emission sites have been also suggested
recently, including the closer-in photosphere where the fireball becomes
transparent and further-out radii near the fireball deceleration radius where
magnetic dissipation may be important. With the successful operation of the
GLAST experiment, prompt high energy emission spectra from many GRBs would be
detected in the near future. We suggest that the cut-off energy of the prompt
emission spectrum from a GRB depends on both the fireball bulk Lorentz factor
and the unknown emission radius from the central engine. If the bulk Lorentz
factor could be independently measured (e.g. from early afterglow
observations), the observed spectral cutoff energy can be used to diagnose the
emission site of gamma-rays. This would provide valuable information to
understand the physical origin of the GRB promp emission.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 05:04:23 GMT"
},
{
"version": "v2",
"created": "Mon, 15 Oct 2007 18:29:42 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Gupta",
"Nayantara",
"",
"UNLV"
],
[
"Zhang",
"Bing",
"",
"UNLV"
]
] |
0708.2764 | Hock Peng Chan | Hock Peng Chan | Maxima of Moving Sums in a Poisson Random Field | null | null | null | null | math.PR | null | The extremal tail probabilities of moving sums in a marked Poisson random
field is examined here. These sums are computed by adding up the weighted
occurrences of events lying within a scanning set of fixed shape and size.
Change of measure and analysis of local random fields are used to provide tail
probabilities. The asymptotic constants are initially expressed in a form that
seems hard to evaluate and do not seem to provide any additional information on
the properties of the constants. A more sophisticated approach is then
undertaken giving rise to an expression that is not only neater but also able
to provide computable bounds. The technique used to obtain this constant can
also be modified to work on continuous processes.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 05:52:16 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Chan",
"Hock Peng",
""
]
] |
0708.2765 | Hisatoshi Yokoyama | Hisatoshi Yokoyama and Masao Ogata | Doublon-Holon Binding Effects on Mott Transitions in Two-Dimensional
Bose Hubbard Model | 5 pages, 6 figures, proceedings of SNS2007 | null | 10.1016/j.jpcs.2008.06.087 | null | cond-mat.str-el cond-mat.stat-mech | null | A mechanism of Mott transitions in a Bose Hubbard model on a square lattice
is studied, using a variational Monte Carlo method. Besides an onsite
correlation factor, we introduce a four-body doublon-holon factor into the
trial state, which considerably improves the variational energy and can
appropriately describe a superfluid-insulator transition. Its essense consists
in binding (and unbinding) of a doublon to a holon in a finite short range,
identical with the cases of fermions. The features of this transition are
qualitatively different from those of Brinkman-Rice-type transitions.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 06:44:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Yokoyama",
"Hisatoshi",
""
],
[
"Ogata",
"Masao",
""
]
] |
0708.2766 | Nobuyuki Motoyui | Nobuyuki Motoyui and Mitsuru Yamada | Operator ordering in Two-dimensional N=1 supersymmetry with curved
manifold | 7 pages | Mod.Phys.Lett.A22:1797-1803,2007 | 10.1142/S0217732307023912 | IU-MSTP/74 | hep-th | null | We investigate an operator ordering problem in two-dimensional N=1
supersymmetric model which consists of n real superfields. There arises an
operator ordering problem when the target space is curved. We have to fix the
ordering in quantum operator properly to obtain the correct supersymmetry
algebra. We demonstrate that the super-Poincar\'{e} algebra fixes the correct
operator ordering. We obtain a supercurrent with correct operator ordering and
a central extension of supersymmetry algebra.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 06:58:54 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Motoyui",
"Nobuyuki",
""
],
[
"Yamada",
"Mitsuru",
""
]
] |
0708.2767 | Xavier Calmet | Xavier Calmet | Equivalence Principle and the Gauge Hierarchy Problem | 9 pages | Phys.Rev.D77:047502,2008 | 10.1103/PhysRevD.77.047502 | null | hep-ph hep-th | null | We show that the gauge hierarchy problem can be solved in the framework of
scalar-tensor theories of gravity very much in the same way as it is solved in
the Randall-Sundrum scenario. Our solution involves a fine-tuning of the
gravitational sector. However our mechanism does not require the introduction
of extra-dimensions or new physics strongly coupled to the standard model in
the low energy regime. We do introduce a new scalar field which is however
coupled only gravitationally to regular matter. The physical reason for the
splitting between the weak scale and the Planck scale is a violation of the
Einstein's equivalence principle.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 07:30:30 GMT"
},
{
"version": "v2",
"created": "Tue, 25 Sep 2007 18:43:25 GMT"
},
{
"version": "v3",
"created": "Wed, 19 Mar 2008 17:49:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Calmet",
"Xavier",
""
]
] |
0708.2768 | C. Boehm | Celine Boehm, Joseph Silk | A new test of the light dark matter hypothesis | 3 pages, 1 figure | Phys.Lett.B661:287-289,2008 | 10.1016/j.physletb.2008.02.019 | null | hep-ph | null | Detection of a surprisingly high flux of positron annihilation radiation from
the inner galaxy has motivated the proposal that dark matter is made of weakly
interacting light particles (possibly as light as the electron). This scenario
is extremely hard to test in current high energy physics experiments. Here,
however, we demonstrate that the current value of the electron anomalous
magnetic moment already has the required precision to unambiguously test the
light dark matter hypothesis. If confirmed, the implications for astrophysics
are far-reaching.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 07:39:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Boehm",
"Celine",
""
],
[
"Silk",
"Joseph",
""
]
] |
0708.2769 | David Pierce | David Pierce | Fields with several commuting derivations | 18 pages | null | null | null | math.LO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For every natural number $m$, the existentially closed models of the theory
of fields with $m$ commuting derivations can be given a first-order geometric
characterization in several ways. In particular, the theory of these
differential fields has a model-companion. The axioms are that certain
differential varieties determined by certain ordinary varieties are nonempty.
There is no restriction on the characteristic of the underlying field.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 07:39:42 GMT"
},
{
"version": "v2",
"created": "Thu, 3 Jan 2013 09:39:28 GMT"
}
] | 2013-01-04T00:00:00 | [
[
"Pierce",
"David",
""
]
] |
0708.2770 | Peter B. Gilkey | M. Brozos-Vazquez, E. Garcia-Rio, P. Gilkey, and R. Vazquez-Lorenzo | Examples of signature (2,2) manifolds with commuting curvature operators | null | null | 10.1088/1751-8113/40/43/021 | null | math.DG | null | We exhibit Walker manifolds of signature (2,2) with various commutativity
properties for the Ricci operator, the skew-symmetric curvature operator, and
the Jacobi operator. If the Walker metric is a Riemannian extension of an
underlying affine structure A, these properties are related to the Ricci tensor
of A.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 07:47:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Brozos-Vazquez",
"M.",
""
],
[
"Garcia-Rio",
"E.",
""
],
[
"Gilkey",
"P.",
""
],
[
"Vazquez-Lorenzo",
"R.",
""
]
] |
0708.2771 | Tatiana Hessami Pilehrood | Kh. Hessami Pilehrood, T. Hessami Pilehrood | Approximations to Euler's constant | 11 pages | Math. Inequal. Appl. 13 (2010), no. 4, 761--773 | null | null | math.NT | null | We study a problem of finding good approximations to Euler's constant
$\gamma=\lim_{n\to\infty}S_n,$ where $S_n=\sum_{k=1}^n\frac{1}{n}-\log(n+1),$
by linear forms in logarithms and harmonic numbers. In 1995, C. Elsner showed
that slow convergence of the sequence $S_n$ can be significantly improved if
$S_n$ is replaced by linear combinations of $S_n$ with integer coefficients. In
this paper, considering more general linear transformations of the sequence
$S_n$ we establish new accelerating convergence formulae for $\gamma.$ Our
estimates sharpen and generalize recent Elsner's, Rivoal's and author's
results.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:09:04 GMT"
}
] | 2012-10-09T00:00:00 | [
[
"Pilehrood",
"Kh. Hessami",
""
],
[
"Pilehrood",
"T. Hessami",
""
]
] |
0708.2772 | Tolga Etgu | Tolga Etg\"u, Burak Ozbagci | On the contact Ozsvath-Szabo invariant | 17 pages, 18 figures | Studia Sci. Math. Hungar. 47 (2010), no. 1, 90--107 | null | null | math.GT math.SG | null | Sarkar and Wang proved that the hat version of Heegaard Floer homology group
of a closed oriented 3-manifold is combinatorial starting from an arbitrary
nice Heegaard diagram and in fact every closed oriented 3-manifold admits such
a Heegaard diagram. Plamenevskaya showed that the contact Ozsvath-Szabo
invariant is combinatorial once we are given an open book decomposition
compatible with a contact structure. The idea is to combine the algorithm of
Sarkar and Wang with the recent description of the contact Ozsvath-Szabo
invariant due to Honda, Kazez and Matic. Here we simply observe that the hat
version of the Heegaard Floer homology group and the contact Ozsvath-Szabo
invariant in this group can be combinatorially calculated starting from a
contact surgery diagram. We give detailed examples pointing out to some
shortcuts in the computations.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:06:38 GMT"
}
] | 2012-06-13T00:00:00 | [
[
"Etgü",
"Tolga",
""
],
[
"Ozbagci",
"Burak",
""
]
] |
0708.2773 | Norbert Poncin | Mourad Ammar, Guy Kass, Mohsen Masmoudi, Norbert Poncin | Strongly r-matrix induced tensors, Koszul cohomology, and
arbitrary-dimensional quadratic Poisson cohomology | 25 pages | null | null | null | math.SG | null | We introduce the concept of strongly $r$-matrix induced ({\small SRMI})
Poisson structure, report on the relation of this property with the stabilizer
dimension of the considered quadratic Poisson tensor, and classify the Poisson
structures of the Dufour-Haraki classification (DHC) according to their
membership of the family of {\small SRMI} tensors. One of the main results of
our work is a generic cohomological procedure for {\small SRMI} Poisson
structures in arbitrary dimension. This approach allows decomposing Poisson
cohomology into, basically, a Koszul cohomology and a relative cohomology.
Moreover, we investigate this associated Koszul cohomology, highlight its tight
connections with Spectral Theory, and reduce the computation of this main
building block of Poisson cohomology to a problem of linear algebra. We apply
these upshots to two structures of the DHC and provide an exhaustive
description of their cohomology. We thus complete our list of data obtained in
previous works, see \cite{MP} and \cite{AMPN}, and gain fairly good insight
into the structure of Poisson cohomology.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:11:43 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Ammar",
"Mourad",
""
],
[
"Kass",
"Guy",
""
],
[
"Masmoudi",
"Mohsen",
""
],
[
"Poncin",
"Norbert",
""
]
] |
0708.2774 | Frederique Motte | Fr\'ed\'erique Motte (AIME), S. Bontemps (OASU, L3AB), P. Schilke
(MPIfR), N. Schneider (AIME), K. M. Menten (MPIfR), D. Brogui\`ere (IRAM) | The earliest phases of high-mass star formation: a 3 square degree
millimeter continuum mapping of Cygnus X | 32 pages, 62 figures to be published in Astronomy & Astrophysics
journal | Astronomy and Astrophysics 476 (2007) 1243-1260 | 10.1051/0004-6361:20077843 | null | astro-ph | null | We have made an extensive 1.2mm continuum mosaicing study of the Cygnus X
molecular cloud complex using the MAMBO cameras at the IRAM 30 m telescope. We
then compared our mm maps with mid-IR images, and have made SiO(2-1) follow-up
observations of the best candidate progenitors of high-mass stars. Our complete
study of Cygnus X provides, for the first time, an unbiased census of massive
young stellar objects. We discover 129 massive dense cores, among which 42 are
probable precursors of high-mass stars. Our study qualifies 17 cores as good
candidates for hosting massive IR-quiet protostars, while up to 25 cores
potentially host high-luminosity IR protostars. We fail to discover the
high-mass analogs of pre-stellar dense cores in CygnusX, but find several
massive starless clumps that might be gravitationally bound. Since our sample
is derived from a single molecular complex and covers every embedded phase of
high-mass star formation, it gives the first statistical estimates of their
lifetime. In contrast to what is found for low-mass class 0 and class I phases,
the IR-quiet protostellar phase of high-mass stars may last as long as their
better-known high-luminosity IR phase. The statistical lifetimes of high-mass
protostars and pre-stellar cores (~ 3 x 10^4 yr and < 10^3 yr) in Cygnus X are
one and two order(s) of magnitude smaller, respectively, than what is found in
nearby, low-mass star-forming regions. We therefore propose that high-mass
pre-stellar and protostellar cores are in a highly dynamic state, as expected
in a molecular cloud where turbulent processes dominate.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:24:37 GMT"
}
] | 2008-01-10T00:00:00 | [
[
"Motte",
"Frédérique",
"",
"AIME"
],
[
"Bontemps",
"S.",
"",
"OASU, L3AB"
],
[
"Schilke",
"P.",
"",
"MPIfR"
],
[
"Schneider",
"N.",
"",
"AIME"
],
[
"Menten",
"K. M.",
"",
"MPIfR"
],
[
"Broguière",
"D.",
"",
"IRAM"
]
] |
0708.2775 | Artemov Andrey | A. N. Artemov | Coupled layered superconductor as a system of 2D Coulomb particles of
two kinds | 11 pages, 4 figures | null | null | null | cond-mat.supr-con | null | It is shown that the Josephson subsystem of the Lawrence-Doniach model of
layered superconductors in the London approximation can be presented as a
system with variable number of classical Coulomb particles. This allows us to
consider the vortex system of a coupled layered superconductor as the system of
these particles and 2D-vortices interacting with each other. The grand
partition function of the system was written and transformed into the form of
field one. Thermodynamical properties of the model obtained was studied. It is
found that there is no a phase transition in the system. Instead of this the
model demonstrates the crossover from a low temperature 3D behavior to high
temperature 2D one which can look as a phase transition for experimental
purposes.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:26:58 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Nov 2007 08:17:43 GMT"
}
] | 2007-11-08T00:00:00 | [
[
"Artemov",
"A. N.",
""
]
] |
0708.2776 | Daniel Cranston | Daniel W. Cranston | Antimagic labelings of regular bipartite graphs: An application of the
Marriage Theorem | 9 pages | Journal of Graph Theory. Vol. 60, March 2009, pp. 173-182 | null | null | math.CO | null | A labeling of a graph is a bijection from $E(G)$ to the set $\{1, 2,...,
|E(G)|\}$. A labeling is \textit{antimagic} if for any distinct vertices $u$
and $v$, the sum of the labels on edges incident to $u$ is different from the
sum of the labels on edges incident to $v$. We say a graph is antimagic if it
has an antimagic labeling. In 1990, Ringel conjectured that every connected
graph other than $K_2$ is antimagic. In this paper, we show that every regular
bipartite graph (with degree at least 2) is antimagic. Our technique relies
heavily on the Marriage Theorem.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:31:27 GMT"
}
] | 2011-10-12T00:00:00 | [
[
"Cranston",
"Daniel W.",
""
]
] |
0708.2777 | Dominic Schuhmacher | Dominic Schuhmacher and Aihua Xia | A new metric between distributions of point processes | 20 pages, 2 figures | null | null | null | math.PR math.ST stat.TH | null | Most metrics between finite point measures currently used in the literature
have the flaw that they do not treat differing total masses in an adequate
manner for applications. This paper introduces a new metric $\bar{d}_1$ that
combines positional differences of points under a closest match with the
relative difference in total mass in a way that fixes this flaw. A
comprehensive collection of theoretical results about $\bar{d}_1$ and its
induced Wasserstein metric $\bar{d}_2$ for point process distributions are
given, including examples of useful $\bar{d}_1$-Lipschitz continuous functions,
$\bar{d}_2$ upper bounds for Poisson process approximation, and $\bar{d}_2$
upper and lower bounds between distributions of point processes of i.i.d.
points. Furthermore, we present a statistical test for multiple point pattern
data that demonstrates the potential of $\bar{d}_1$ in applications.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:43:54 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Schuhmacher",
"Dominic",
""
],
[
"Xia",
"Aihua",
""
]
] |
0708.2778 | Paula Stella Teixeira | Paula S. Teixeira (1,2,3), Luis A. Zapata (4), and Charles J. Lada (1)
((1) Harvard-Smithsonian Center for Astrophysics, Cambridge MA, USA, (2)
Faculdade de Ciencias da Universidade de Lisboa, Lisbon, Portugal, (3)
Laboratorio Associado Instituto D. Luiz - SIM, Universidade de Lisboa,
Lisbon, Portugal, (4) Max-Planck-Institut fur Radioastronomie, Bonn, Germany) | A dense micro-cluster of Class 0 protostars in NGC 2264 D-MM1 | Accepted for publication in the Astrophysical Journal Letters | null | 10.1086/522494 | null | astro-ph | null | We present sensitive and high angular resolution (~1") 1.3 mm continuum
observations of the dusty core D-MM1 in the Spokes cluster in NGC 2264 using
the Submillimeter Array. A dense micro-cluster of seven Class 0 sources was
detected in a 20" x 20" region with masses between 0.4 to 1.2 solar masses and
deconvolved sizes of about 600 AU. We interpret the 1.3 mm emission as arising
from the envelopes of the Class 0 protostellar sources. The mean separation of
the 11 known sources (SMA Class 0 and previously known infrared sources) within
D-MM1 is considerably smaller than the characteristic spacing between sources
in the larger Spokes cluster and is consistent with hierarchical thermal
fragmentation of the dense molecular gas in this region.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:51:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Teixeira",
"Paula S.",
""
],
[
"Zapata",
"Luis A.",
""
],
[
"Lada",
"Charles J.",
""
]
] |
0708.2779 | Valerio Cappellini Dr. | Valerio Cappellini (1 and 2) ((1) "Mark Kac" Complex Systems Research
Centre, Uniwersytet Jagiellonski, Krakow, Poland, (2) Centrum Fizyki
Teoretycznej, Polska Akademia Nauk, Warszawa, Poland) | A Survey on the Classical Limit of Quantum Dynamical Entropies | LaTeX, 21 pages, Presented at the 3rd Workshop on Quantum Chaos and
Localization Phenomena, Warsaw, Poland, May 25-27, 2007 | Acta Phys. Polon. A 112(4), 589-605 (2007) | null | null | math-ph math.DS math.MP quant-ph | null | We analyze the behavior of quantum dynamical entropies production from
sequences of quantum approximants approaching their (chaotic) classical limit.
The model of the quantized hyperbolic automorphisms of the 2-torus is examined
in detail and a semi-classical analysis is performed on it using coherent
states, fulfilling an appropriate dynamical localization property.
Correspondence between quantum dynamical entropies and the Kolmogorov-Sinai
invariant is found only over time scales that are logarithmic in the
quantization parameter.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:36:22 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 18:09:54 GMT"
}
] | 2007-12-13T00:00:00 | [
[
"Cappellini",
"Valerio",
"",
"1 and 2"
]
] |
0708.2780 | Andrea Macchi | Andrea Macchi, Alessandra Bigongiari, Francesco Ceccherini, Fulvio
Cornolti, Tatiana V. Liseikina, Marco Borghesi, Satyabrata Kar, Lorenzo
Romaganani | Ion dynamics and coherent structure formation following laser pulse
self-channeling | 10 pages, 5 figures (visit http://www.df.unipi.it/~macchi to download
a high-resolution version), to appear in Plasma Physics and Controlled Fusion
(Dec. 2007), special issue containing invited papers from the 34th EPS
Conference on Plasma Physics (Warsaw, July 2007) | null | 10.1088/0741-3335/49/12B/S05 | null | physics.plasm-ph | null | The propagation of a superintense laser pulse in an underdense, inhomogeneous
plasma has been studied numerically by two-dimensional particle-in-cell
simulations on a time scale extending up to several picoseconds. The effects of
the ion dynamics following the charge-displacement self-channeling of the laser
pulse have been addressed. Radial ion acceleration leads to the ``breaking'' of
the plasma channel walls, causing an inversion of the radial space-charge field
and the filamentation of the laser pulse. At later times a number of
long-lived, quasi-periodic field structures are observed and their dynamics is
characterized with high resolution. Inside the plasma channel, a pattern of
electric and magnetic fields resembling both soliton- and vortex-like
structures is observed.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:51:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Macchi",
"Andrea",
""
],
[
"Bigongiari",
"Alessandra",
""
],
[
"Ceccherini",
"Francesco",
""
],
[
"Cornolti",
"Fulvio",
""
],
[
"Liseikina",
"Tatiana V.",
""
],
[
"Borghesi",
"Marco",
""
],
[
"Kar",
"Satyabrata",
""
],
[
"Romaganani",
"Lorenzo",
""
]
] |
0708.2781 | V. A. Kuz'menko | V.A. Kuz'menko | Comment on "Entropy production and the arrow of time" | 1 page | null | null | null | physics.gen-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | J.M.R. Parrondo at al. in arXiv:0904.1573 continue numerous efforts to unify
the concepts of the arrow of time and entropy production with the concept of
time invariance in physics. This is a wrong way.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:54:18 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Mar 2009 07:12:43 GMT"
},
{
"version": "v3",
"created": "Wed, 13 May 2009 09:23:18 GMT"
},
{
"version": "v4",
"created": "Fri, 19 Jun 2009 07:14:39 GMT"
},
{
"version": "v5",
"created": "Sun, 26 Jul 2009 09:33:14 GMT"
}
] | 2009-07-27T00:00:00 | [
[
"Kuz'menko",
"V. A.",
""
]
] |
0708.2782 | Johan Chang | J. Chang, M. Shi, S. Pailhes, M. Maansson, T. Claesson, O. Tjernberg,
A. Bendounan, Y. Sassa, L. Patthey, N. Momono, M. Oda, M. Ido, S. Guerrero C.
Mudry and J. Mesot | Anisotropic quasiparticle scattering rates in slightly underdoped to
optimally doped high-temperature \LSCO\ superconductors | Final version published in PRB | Phys. Rev. B 78, 205103 (2008) | 10.1103/PhysRevB.78.205103 | null | cond-mat.supr-con | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An angle-resolved photoemission study of the scattering rate in the
superconducting phase of the high-temperature superconductor \LSCO\ with
$x=0.145$ and $x=0.17$, as a function of binding energy and momentum, is
presented. We observe that the scattering rate scales linearly with binding
energy up to the high-energy scale $E_1\sim0.4$ eV. The scattering rate is
found to be strongly anisotropic, with a minimum along the (0,0)-($\pi,\pi$)
direction. A possible connection to a quantum-critical point is discussed.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:54:44 GMT"
},
{
"version": "v2",
"created": "Mon, 12 Jul 2010 15:45:11 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Chang",
"J.",
""
],
[
"Shi",
"M.",
""
],
[
"Pailhes",
"S.",
""
],
[
"Maansson",
"M.",
""
],
[
"Claesson",
"T.",
""
],
[
"Tjernberg",
"O.",
""
],
[
"Bendounan",
"A.",
""
],
[
"Sassa",
"Y.",
""
],
[
"Patthey",
"L.",
""
],
[
"Momono",
"N.",
""
],
[
"Oda",
"M.",
""
],
[
"Ido",
"M.",
""
],
[
"Mudry",
"S. Guerrero C.",
""
],
[
"Mesot",
"J.",
""
]
] |
0708.2783 | Janusz Garecki Prof | Janusz Garecki | On Energy of the Friedman Universes in Conformally Flat Coordinates | 11 pages, no figures, Revtex4. Abstract extended. Acknowledgements
added. References added | Acta Phys.Polon.B39:781-797,2008 | null | null | gr-qc | null | Recently many authors have calculated the energy of the Friedman universes by
using double index energy-momentum complexes in Cartesian comoving coordinates
$(t,x,y,z)$ and concluded that the flat and closed Friedman universes are
energy-free. We show in this paper by using Einstein canonical energy-momentum
complex and by doing calculations in conformally flat coordinates that such
conclusion is incorrect. The results obtained in this paper are compatible with
the results of the our previous paper \cite{Gar07} where we have used
coordinate-independent averaged relative energy-momentum tensors to analyze
Friedman universes.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:53:32 GMT"
},
{
"version": "v2",
"created": "Fri, 24 Aug 2007 12:45:14 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Sep 2007 12:30:28 GMT"
},
{
"version": "v4",
"created": "Tue, 2 Oct 2007 11:58:35 GMT"
}
] | 2011-04-26T00:00:00 | [
[
"Garecki",
"Janusz",
""
]
] |
0708.2784 | Ken-ichi Sugiyama | Ken-ichi Sugiyama | On a linear code from a configuration of affine lines | 13 pages | null | null | null | cs.IT cs.DM math.AG math.IT | null | We will show how to obtain a linear code from a configuration of affine lines
in general position and a suitable set of rational points. We will also explain
a new decoding algorithm based on the configuration, which seems to be quite
effective.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 08:57:07 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Sugiyama",
"Ken-ichi",
""
]
] |
0708.2785 | Jan Harm van der Walt | Jan Harm van der Walt | The uniform order convergence structure on ML(X) | 32 pages | null | null | null | math.GM math.AP math.GN | null | The aim of this paper is to set up appropriate uniform convergence spaces in
which to reformulate and enrich the Order Completion Method for nonlinear PDEs.
In this regard, we consider an appropriate space ML(X) of normal lower
semi-continuous functions. The space ML(X)= appears in the ring theory of C(X),
and its various extensions, as well as in the theory of nonlinear PDEs. We
define a uniform convergence structure on ML(X) such that the induced
convergence structure is the order convergence structure. The uniform
convergence space completion of ML(X) is constructed as the set of normal lower
semi-continuous functions. It is then shown how these ideas may be applied to
solve nonlinear PDEs. In particular, we construct generalized solutions to the
Navier-Stokes equations in three spatial dimensions, subject to an initial
condition.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:56:59 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Nov 2007 07:03:28 GMT"
}
] | 2007-11-19T00:00:00 | [
[
"van der Walt",
"Jan Harm",
""
]
] |
0708.2786 | Josef Pradler | Josef Pradler | Electroweak Contributions to Thermal Gravitino Production | 101 pages; diploma thesis; University of Vienna, Austria; Oct.2006 | null | null | MPP-2006-257 | hep-ph | null | At high temperatures, gravitinos are generated in inelastic scattering
processes with particles that are in thermal equilibrium with the hot
primordial plasma. We consider the regeneration of gravitinos that starts with
completion of reheating after inflation. Following a consistent
finite-temperature approach, we provide the complete result for the gravitino
production rate to leading order in the gauge couplings. Focusing on gravitino
dark matter scenarios we compute the relic density of thermally produced
gravitinos. Moreover, we show that a conceivable determination of the gravitino
mass at future colliders will allow for a unique test of the viability of
thermal leptogenesis in the laboratory.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:34:11 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Pradler",
"Josef",
""
]
] |
0708.2787 | Gunter Semmler | Gunter Semmler | Complete interpolating sequences, the discrete Muckenhoupt condition,
and conformal mapping | 26 pages, 3 figures | null | null | null | math.CV | null | We extend the parameterization of sine-type functions in terms of conformal
mappings onto slit domains given by Eremenko and Sodin to the more general case
of generating functions of real complete interpolating sequences. It turns out
that the cuts have to fulfill the discrete Muckenhoupt condition studied
earlier by Lyubarskii and Seip.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:31:07 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Semmler",
"Gunter",
""
]
] |
0708.2788 | Hanene Maghrebi | Han\`ene Maghrebi (LORIA), Amos David (LORIA) | Integrating users' needs into multimedia information retrieval system | null | Dans Third international conference on computer (2007) | null | null | cs.IR | null | The exponential growth of multimedia information and the development of
various communication media generated new problems at various levels including
the rate of flow of information, problems of storage and management. The
difficulty which arises is no longer the existence of information but rather
the access to this information. When designing multimedia information retrieval
system, it is appropriate to bear in mind the potential users and their
information needs. We assumed that multimedia information representation which
takes into account explicitly the users' needs and the cases of use could
contribute to the adaptation potentials of the system for the end-users. We
believe also that responses of multimedia information system would be more
relevant to the users' needs if the types of results to be used from the system
were identified before the design and development of the system. We propose the
integration of the users' information needs. More precisely integrating usage
contexts of resulting information in an information system (during creation and
feedback) should enhance more pertinent users' need. The first section of this
study is dedicated to traditional multimedia information systems and
specifically the approaches of representing multimedia information. Taking into
account the dynamism of users, these approaches do not permit the explicit
integration of the users' information needs. In this paper, we will present our
proposals based on economic intelligence approach. This approach emphasizes the
importance of starting any process of information retrieval witch the user
information need.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:04:49 GMT"
}
] | 2007-11-21T00:00:00 | [
[
"Maghrebi",
"Hanène",
"",
"LORIA"
],
[
"David",
"Amos",
"",
"LORIA"
]
] |
0708.2789 | Edmond Orignac | P. Pedri (Orsay), S. De Palo (Trieste), E. Orignac (ENS-Lyon), R.
Citro (Salerno), M. L. Chiofalo (SNS Pisa) | Collective excitations of trapped one-dimensional dipolar quantum gases | 5 pages, 2 EPS figures, RevTeX 4 | Phys. Rev. A 77, 015601 (2008) | 10.1103/PhysRevA.77.015601 | null | cond-mat.other cond-mat.str-el | null | We calculate the excitation modes of a 1D dipolar quantum gas confined in a
harmonic trap with frequency $\omega_0$ and predict how the frequency of the
breathing n=2 mode characterizes the interaction strength evolving from the
Tonks-Girardeau value $\omega_2=2\omega_0$ to the quasi-ordered, super-strongly
interacting value $\omega_2=\sqrt{5}\omega_0$. Our predictions are obtained
within a hydrodynamic Luttinger-Liquid theory after applying the Local Density
Approximation to the equation of state for the homogeneous dipolar gas, which
are in turn determined from Reptation Quantum Monte Carlo simulations. They are
shown to be in quite accurate agreement with the results of a sum-rule
approach. These effects can be observed in current experiments, revealing the
Luttinger-liquid nature of 1D dipolar Bose gases.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:05:44 GMT"
}
] | 2008-05-27T00:00:00 | [
[
"Pedri",
"P.",
"",
"Orsay"
],
[
"De Palo",
"S.",
"",
"Trieste"
],
[
"Orignac",
"E.",
"",
"ENS-Lyon"
],
[
"Citro",
"R.",
"",
"Salerno"
],
[
"Chiofalo",
"M. L.",
"",
"SNS Pisa"
]
] |
0708.2790 | Paula Coelho | P. Coelho, G. Bruzual, S. Charlot, A. Weiss, B. Barbuy, J. Ferguson | Spectral models for solar-scaled and alpha-enhanced stellar populations | Minor changes in the text and some figures to match the published
version. The definitive version is available at www.blackwell-synergy.com | 2007, MNRAS 382, 498 | 10.1111/j.1365-2966.2007.12364.x | null | astro-ph | null | We present the first models allowing one to explore in a consistent way the
influence of changes in the alpha-element-to-iron abundance ratio on the
high-resolution spectral properties of evolving stellar populations. The models
cover the wavelength range 300-1340nm at a resolution of FWHM=1AA, for
metallicities in the range 0.005<=Z<=0.048 and stellar population ages 3 to 14
Gyr. These models are based on a recent library of synthetic stellar spectra
and a new library of stellar evolutionary tracks, both computed for three
different [Fe/H] (-0.5,0.0 and 0.2) and two different [alpha/Fe] (0.0 and 0.4).
We expect our fully synthetic models to be primarily useful for evaluating the
differential effect of changes in the alpha/Fe ratio on spectral properties
such as broad-band colours and narrow spectral features. In addition, we assess
the accuracy of absolute model predictions in two ways: first, by comparing the
predictions of models for scaled-solar metal abundances [alpha/Fe]=0.0) to
those of existing models based on libraries of observed stellar spectra; and
secondly, by comparing the predictions of models for alpha-enhanced metal
abundances ([alpha/Fe]=0.4) to observed spectra of massive early-type galaxies
in the SDSS-DR4. We find that our models predict accurate strengths for those
spectral indices that are strongly sensitive to the abundances of Fe and alpha
elements. The predictions are less reliable for the strengths of other spectral
features, such as those dominated by the abundances of C and N, as expected
from the fact that the models do not yet allow one to explore the influence of
these elements in an independent way. We conclude that our models are a
powerful tool for extracting new information about the chemical properties of
galaxies for which high-quality spectra have been gathered by modern surveys.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:23:53 GMT"
},
{
"version": "v2",
"created": "Tue, 8 Jan 2008 14:07:06 GMT"
}
] | 2008-01-08T00:00:00 | [
[
"Coelho",
"P.",
""
],
[
"Bruzual",
"G.",
""
],
[
"Charlot",
"S.",
""
],
[
"Weiss",
"A.",
""
],
[
"Barbuy",
"B.",
""
],
[
"Ferguson",
"J.",
""
]
] |
0708.2791 | Luis Ramon Bellot Rubio | L.R. Bellot Rubio, S. Tsuneta, K. Ichimoto, Y. Katsukawa, B.W. Lites,
S. Nagata, T. Shimizu, R.A. Shine, Y. Suematsu, T.D. Tarbell, A.M. Title,
J.C. del Toro Iniesta | Vector spectropolarimetry of dark-cored penumbral filaments with Hinode | Accepted for publication in ApJ Letters. Use the Postscript version
for high quality figures | null | 10.1086/522604 | null | astro-ph | null | We present spectropolarimetric measurements of dark-cored penumbral filaments
taken with Hinode at a resolution of 0.3". Our observations demonstrate that
dark-cored filaments are more prominent in polarized light than in continuum
intensity. Far from disk center, the Stokes profiles emerging from these
structures are very asymmetric and show evidence for magnetic fields of
different inclinations along the line of sight, together with strong Evershed
flows of at least 6-7 km/s. In sunspots closer to disk center, dark-cored
penumbral filaments exhibit regular Stokes profiles with little asymmetries due
to the vanishing line-of-sight component of the horizontal Evershed flow. An
inversion of the observed spectra indicates that the magnetic field is weaker
and more inclined in the dark cores as compared with the surrounding bright
structures. This is compatible with the idea that dark-cored filaments are the
manifestation of flux tubes carrying hot Evershed flows.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:04:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rubio",
"L. R. Bellot",
""
],
[
"Tsuneta",
"S.",
""
],
[
"Ichimoto",
"K.",
""
],
[
"Katsukawa",
"Y.",
""
],
[
"Lites",
"B. W.",
""
],
[
"Nagata",
"S.",
""
],
[
"Shimizu",
"T.",
""
],
[
"Shine",
"R. A.",
""
],
[
"Suematsu",
"Y.",
""
],
[
"Tarbell",
"T. D.",
""
],
[
"Title",
"A. M.",
""
],
[
"Iniesta",
"J. C. del Toro",
""
]
] |
0708.2792 | Alexander Tartakovskii | M. N. Makhonin, A. I. Tartakovskii, I. Drouzas, A. B. Van'kov, T.
Wright, J. Skiba-Szymanska, A. Russell, V. I. Fal'ko, M. S. Skolnick, H.-Y.
Liu, M. Hopkinson | Long nuclear spin decay times controlled by optical pumping in
individual quantum dots | 4 pages, 3 figures, submitted to PRL | Phys. Rev. B 77, 125307 (2008) - Published March 6, 2008 | 10.1103/PhysRevB.77.125307 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | Nuclear polarization dynamics are measured in the nuclear spin bi-stability
regime in a single optically pumped InGaAs/GaAs quantum dot. The controlling
role of nuclear spin diffusion from the dot into the surrounding material is
revealed in pump-probe measurements of the non-linear nuclear spin dynamics. We
measure nuclear spin decay times in the range 0.2-5 sec, strongly dependent on
the optical pumping time. The long nuclear spin decay arises from polarization
of the material surrounding the dot by spin diffusion for long (>5sec) pumping
times. The time-resolved methods allow the detection of the unstable nuclear
polarization state in the bi-stability regime otherwise undetectable in cw
experiments.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:37:03 GMT"
},
{
"version": "v2",
"created": "Thu, 4 Oct 2007 17:32:08 GMT"
}
] | 2011-01-04T00:00:00 | [
[
"Makhonin",
"M. N.",
""
],
[
"Tartakovskii",
"A. I.",
""
],
[
"Drouzas",
"I.",
""
],
[
"Van'kov",
"A. B.",
""
],
[
"Wright",
"T.",
""
],
[
"Skiba-Szymanska",
"J.",
""
],
[
"Russell",
"A.",
""
],
[
"Fal'ko",
"V. I.",
""
],
[
"Skolnick",
"M. S.",
""
],
[
"Liu",
"H. -Y.",
""
],
[
"Hopkinson",
"M.",
""
]
] |
0708.2793 | Claudia M. Raiteri | C.M. Raiteri, M. Villata, V.M. Larionov, T. Pursimo, M.A. Ibrahimov,
K. Nilsson, et al | WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst
phase. Detection of the little and big blue bumps | 9 pages, 7 figures, accepted for publication in A&A | Astron.Astrophys.473:819-827,2007 | 10.1051/0004-6361:20078289 | null | astro-ph | null | The blazar 3C 454.3 underwent an unprecedented optical outburst in spring
2005. This was first followed by a mm and then by a cm radio outburst, which
peaked in February 2006. We report on follow-up observations by the WEBT to
study the multiwavelength emission in the post-outburst phase. XMM-Newton
observations on July and December 2006 added information on the X-ray and UV
fluxes. The source was in a faint state. The radio flux at the higher
frequencies showed a fast decreasing trend, which represents the tail of the
big radio outburst. It was followed by a quiescent state, common at all radio
frequencies. In contrast, moderate activity characterized the NIR and optical
light curves, with a progressive increase of the variability amplitude with
increasing wavelength. We ascribe this redder-when-brighter behaviour to the
presence of a "little blue bump" due to line emission from the broad line
region, which is clearly visible in the source SED during faint states.
Moreover, the data from the XMM-Newton OM reveal a rise of the SED in the UV,
suggesting the existence of a "big blue bump" due to thermal emission from the
accretion disc. The X-ray spectra are well fitted with a power-law model with
photoelectric absorption, possibly larger than the Galactic one. However, the
comparison with previous X-ray observations would imply that the amount of
absorbing matter is variable. Alternatively, the intrinsic X-ray spectrum
presents a curvature, which may depend on the X-ray brightness. In this case,
two scenarios are possible.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:37:55 GMT"
}
] | 2011-02-15T00:00:00 | [
[
"Raiteri",
"C. M.",
""
],
[
"Villata",
"M.",
""
],
[
"Larionov",
"V. M.",
""
],
[
"Pursimo",
"T.",
""
],
[
"Ibrahimov",
"M. A.",
""
],
[
"Nilsson",
"K.",
""
]
] |
0708.2794 | Brendon Lovett | Irene D'Amico, Brendon W. Lovett and Timothy P. Spiller | Freezing distributed entanglement in spin chains | 5 pages, to appear in Phys. Rev. A (Rapid Communication) | Phys. Rev. A 76 030302(R) (2007) | 10.1103/PhysRevA.76.030302 | null | quant-ph | null | We show how to freeze distributed entanglement that has been created from the
natural dynamics of spin chain systems. The technique that we propose simply
requires single-qubit operations and isolates the entanglement in specific
qubits at the ends of branches. Such frozen entanglement provides a useful
resource, for example for teleportation or distributed quantum processing. The
scheme can be applied to a wide range of systems -- including actual spin
systems and alternative qubit embodiments in strings of quantum dots, molecules
or atoms.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:46:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"D'Amico",
"Irene",
""
],
[
"Lovett",
"Brendon W.",
""
],
[
"Spiller",
"Timothy P.",
""
]
] |
0708.2795 | David Eichenberger | D. Eichenberger and D. Baeriswyl | Superconductivity and antiferromagnetism in the two-dimensional Hubbard
model: a variational study | 4 pages, 4 figures | null | 10.1103/PhysRevB.76.180504 | null | cond-mat.str-el cond-mat.supr-con | null | A variational ground state of the repulsive Hubbard model on a square lattice
is investigated numerically for an intermediate coupling strength (U = 8t) and
for moderate sizes (from 6 x 6 to 10 x 10). Our ansatz is clearly superior to
other widely used variational wave functions. The results for order parameters
and correlation functions provide new insight for the antiferromagnetic state
at half filling as well as strong evidence for a superconducting phase away
from half filling.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 09:54:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Eichenberger",
"D.",
""
],
[
"Baeriswyl",
"D.",
""
]
] |
0708.2796 | Roberto Gilli | R. Gilli, E. Daddi, R. Chary, M. Dickinson, D. Elbaz, M. Giavalisco,
M. Kitzbichler, D. Stern, E. Vanzella | The spatial clustering of mid-IR selected star forming galaxies at z ~ 1
in the GOODS fields | 19 pages, 15 figures. Accepted for publication in A&A. Style and
English improved | null | 10.1051/0004-6361:20077506 | null | astro-ph | null | We present the first spatial clustering measurements of z~1, 24um-selected,
star forming galaxies in the Great Observatories Origins Deep Survey (GOODS).
The sample under investigation includes 495 objects in GOODS-South and 811
objects in GOODS-North selected down to flux densities of f_24>20 uJy and
z_AB<23.5 mag, for which spectroscopic redshifts are available. The median
redshift, IR luminosity and star formation rate (SFR) of the samples are z~0.8,
L_IR~4.4 x 10^10 L_sun, and SFR~7.6 M_sun/yr, respectively. We measure the
projected correlation function w(r_p) on scales of r_p=0.06-10 h^-1 Mpc, from
which we derive a best fit comoving correlation length of r_0 = 4.0 +- 0.4 h^-1
Mpc and slope of gamma=1.5 +- 0.1 for the whole f_24>20uJy sample after
combining the two fields. We find indications of a larger correlation length
for objects of higher luminosity, with Luminous Infrared Galaxies (LIRGs,
L_IR>10^11 L_sun) reaching r_0~5.1 h^-1 Mpc. This would imply that galaxies
with larger SFRs are hosted in progressively more massive halos, reaching
minimum halo masses of ~3 x 10^12 M_sun for LIRGs. We compare our measurements
with the predictions from semi-analytic models based on the Millennium
simulation. The variance in the models is used to estimate the errors in our
GOODS clustering measurements, which are dominated by cosmic variance. The
measurements from the two GOODS fields are found to be consistent within the
errors. On scales of the GOODS fields, the real sources appear more strongly
clustered than objects in the Millennium-simulation based catalogs, if the
selection function is applied consistently. This suggests that star formation
at z~0.5-1 is being hosted in more massive halos and denser environments than
currently predicted by galaxy formation models.[truncated]
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:23:24 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Sep 2007 10:59:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gilli",
"R.",
""
],
[
"Daddi",
"E.",
""
],
[
"Chary",
"R.",
""
],
[
"Dickinson",
"M.",
""
],
[
"Elbaz",
"D.",
""
],
[
"Giavalisco",
"M.",
""
],
[
"Kitzbichler",
"M.",
""
],
[
"Stern",
"D.",
""
],
[
"Vanzella",
"E.",
""
]
] |
0708.2797 | Leila Powell | Leila C. Powell, Scott T. Kay, Arif Babul, Andisheh Mahdavi | Investigating the Relationship Between the Hot Gas and the Dark Matter
Components of Galaxy Clusters | 2 pages, 2 figures, to be published in proceedings of IAUS 244 "Dark
Galaxies and Lost Baryons" | null | 10.1017/S1743921307014342 | null | astro-ph | null | Various differences in galaxy cluster properties derived from X-ray and weak
lensing observations have been highlighted in the literature. One such
difference is the observation of mass concentrations in lensing maps which have
no X-ray counterparts (e.g. Jee, White, Ford et al. 2005). We investigate this
issue by identifying substructures in maps of projected total mass (analogous
to weak lensing mass reconstructions) and maps of projected X-ray surface
brightness for three simulated clusters. We then compare the 2D mass
substructures with both 3D subhalo data and the 2D X-ray substructures. Here we
present preliminary results from the first comparison, where we have assessed
the impact of projecting the data on subhalo identification.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 15:00:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Powell",
"Leila C.",
""
],
[
"Kay",
"Scott T.",
""
],
[
"Babul",
"Arif",
""
],
[
"Mahdavi",
"Andisheh",
""
]
] |
0708.2798 | Nissan Itzhaki | Nissan Itzhaki and Ely D. Kovetz | Inflection Point Inflation and Time Dependent Potentials in String
Theory | 15 pages, 2 figures, refs. added | JHEP 0710:054,2007 | 10.1088/1126-6708/2007/10/054 | null | hep-th astro-ph.CO hep-ph | null | We consider models of inflection point inflation. The main drawback of such
models is that they suffer from the overshoot problem. Namely the initial
condition should be fine tuned to be near the inflection point for the universe
to inflate. We show that stringy realizations of inflection point inflation are
common and offer a natural resolution to the overshoot problem.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:03:23 GMT"
},
{
"version": "v2",
"created": "Sun, 2 Sep 2007 08:16:22 GMT"
}
] | 2010-04-30T00:00:00 | [
[
"Itzhaki",
"Nissan",
""
],
[
"Kovetz",
"Ely D.",
""
]
] |
0708.2799 | Levay Peter | P\'eter L\'evay | A three-qubit interpretation of BPS and non-BPS STU black holes | 35 pages | Phys.Rev.D76:106011,2007 | 10.1103/PhysRevD.76.106011 | null | hep-th astro-ph quant-ph | null | Following the recent trend we develop further the black hole analogy between
quantum information theory and the theory of extremal stringy black hole
solutions. We show that the three-qubit interpretation of supersymmetric black
hole solutions in the STU model can be extended also to include
non-supersymmetric ones. First we show that the black hole potential can be
expressed as one half the norm of a suitably chosen three-qubit entangled state
containing the quantized charges and the moduli. The extremization of the black
hole potential in terms of this entangled state amounts to either supressing
bit flip errors (BPS-case) or allowing very special types of flips transforming
the states between different classes of non-BPS solutions. We are illustrating
our results for the example of the D2-D6 system. In this case the bit flip
errors are corresponding to sign flip errors of the charges originating from
the number of D2 branes. After moduli stabilization the states depending
entirely on the charges are maximally entangled graph states (of the triangle
graph) well-known from quantum information theory. An N=8 interpretation of the
STU-model in terms of a mixed state with fermionic purifications is also given.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:09:02 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lévay",
"Péter",
""
]
] |
0708.2800 | Gnedin Yuri Nickolaevich | M.Yu. Piotrovich, Yu.N. Gnedin, T.M. Natsvlishvili | Synchrotron Self-Absorption Process in GRBs and the Isotropic Energy -
Peak Energy Fundamental Relation | 5 pages | null | null | null | astro-ph | null | The existence of strong correlation between the peak luminosity (and/or
bolometric energetics) of Gamma Ray Bursts (GRB) is one of the most intrigue
problem of GRB physics. This correlation is not yet understood. Here we
demonstrate that this correlation can be explained in framework of synchrotron
self-absorption (SSA) mechanism of GRB prompt emission. We estimate the
magnetic field strength of the central engine at the level $B\sim 10^{14}
(10^3/\Gamma)^3 (1+z)^2$, where $\Gamma$ is the Lorentz factor of fireball.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:27:37 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Piotrovich",
"M. Yu.",
""
],
[
"Gnedin",
"Yu. N.",
""
],
[
"Natsvlishvili",
"T. M.",
""
]
] |
0708.2801 | Nikodem Szpak | Nikodem Szpak | Simple proof of a useful pointwise estimate for the wave equation | 7 pages; some minor errors corrected; numerical values of the bounds
added | null | null | null | math-ph math.MP | null | We give a simple proof of a pointwise decay estimate in 3+1 dimensions stated
in two versions, making advantage of a particular simplicity of inverting the
spherically symmetric part of the wave operator and of the comparison theorem.
We briefly explain the role of this estimate in proving decay estimates for
nonlinear wave equations or wave equations with potential terms.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:40:05 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Oct 2007 14:12:29 GMT"
}
] | 2007-10-09T00:00:00 | [
[
"Szpak",
"Nikodem",
""
]
] |
0708.2802 | Alexander V. Kuznetsov | A.V. Kuznetsov and N.V. Mikheev (Yaroslavl State (P.G. Demidov)
University, Russia) | Plasma induced neutrino spin-flip in a supernova and new bounds on the
neutrino magnetic moment | 10 pages, LaTeX, 6 eps figures, based on the talk presented at the
XIV International School ``Particles and Cosmology'', Baksan Valley,
Kabardino Balkaria, Russia, April 16-21, 2007, to appear in the Proceedings | null | null | YARU-HE-07/02 | hep-ph | null | The neutrino chirality-flip process under the conditions of the supernova
core is investigated in detail with the plasma polarization effects in the
photon propagator taken into account in a more complete form than in earlier
publications. It is shown in part that the contribution of the proton fraction
of plasma is essential. New upper bounds on the neutrino magnetic moment are
obtained: mu_nu < (0.5 - 1.1) 10^{-12} mu_B from the limit on the supernova
core luminosity for nu_R emission, and mu_nu < (0.4 - 0.6) 10^{-12} mu_B from
the limit on the averaged time of the left-handed neutrino washing out. The
best upper bound on the neutrino magnetic moment from SN1987A is improved by
the factor of 3 to 7.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:53:41 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Kuznetsov",
"A. V.",
"",
"Yaroslavl State"
],
[
"Mikheev",
"N. V.",
"",
"Yaroslavl State"
]
] |
0708.2803 | Giuseppina Orlandini | V. D. Efros, W. Leidemann, G. Orlandini, N. Barnea | The Lorentz Integral Transform (LIT) method and its applications to
perturbation induced reactions | 83 pages, 31 figures. Topical review. Corrected typos | J. Phys. G: Nucl. Part. Phys. 34 (2007) R459-R528 | 10.1088/0954-3899/34/12/R02 | null | nucl-th | null | The LIT method has allowed ab initio calculations of electroweak cross
sections in light nuclear systems. This review presents a description of the
method from both a general and a more technical point of view, as well as a
summary of the results obtained by its application. The remarkable features of
the LIT approach, which make it particularly efficient in dealing with a
general reaction involving continuum states, are underlined. Emphasis is given
on the results obtained for electroweak cross sections of few--nucleon systems.
Their implications for the present understanding of microscopic nuclear
dynamics are discussed.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:56:54 GMT"
},
{
"version": "v2",
"created": "Tue, 22 Jan 2008 16:45:23 GMT"
}
] | 2008-01-22T00:00:00 | [
[
"Efros",
"V. D.",
""
],
[
"Leidemann",
"W.",
""
],
[
"Orlandini",
"G.",
""
],
[
"Barnea",
"N.",
""
]
] |
0708.2804 | Yi Hong Dr | Ezio Biglieri, Yi Hong, Emanuele Viterbo | On Fast-Decodable Space-Time Block Codes | submitted to IEEE trans IT | null | null | null | cs.IT math.IT | null | We focus on full-rate, fast-decodable space-time block codes (STBCs) for 2x2
and 4x2 multiple-input multiple-output (MIMO) transmission. We first derive
conditions for reduced-complexity maximum-likelihood decoding, and apply them
to a unified analysis of two families of 2x2 STBCs that were recently proposed.
In particular, we describe a reduced-complexity sphere decoding algorithm
suitable for QAM signal constellations. Next, we derive a novel
reduced-complexity 4x2 STBC, and show that it outperforms all previously known
codes with certain constellations.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 10:57:59 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Mar 2008 14:58:25 GMT"
}
] | 2008-03-18T00:00:00 | [
[
"Biglieri",
"Ezio",
""
],
[
"Hong",
"Yi",
""
],
[
"Viterbo",
"Emanuele",
""
]
] |
0708.2805 | Zigang Huang | Zi-Gang Huang, Zhi-Xi Wu, Jian-Yue Guan, An-Cai Wu, and Ying-Hai Wang | The public goods game on homogeneous and heterogeneous networks:
investment strategy according to the pool size | 6 pages, 5 figures | null | null | null | q-fin.GN physics.gen-ph physics.soc-ph q-fin.PM | null | We propose an extended public goods interaction model to study the evolution
of cooperation in heterogeneous population. The investors are arranged on the
well known scale-free type network, the Barab\'{a}si-Albert model. Each
investor is supposed to preferentially distribute capital to pools in its
portfolio based on the knowledge of pool sizes. The extent that investors
prefer larger pools is determined by investment strategy denoted by a tunable
parameter $\alpha$, with larger $\alpha$ corresponding to more preference to
larger pools. As comparison, we also study this interaction model on square
lattice, and find that the heterogeneity contacts favors cooperation.
Additionally, the influence of local topology to the game dynamics under
different $\alpha$ strategies are discussed. It is found that the system with
smaller $\alpha$ strategy can perform comparatively better than the larger
$\alpha$ ones.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:05:01 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Huang",
"Zi-Gang",
""
],
[
"Wu",
"Zhi-Xi",
""
],
[
"Guan",
"Jian-Yue",
""
],
[
"Wu",
"An-Cai",
""
],
[
"Wang",
"Ying-Hai",
""
]
] |
0708.2806 | Leonard Todjihounde Prof. | J. Jost, L. Todjihounde | Harmonic nets in metric spaces | A slightly edited version wil appear in Pacific Journal of
Mathematics | null | null | null | math.MG | null | We investigate harmonic maps from weighted graphs into metric spaces that
locally admit unique centers of gravity, like Alexandrov spaces with upper
curvature bounds. We prove an existence result by constructing an iterative
geometric process that converges to such maps, called harmonic nets for short.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:06:06 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Jost",
"J.",
""
],
[
"Todjihounde",
"L.",
""
]
] |
0708.2807 | Jonna Koponen | UKQCD Collaboration: J. Koponen | Energies of B_s meson excited states - a lattice study | 35 pages. v3: Data from two new lattices added. New results in
several chapters | Phys.Rev.D78:074509,2008 | 10.1103/PhysRevD.78.074509 | HIP-2007-44/TH | hep-lat hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a follow-up to our earlier work on the energies and radial
distributions of heavy-light mesons. The heavy quark is taken to be static
(infinitely heavy) and the light quark has a mass about that of the strange
quark. We now concentrate on the energies of the excited states with higher
angular momentum and with a radial node. A new improvement is the use of
hypercubic blocking in the time direction.
The calculation is carried out with dynamical fermions on a 16 cubed times 32
lattice with a lattice spacing approximately 0.1 fm generated using a
non-perturbatively improved clover action.
In nature the closest equivalent of this heavy-light system is the B_s meson,
which allows us to compare our lattice calculations to experimental results
(where available) or to give a prediction where the excited states,
particularly P-wave states, should lie. We pay special attention to the
spin-orbit splitting, to see which one of the states (for a given angular
momentum L) has the lower energy. An attempt is made to understand these
results in terms of the Dirac equation.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:09:04 GMT"
},
{
"version": "v2",
"created": "Wed, 22 Aug 2007 12:32:01 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Aug 2008 08:40:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"UKQCD Collaboration",
"",
""
],
[
"Koponen",
"J.",
""
]
] |
0708.2808 | Paul Hoyer | Paul Hoyer | Inclusive Perspectives | Concluding talk at the Workshop on "Exclusive Reactions at High
Momentum Transfer", Jefferson Lab, 21-24 May 2007. 14 pages, 10 figures | null | 10.1142/9789812796950_0004 | HIP-2007-43/TH | hep-ph | null | I discuss the relation between inclusive and exclusive dynamics suggested by
Bloom-Gilman duality. Duality implies the simultaneous applicability of two
distinct limits, the standard DIS limit of hard inclusive processes taken at
fixed xB and a limit where the hadronic mass is held fixed. I review
experimental evidence for the relevance of the fixed mass limit in inclusive
processes at high xF. Semi-local duality suggests that inclusive and exclusive
processes occur on the same target Fock states. DIS scaling then implies that
the Fock states contributing to hard exclusive processes have a large
transverse size, i.e., that the hard scattering occurs off a single parton
which carries a large fraction of the hadron momentum.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:12:27 GMT"
}
] | 2017-08-23T00:00:00 | [
[
"Hoyer",
"Paul",
""
]
] |
0708.2809 | Holger F. Hofmann | Takafumi Ono and Holger F. Hofmann | Quantum enhancement of N-photon phase sensitivity by interferometric
addition of down-converted photon pairs to weak coherent light | 21 pages, including 6 figures. Extended version gives more details on
down-conversion efficiencies and clarifies the relation between phase
sensitivity and squeezing. The title has been changed in order to avoid
misunderstandings regarding these concepts | J. Phys. B: At. Mol. Opt. Phys. 41, 095502 (2008) | 10.1088/0953-4075/41/9/095502 | null | quant-ph | null | It is shown that the addition of down-converted photon pairs to coherent
laser light enhances the N-photon phase sensitivity due to the quantum
interference between components of the same total photon number. Since most of
the photons originate from the coherent laser light, this method of obtaining
non-classical N-photon states is much more efficient than methods based
entirely on parametrically down-converted photons. Specifically, it is possible
to achieve an optimal phase sensitivity of about delta phi^2=1/N^(3/2), equal
to the geometric mean of the standard quantum limit and the Heisenberg limit,
when the average number of down-converted photons contributing to the N-photon
state approaches (N/2)^(1/2).
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:00:55 GMT"
},
{
"version": "v2",
"created": "Tue, 1 Apr 2008 03:37:57 GMT"
}
] | 2008-04-23T00:00:00 | [
[
"Ono",
"Takafumi",
""
],
[
"Hofmann",
"Holger F.",
""
]
] |
0708.2810 | J. Schaffner-Bielich | Irina Sagert, Mirjam Wietoska, Jurgen Schaffner-Bielich, Christian
Sturm | Is a soft nuclear equation of state extracted from heavy-ion data
incompatible with pulsar data? | 8 pages, 1 figure, contribution to the proceedings of the
international conference on 'Nuclear Physics in Astrophysics III', Dresden,
Germany, March 26-31, 2007, minor corrections to match published version, JPG
in press | J.Phys.G35:014053,2008 | 10.1088/0954-3899/35/1/014053 | null | astro-ph nucl-th | null | We discuss the recent constraints on the nuclear equation of state from
pulsar mass measurements and from subthreshold production of kaons in heavy-ion
collisions. While recent pulsar data points towards a hard equation of state,
the analysis of the heavy-ion data allows only for soft equations of state. We
resolve the apparent contradiction by considering the different density regimes
probed. We argue that future measurements of global properties of low-mass
pulsars can serve as an excellent cross-check to heavy-ion data.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:25:47 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Sep 2007 07:37:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sagert",
"Irina",
""
],
[
"Wietoska",
"Mirjam",
""
],
[
"Schaffner-Bielich",
"Jurgen",
""
],
[
"Sturm",
"Christian",
""
]
] |
0708.2811 | Elica Kyoseva | P. A. Ivanov, E. S. Kyoseva, and N. V. Vitanov | Engineering of arbitrary U(N) transformations by quantum Householder
reflections | 8 pages, 2 figures | Phys. Rev. A 74, 022323 (2006) | 10.1103/PhysRevA.74.022323 | null | quant-ph | null | We propose a simple physical implementation of the quantum Householder
reflection (QHR) M(v)=I-2|v><v| in a quantum system of N degenerate states
(forming a qunit) coupled simultaneously to an ancillary (excited) state by N
resonant or nearly resonant pulsed external fields. We also introduce the
generalized QHR M(v;k)=I+(exp{ik}-1)|v><v|, which can be produced in the same
N-pod system when the fields are appropriately detuned from resonance with the
excited state. We use these two operators as building blocks in constructing
arbitrary preselected unitary transformations. We show that the most general
U(N) transformation can be factorized (and thereby produced) by either N-1
standard QHRs and an N-dimensional phase gate, or N-1 generalized QHRs and a
one-dimensional phase gate. Viewed mathematically, these QHR factorizations
provide parametrizations of the U(N) group. As an example, we propose a recipe
for constructing the quantum Fourier transform (QFT) by at most N interaction
steps. For example, QFT requires a single QHR for N=2, and only two QHRs for
N=3 and 4.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:26:09 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ivanov",
"P. A.",
""
],
[
"Kyoseva",
"E. S.",
""
],
[
"Vitanov",
"N. V.",
""
]
] |
0708.2812 | Prasanta Das Kumar | Prasanta Kumar Das | Unparticle effects in Supernovae cooling | 9 pages, 2 figures, text is modified, references updated and version
accepted for publication in Phys. Rev. D | Phys.Rev.D76:123012,2007 | 10.1103/PhysRevD.76.123012 | null | hep-ph | null | Recently H. Georgi suggested that a scale invariant unparticle
${\mathcal{U}}$ sector with an infrared fixed point at high energy can couple
with the SM matter via a higher-dimensional operator suppressed by a high
cut-off scale. Intense phenomenological search of this unparticle sector in the
collider and flavour physics context has already been made. Here we explore
it's impact in cosmology, particularly it's possible role in the supernovae
cooling. We found that the energy-loss rate (and thus the cooling) is strongly
dependent on the effective scale \LdaU and the anomalous dimension \dU of this
unparticle theory.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:28:21 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Nov 2007 14:23:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Das",
"Prasanta Kumar",
""
]
] |
0708.2813 | Tomotsugu Wakasa | T. Wakasa, M. Dozono, E. Ihara, S. Asaji, K. Fujita, K. Hatanaka, M.
Ichimura, T. Ishida, T. Kaneda, H. Matsubara, Y. Nagasue, T. Noro, Y. Sakemi,
Y. Shimizu, H. Takeda, Y. Tameshige, A. Tamii, and Y. Yamada | Study of nuclear correlation effects via 12C(p,n)12N(g.s.,1+) at 296 MeV | 5 figures, submitted to Phys. Lett. B | Phys.Lett.B656:38-44,2007 | 10.1016/j.physletb.2007.10.017 | null | nucl-ex | null | We report measurements of the cross section and a complete set of
polarization observables for the Gamow--Teller ${}^{12}{\rm
C}(\vec{p},\vec{n}){}^{12}{\rm N}({\rm g.s.},1^+)$ reaction at a bombarding
energy of 296 MeV.
The data are compared with distorted wave impulse approximation calculations
employing transition form factors normalized to reproduce the observed
beta-decay $ft$ value.
The cross section is significantly under-predicted by the calculations at
momentum transfers $q \gtrsim $ 0.5 ${\rm fm^{-1}}$.
The discrepancy is partly resolved by considering the non-locality of the
nuclear mean field. However, the calculations still under-predict the cross
section at large momentum transfers of $q$ $\simeq$ 1.6 ${\rm fm^{-1}}$.
We also performed calculations employing random phase approximation response
functions and found that the observed enhancement can be attributed in part to
pionic correlations in nuclei.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:31:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wakasa",
"T.",
""
],
[
"Dozono",
"M.",
""
],
[
"Ihara",
"E.",
""
],
[
"Asaji",
"S.",
""
],
[
"Fujita",
"K.",
""
],
[
"Hatanaka",
"K.",
""
],
[
"Ichimura",
"M.",
""
],
[
"Ishida",
"T.",
""
],
[
"Kaneda",
"T.",
""
],
[
"Matsubara",
"H.",
""
],
[
"Nagasue",
"Y.",
""
],
[
"Noro",
"T.",
""
],
[
"Sakemi",
"Y.",
""
],
[
"Shimizu",
"Y.",
""
],
[
"Takeda",
"H.",
""
],
[
"Tameshige",
"Y.",
""
],
[
"Tamii",
"A.",
""
],
[
"Yamada",
"Y.",
""
]
] |
0708.2814 | Chaitanya Das Pemmaraju Mr | C. D. Pemmaraju, S. Sanvito, and K. Burke | Polarizability of molecular chains: does one need exact exchange? | 4 pages, 3 figures | null | null | null | physics.atm-clus cond-mat.mtrl-sci physics.comp-ph | null | Standard density functional approximations greatly over-estimate the static
polarizability of longchain polymers, but Hartree-Fock or exact exchange
calculations do not. Simple self-interaction corrected (SIC) approximations can
be even better than exact exchange, while their computational cost can scale
only linearly with the number of occupied orbitals.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:32:25 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Pemmaraju",
"C. D.",
""
],
[
"Sanvito",
"S.",
""
],
[
"Burke",
"K.",
""
]
] |
0708.2815 | Sintayehu Tesfa Woldemariam Mr | Sintayehu Tesfa | Driven degenerate three-level cascade laser | 8 pages, 8 figures | null | null | null | quant-ph | null | We analyze a degenerate three-level cascade laser coupled to an external
coherent light via one of the coupler mirrors and vacuum reservoir in the
other, employing the stochastic differential equation associated with the
normal ordering. We study the squeezing properties and also calculate the mean
photon number of the cavity radiation. It turns out that the generated light
exhibits up to 98.3% squeezing under certain conditions pertaining to the
initial preparation of the superposition and the amplitude of the driving
radiation. Moreover, the mean photon number is found to be large where there is
a better squeezing. Hence it is believed that the system under consideration
can generate an intense squeezed light.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:02:38 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Tesfa",
"Sintayehu",
""
]
] |
0708.2816 | Pankaj Jain | Pramoda Kumar Samal, Rajib Saha, Pankaj Jain and John P. Ralston | Testing Isotropy of Cosmic Microwave Background Radiation | 40 pages 15 figures | Mon.Not.Roy.Astron.Soc.385:1718,2008 | 10.1111/j.1365-2966.2008.12960.x | null | astro-ph | null | We introduce new symmetry-based methods to test for isotropy in cosmic
microwave background radiation. Each angular multipole is factored into unique
products of power eigenvectors, related multipoles and singular values that
provide 2 new rotationally invariant measures mode by mode. The power entropy
and directional entropy are new tests of randomness that are independent of the
usual CMB power. Simulated galactic plane contamination is readily identified,
and the new procedures mesh perfectly with linear transformations employed for
windowed-sky analysis. The ILC -WMAP data maps show 7 axes well aligned with
one another and the direction Virgo. Parameter free statistics find 12
independent cases of extraordinary axial alignment, low power entropy, or both
having 5% probability or lower in an isotropic distribution. Isotropy of the
ILC maps is ruled out to confidence levels of better than 99.9%, whether or not
coincidences with other puzzles coming from the Virgo axis are included. Our
work shows that anisotropy is not confined to the low l region, but extends
over a much larger l range.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:42:33 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Samal",
"Pramoda Kumar",
""
],
[
"Saha",
"Rajib",
""
],
[
"Jain",
"Pankaj",
""
],
[
"Ralston",
"John P.",
""
]
] |
0708.2817 | Thomas Lorenz | J. Rohrkamp, O. Heyer, T. Fickenscher, R. Poettgen, S. Jodlauk, H.
Hartmann, T. Lorenz, J.A. Mydosh | Thermal expansion of the magnetically ordering intermetallics RTMg (R =
Eu, Gd and T = Ag, Au) | 6 pages, 3 figures | J. Phys.: Condens. Matter 19, 486204 (2007) | 10.1088/0953-8984/19/48/486204 | null | cond-mat.mtrl-sci cond-mat.other | null | We report measurements of the thermal expansion for two Eu$^{+2}$- and two
Gd$^{+3}$-based intermetallics which exhibit ferro- or antiferromagnetic phase
transitions. These materials show sharp positive (EuAgMg and GdAuMg) and
negative (EuAuMg and GdAgMg) peaks in the temperature dependence of the thermal
expansion coefficient $\alpha$ which become smeared and/or displaced in an
external magnetic field. Together with specific heat data we determine the
initial pressure dependences of the transition temperatures at ambient pressure
using the Ehrenfest or Clausius-Clapeyron relation. We find large pressure
dependences indicating strong spin-phonon coupling, in particular for GdAgMg
and EuAuMg where a quantum phase transition might be reached at moderate
pressures of a few GPa.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:48:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rohrkamp",
"J.",
""
],
[
"Heyer",
"O.",
""
],
[
"Fickenscher",
"T.",
""
],
[
"Poettgen",
"R.",
""
],
[
"Jodlauk",
"S.",
""
],
[
"Hartmann",
"H.",
""
],
[
"Lorenz",
"T.",
""
],
[
"Mydosh",
"J. A.",
""
]
] |
0708.2818 | Shin Nakamura | Shin Nakamura, Yunseok Seo, Sang-Jin Sin and K. P. Yogendran | Baryon-charge Chemical Potential in AdS/CFT | Revtex4, 36 pages with 23 figures | Prog.Theor.Phys.120:51-76,2008 | 10.1143/PTP.120.51 | null | hep-th hep-ph nucl-th | null | We present a closed framework of AdS/CFT with finite U(1)B-charge chemical
potential. We show how the gauge-invariant identification of the chemical
potential with the bulk gauge field emerges from the standard AdS/CFT
dictionary. Physical importance and necessity of the Minkowski embeddings
within the present framework is also shown numerically in the D3-D7 systems. We
point out that the D3-D7 model with only the black-hole embeddings does not
have the low-temperature and low-chemical-potential region in the
grand-canonical ensemble, hence it is incomplete. A physical interpretation
that explains these numerical results is also proposed.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:49:41 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nakamura",
"Shin",
""
],
[
"Seo",
"Yunseok",
""
],
[
"Sin",
"Sang-Jin",
""
],
[
"Yogendran",
"K. P.",
""
]
] |
0708.2819 | Evgeny Sokolov Victorovich | E. V. Sokolov | On the cyclic subgroup separability of free products of two groups with
amalgamated subgroup | 10 pages; for other papers of this author, see
http://icu.ivanovo.ac.ru/tg-seminar | Lobachevskii Journal of Mathematics. 11 (2002). 27-38 | null | null | math.GR | null | Let $G$ be a free product of two groups with amalgamated subgroup, $\pi$ be
either the set of all prime numbers or the one-element set \{$p$\} for some
prime number $p$. Denote by $\Sigma$ the family of all cyclic subgroups of
group $G$, which are separable in the class of all finite $\pi$-groups.
Obviously, cyclic subgroups of the free factors, which aren't separable in
these factors by the family of all normal subgroups of finite $\pi$-index of
group $G$, the subgroups conjugated with them and all subgroups, which aren't
$\pi^{\prime}$-isolated, don't belong to $\Sigma$. Some sufficient conditions
are obtained for $\Sigma$ to coincide with the family of all other
$\pi^{\prime}$-isolated cyclic subgroups of group $G$. It is proved, in
particular, that the residual $p$-finiteness of a free product with cyclic
amalgamation implies the $p$-separability of all $p^{\prime}$-isolated cyclic
subgroups if the free factors are free or finitely generated residually
$p$-finite nilpotent groups.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 11:59:53 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Sokolov",
"E. V.",
""
]
] |
0708.2820 | Ali Murat Guler | The CHORUS Collaboration | Associated Charm Production in Neutrino-Nucleus Interactions | 10 pages, 4 figures | Eur.Phys.J.C52:543-552,2007 | 10.1140/epjc/s10052-007-0410-8 | null | hep-ex | null | In this paper a search for associated charm production both in neutral and
charged current $\nu$-nucleus interactions is presented. The improvement of
automatic scanning systems in the {CHORUS} experiment allows an efficient
search to be performed in emulsion for short-lived particles. Hence a search
for rare processes, like the associated charm production, becomes possible
through the observation of the double charm-decay topology with a very low
background. About 130,000 $\nu$ interactions located in the emulsion target
have been analysed. Three events with two charm decays have been observed in
the neutral-current sample with an estimated background of 0.18$\pm$0.05. The
relative rate of the associated charm cross-section in deep inelastic $\nu$
interactions, $\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}=
(3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3}$ has been
measured. One event with two charm decays has been observed in charged-current
$\nu_\mu$ interactions with an estimated background of 0.18$\pm$0.06 and the
upper limit on associated charm production in charged-current interactions at
90% C.L. has been found to be $\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} <
9.69 \times 10^{-4}$.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 15:11:19 GMT"
}
] | 2012-08-27T00:00:00 | [
[
"The CHORUS Collaboration",
"",
""
]
] |
0708.2821 | Wolfgang Trautmann | J. Lukasik and W. Trautmann (The INDRA and ALADiN Collaborations) | Collective flow in heavy ion collisions at intermediate energies | 3 pages, 2 figures, contributed talk at INPC, Tokyo, June 3-8, 2007,
to appear in the proceedings | Proc. International Nuclear Physics Conference (INPC2007), (Tokyo
2007) Volume 2, pp. 513-515 | null | null | nucl-ex | null | We present results of a flow analysis for the set of reactions of 124,129Xe
projectiles and 112,124Sn targets at incident energies 100 and 150 A MeV
studied with the INDRA detector at GSI. The dependence on centrality and on p_t
of the directed and elliptic flow are determined for isotopically selected
reaction products with Z \le 3. The flow parameters v_1 and v_2, in general,
follow expected trends but isotopic effects are small.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:30:00 GMT"
}
] | 2008-08-21T00:00:00 | [
[
"Lukasik",
"J.",
"",
"The INDRA and ALADiN Collaborations"
],
[
"Trautmann",
"W.",
"",
"The INDRA and ALADiN Collaborations"
]
] |
0708.2822 | Edo Noordermeer | E. Noordermeer and M.A.W. Verheijen | The high mass end of the Tully-Fisher relation | 12 pages, 7 figures. Accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12369.x | null | astro-ph | null | We study the location of massive disk galaxies on the Tully-Fisher relation.
Using a combination of K-band photometry and high-quality rotation curves, we
show that in traditional formulations of the TF relation (using the width of
the global HI profile or the maximum rotation velocity), galaxies with rotation
velocities larger than 200 km/s lie systematically to the right of the relation
defined by less massive systems, causing a characteristic `kink' in the
relations. Massive, early-type disk galaxies in particular have a large offset,
up to 1.5 magnitudes, from the main relation defined by less massive and
later-type spirals.
The presence of a change in slope at the high-mass end of the Tully-Fisher
relation has important consequences for the use of the Tully-Fisher relation as
a tool for estimating distances to galaxies or for probing galaxy evolution. In
particular, the luminosity evolution of massive galaxies since z = 1 may have
been significantly larger than estimated in several recent studies.
We also show that many of the galaxies with the largest offsets have
declining rotation curves and that the change in slope largely disappears when
we use the asymptotic rotation velocity as kinematic parameter. The remaining
deviations from linearity can be removed when we simultaneously use the total
baryonic mass (stars + gas) instead of the optical or near-infrared luminosity.
Our results strengthen the view that the Tully-Fisher relation fundamentally
links the mass of dark matter haloes with the total baryonic mass embedded in
them.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:06:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Noordermeer",
"E.",
""
],
[
"Verheijen",
"M. A. W.",
""
]
] |
0708.2823 | Philippe Claudin | A. Fourri\`ere, P. Claudin and B. Andreotti | Bedforms in a turbulent stream.Part 1: Turbulent flow over topography | 49 pages, 23 figures, new version resubmitted to J. Fluid Mech | null | null | null | cond-mat.soft | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the context of subaqueous ripple and dune formation, we present here a
Reynolds averaged calculation of the turbulent flow over a topography. We
perform a weakly non-linear expansion of the velocity field, sufficiently
accurate to recover the separation of streamlines and the formation of a
recirculation bubble above some aspect ratio. The basal stresses are
investigated in details; in particular, we show that the phase shift of the
shear stress with respect to the topography, responsible for the formation of
bedforms, appears in an inner boundary layer where shear stress and pressure
gradients balance. We study the sensitivity of the calculation with respect to
(i) the choice of the turbulence closure, (ii) the motion of the bottom (growth
or propagation), (iii) the physics at work in the surface layer, responsible
for the hydrodynamic roughness of the bottom, (iv) the aspect ratio of the
bedform and (v) the effect of the free surface, which can be interpreted in
terms of standing gravity waves excited by topography. The most important
effects are those of points (iii) to (v). We show that the dynamical mechanisms
controlling the hydrodynamical roughness (mixing due to roughness elements,
viscosity, sediment transport, etc) have an influence on the basal shear stress
when the thickness of the surface layer is comparable to that of the inner
layer. We evidence that non-linear effects tend to oppose linear ones and are
of the same order for bedform aspect ratios of the order of 1/10. We show that
the influence of the free surface on the basal shear stress is dominant when
the wavelength is large compared to the flow depth, so that the inner layer
extends throughout the flow and in the resonant conditions, and when the
downstream material velocity balances the upstream wave propagation.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:09:25 GMT"
},
{
"version": "v2",
"created": "Thu, 22 May 2008 08:32:15 GMT"
},
{
"version": "v3",
"created": "Fri, 14 Nov 2008 16:32:00 GMT"
}
] | 2008-11-14T00:00:00 | [
[
"Fourrière",
"A.",
""
],
[
"Claudin",
"P.",
""
],
[
"Andreotti",
"B.",
""
]
] |
0708.2824 | Robert Nichol | Robert C. Nichol (ICG Portsmouth) | Cosmology with Galaxy Correlations | Invited review for a special issue of "General Relativity and
Gravitation" on Dark Energy | Gen.Rel.Grav.40:249-267,2008 | 10.1007/s10714-007-0546-8 | null | astro-ph | null | In this review, I outline the use of galaxy correlations to constrain
cosmological parameters. As with the Cosmic Microwave Background (CMB), the
density of dark and baryonic matter imprints important scales on the
fluctuations of matter and thus the clustering of galaxies, e.g., the particle
horizon at matter--radiation equality and the sound horizon at recombination.
Precision measurements of these scales from the Baryon Acoustic Oscillations
(BAO) and the large scale shape of the power spectrum of galaxy clustering
provide constraints on Omega_m h^2. Recent measurements from the Sloan Digital
Sky Survey (SDSS) and 2dF Galaxy Redshift Survey (2dFGRS) strongly suggest that
Omega_m < 0.3. This forms the basic evidence for a flat Universe dominated by a
Cosmological Constant (Lambda) today (when combined with results from the CMB
and supernova surveys). Further evidence for this cosmological model is
provided by the late-time Integrated Sachs-Wolfe (ISW) effect, which has now
been detected using a variety of tracers of the large scale structure in the
Universe out to redshifts of z>1. The ISW effect also provides an opportunity
to discriminate between Lambda, dynamical dark energy models and the
modification of gravity on large scales.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:25:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nichol",
"Robert C.",
"",
"ICG Portsmouth"
]
] |
0708.2825 | Takashi Ito | K. Ohtsuka, H. Arakida, T. Ito, T. Kasuga, J. Watanabe, D. Kinoshita,
T. Sekiguchi, D. J. Asher, and S. Nakano | Apollo asteroids (1566) Icarus and 2007 MK6: Icarus family members? | 11 pages, 1 figure, to appear on Astrophysical Journal Letters
(journal info added) | null | 10.1086/522589 | null | astro-ph | null | Although it is more complicated to search for near-Earth object (NEO)
families than main belt asteroid (MBA) families, since differential orbital
evolution within a NEO family can cause current orbital elements to drastically
differ from each other, we have found that Apollo asteroids (1566) Icarus and
the newly discovered 2007 MK6 are almost certainly related. Specifically, their
orbital evolutions show a similar profile, time shifted by only ~1000 yr, based
on our time-lag theory. The dynamical relationship between Icarus and 2007 MK6
along with a possible dust band, the Taurid-Perseid meteor swarm, implies the
first detection of an asteroidal NEO family, namely the "Icarus asteroid
family".
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:37:16 GMT"
},
{
"version": "v2",
"created": "Wed, 22 Aug 2007 00:48:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ohtsuka",
"K.",
""
],
[
"Arakida",
"H.",
""
],
[
"Ito",
"T.",
""
],
[
"Kasuga",
"T.",
""
],
[
"Watanabe",
"J.",
""
],
[
"Kinoshita",
"D.",
""
],
[
"Sekiguchi",
"T.",
""
],
[
"Asher",
"D. J.",
""
],
[
"Nakano",
"S.",
""
]
] |
0708.2826 | Jose Riera Prof. | S. Costamagna and J. A. Riera | Magnetic and transport properties of the one-dimensional ferromagnetic
Kondo lattice model with an impurity | 8 pages, 7 figures, to appear in Physical Review B | Phys. Rev. B 77, 045302 (2008) | 10.1103/PhysRevB.77.045302 | null | cond-mat.str-el | null | We have studied the ferromagnetic Kondo lattice model (FKLM) with an Anderson
impurity on finite chains with numerical techniques. We are particularly
interested in the metallic ferromagnetic phase of the FKLM. This model could
describe either a quantum dot coupled to one-dimensional ferromagnetic leads
made with manganites or a substitutional transition metal impurity in a MnO
chain. We determined the region in parameter space where the impurity is empty,
half-filled or doubly-occupied and hence where it is magnetic or nonmagnetic.
The most important result is that we found, for a wide range of impurity
parameters and electron densities where the impurity is magnetic, a singlet
phase located between two saturated ferromagnetic phases which correspond
approximately to the empty and double-occupied impurity states. Transport
properties behave in general as expected as a function of the impurity
occupancy and they provide a test for a recently developed numerical approach
to compute the conductance. The results obtained could be in principle
reproduced experimentally in already existent related nanoscopic devices or in
impurity doped MnO nanotubes.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:39:20 GMT"
},
{
"version": "v2",
"created": "Sun, 2 Dec 2007 00:36:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Costamagna",
"S.",
""
],
[
"Riera",
"J. A.",
""
]
] |
0708.2827 | Dimitris Stamatellos | Dimitris Stamatellos, David Hubber, Anthony Whitworth (School of
Physics & Astronomy, Cardiff University, UK) | Brown dwarf formation by gravitational fragmentation of massive,
extended protostellar discs | 5 pages, accepted for publication in MNRAS Letters | null | 10.1111/j.1745-3933.2007.00383.x | null | astro-ph | null | We suggest that low-mass hydrogen-burning stars like the Sun should sometimes
form with massive extended discs; and we show, by means of radiation
hydrodynamic simulations, that the outer parts of such discs (R>100 AU) are
likely to fragment on a dynamical timescale (10^3 to $10^4 yr), forming
low-mass companions: principally brown dwarfs (BDs), but also very low-mass
hydrogen-burning stars and planetary-mass objects. A few of the BDs formed in
this way remain attached to the primary star, orbiting at large radii. The
majority are released into the field, by interactions amongst themselves; in so
doing they acquire only a low velocity dispersion (<2 km/s), and therefore they
usually retain small discs, capable of registering an infrared excess and
sustaining accretion. Some BDs form close BD/BD binaries, and these binaries
can survive ejection into the field. This BD formation mechanism appears to
avoid some of the problems associated with the `embryo ejection' scenario, and
to answer some of the questions not yet answered by the `turbulent
fragmentation' scenario.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:52:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stamatellos",
"Dimitris",
"",
"School of\n Physics & Astronomy, Cardiff University, UK"
],
[
"Hubber",
"David",
"",
"School of\n Physics & Astronomy, Cardiff University, UK"
],
[
"Whitworth",
"Anthony",
"",
"School of\n Physics & Astronomy, Cardiff University, UK"
]
] |
0708.2828 | Andreas Seeger | Gustavo Garrigos, Andreas Seeger | Characterizations of Hankel multipliers | Final revised version to appear in Mathematische Annalen | Mathematische Annalen, 342, no. 1, Sept. 2008, 31-68. | null | null | math.CA | null | We give characterizations of radial Fourier multipliers as acting on radial
L^p-functions, 1<p<2d/(d+1), in terms of Lebesgue space norms for Fourier
localized pieces of the convolution kernel. This is a special case of
corresponding results for general Hankel multipliers. Besides L^p-L^q bounds we
also characterize weak type inequalities and intermediate inequalities
involving Lorentz spaces. Applications include results on interpolation of
multiplier spaces.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 12:46:16 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Mar 2008 16:38:00 GMT"
}
] | 2010-03-15T00:00:00 | [
[
"Garrigos",
"Gustavo",
""
],
[
"Seeger",
"Andreas",
""
]
] |
0708.2829 | Bert Vercnocke | Antoine Van Proeyen, Bert Vercnocke | Effective action for the field equations of charged black holes | 18 pages, (v2: small corrections, version to be published in CQG) | Class.Quant.Grav.25:035010,2008 | 10.1088/0264-9381/25/3/035010 | KUL-TF-07/13 | hep-th | null | In this article, we consistently reduce the equations of motion for the
bosonic N = 2 supergravity action, using a multi-centered black hole ansatz for
the metric. This reduction is done in a general, non-supersymmetric setup, in
which we extend concepts of BPS black hole technology. First of all we obtain a
more general form of the black hole potential, as part of an effective action
for both the scalars and the vectors in the supergravity theory. Furthermore,
we show that there are extra constraints specifying the solution, which we
calculate explicitly. In the literature, these constraints have already been
studied in the one-center case. We also show that the effective action we
obtain for non-static metrics, can be linked to the "entropy function" for the
spherically symmetric case, as defined by Sen and Cardoso et al.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:14:35 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jan 2008 12:50:20 GMT"
}
] | 2009-12-07T00:00:00 | [
[
"Van Proeyen",
"Antoine",
""
],
[
"Vercnocke",
"Bert",
""
]
] |
0708.2830 | Pawel Danielewicz | Pawel Danielewicz and Jenny Lee (NSCL-MSU) | Symmetry Energy as a Function of Density and Mass | 6 pages, 4 figures, contribution to the VII Latin American Symposium
on Nuclear Physics and Applications, Cusco, Peru, June 11-16, 2007 | AIPConf.Proc.947:301-306,2007 | 10.1063/1.2813821 | null | nucl-th | null | Energy in nuclear matter is, in practice, completely characterized at
different densities and asymmetries, when the density dependencies of symmetry
energy and of energy of symmetric matter are specified. The density dependence
of the symmetry energy at subnormal densities produces mass dependence of
nuclear symmetry coefficient and, thus, can be constrained by that latter
dependence. We deduce values of the mass dependent symmetry coefficients, by
using excitation energies to isobaric analog states. The coefficient
systematic, for intermediate and high masses, is well described in terms of the
symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient
and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond
to the parameter values describing density dependence of symmetry energy, of
L~95 MeV and K_{sym}~25 MeV.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:52:37 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Danielewicz",
"Pawel",
"",
"NSCL-MSU"
],
[
"Lee",
"Jenny",
"",
"NSCL-MSU"
]
] |
0708.2831 | Tariq Shahbaz | T. Shahbaz (IAC) and C.A. Watson (Univ. Sheffield) | The rotational broadening of V395 Car - implications on compact object's
mass | 5 pages, 7 figures, accpeted by AA | null | 10.1051/0004-6361:20078251 | null | astro-ph | null | CONTEXT: The masses previously obtained for the X-ray binary 2S0921-630
inferred a compact object that was either a high-mass neutron star or low-mass
black-hole, but used a previously published value for the rotational broadening
(vsini) with large uncertainties. AIMS: We aim to determine an accurate mass
for the compact object through an improved measurement of the secondary star's
projected equatorial rotational velocity. METHODS: We have used UVES echelle
spectroscopy to determine the vsini of the secondary star (V395 Car) in the
low-mass X-ray binary 2S0921-630 by comparison to an artificially broadened
spectral-type template star. In addition, we have also measured vsini from a
single high signal-to-noise ratio absorption line profile calculated using the
method of Least-Squares Deconvolution (LSD). RESULTS: We determine vsini to lie
between 31.3+/-0.5km/s to 34.7+/-0.5km/s (assuming zero and continuum limb
darkening, respectively) in disagreement with revious results based on
intermediate resolution spectroscopy obtained with the 3.6m NTT. Using our
revised vsini value in combination with the secondary star's radial velocity
gives a binary mass ratio of 0.281+/-0.034. Furthermore, assuming a binary
inclination angle of 75 degrees gives a compact object mass of 1.37+/-0.13Mo.
CONCLUSIONS: We find that using relatively low-resolution spectroscopy can
result in systemic uncertainties in the measured vsini values obtained using
standard methods. We suggest the use of LSD as a secondary, reliable check of
the results as LSD allows one to directly discern the shape of the absorption
line profile. In the light of the new vsini measurement, we have revised down
the compact object's mass, such that it is now compatible with a canonical
neutron star mass.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:08:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Shahbaz",
"T.",
"",
"IAC"
],
[
"Watson",
"C. A.",
"",
"Univ. Sheffield"
]
] |
0708.2832 | Clark Barwick | Clark Barwick | On Reedy Model Categories | 13 pages. Comments sincerely welcomed | null | null | null | math.AT math.CT | null | The sole purpose of this note is to introduce some elementary results on the
structure and functoriality of Reedy model categories. In particular, I give a
very useful little criterion to determine whether composition with a morphism
of Reedy categories determines a left or right Quillen functor. I then give a
number of useful inheritance results.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:18:01 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Barwick",
"Clark",
""
]
] |
0708.2833 | Ted Rogers | J.C. Collins, T.C. Rogers, A.M. Sta\'sto | Fully Unintegrated Parton Correlation Functions and Factorization in
Lowest Order Hard Scattering | 44 pages, 69 figures typos fixed, clarifications and second appendix
added | Phys.Rev.D77:085009,2008 | 10.1103/PhysRevD.77.085009 | null | hep-ph | null | Motivated by the need to correct the potentially large kinematic errors in
approximations used in the standard formulation of perturbative QCD, we
reformulate deeply inelastic lepton-proton scattering in terms of gauge
invariant, universal parton correlation functions which depend on all
components of parton four-momentum. Currently, different hard QCD processes are
described by very different perturbative formalisms, each relying on its own
set of kinematical approximations. In this paper we show how to set up
formalism that avoids approximations on final-state momenta, and thus has a
very general domain of applicability. The use of exact kinematics introduces a
number of significant conceptual shifts already at leading order, and tightly
constrains the formalism. We show how to define parton correlation functions
that generalize the concepts of parton density, fragmentation function, and
soft factor. After setting up a general subtraction formalism, we obtain a
factorization theorem. To avoid complications with Ward identities the full
derivation is restricted to abelian gauge theories; even so the resulting
structure is highly suggestive of a similar treatment for non-abelian gauge
theories.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:11:46 GMT"
},
{
"version": "v2",
"created": "Thu, 1 May 2008 21:02:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Collins",
"J. C.",
""
],
[
"Rogers",
"T. C.",
""
],
[
"Staśto",
"A. M.",
""
]
] |
0708.2834 | Samuel Baltazar | Samuel E. Baltazar, Mario De Menech, Ulf Saalmann, Aldo H. Romero and
Martin E. Garcia | Negative differential resistance of Styrene on an ideal Si[111] surface:
dependence of the I-V characteristics on geometry, surface doping and shape
of the STM-tip | 20 pages, 13 figures | null | null | null | cond-mat.mtrl-sci | null | We study the electron transport properties through a supported organic
molecule styrene (C8H8) on an ideal silicon surface Si[111] and probed by a
STM-tip. The I-V characteristics and the differential conductance of the
molecule are calculated using a self consistent approach based on non
equilibrium Green's functions. Two different adsorption configurations for the
molecule on the surface were considered which corresponds to a global and a
local minimum of the total energy. In both cases we find a negative
differential resistance (NDR) in a given interval of bias voltages. This effect
is controlled by the states available close to the Fermi level of the surface
and can be manipulated by properly doping the substrate. We also analyze the
influence of the tip-shape on the I-V characteristics.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 19:50:31 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Baltazar",
"Samuel E.",
""
],
[
"De Menech",
"Mario",
""
],
[
"Saalmann",
"Ulf",
""
],
[
"Romero",
"Aldo H.",
""
],
[
"Garcia",
"Martin E.",
""
]
] |
0708.2835 | Gautam Bhattacharyya | Gautam Bhattacharyya, Debajyoti Choudhury, Dilip Kumar Ghosh | Unraveling unparticles through violation of atomic parity and rare
beauty | 11 pages, 3 figures; v2: minor typos settled, to appear in Phys Lett
B; v3: minor changes in discussions following Eq.(8), matches PLB version | Phys.Lett.B655:261-268,2007 | 10.1016/j.physletb.2007.09.044 | SINP/TNP/07-25 | hep-ph | null | We put constraints on unparticle physics, specifically on the scale
$\Lambda_\U$ and the scale dimension $d_\U$ of unparticle operators, using (i)
measurements of atomic parity violation as well as (ii) branching ratio and CP
asymmetry measurements in some rare non-leptonic B decay channels.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:21:34 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Sep 2007 13:59:58 GMT"
},
{
"version": "v3",
"created": "Mon, 8 Oct 2007 09:58:34 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bhattacharyya",
"Gautam",
""
],
[
"Choudhury",
"Debajyoti",
""
],
[
"Ghosh",
"Dilip Kumar",
""
]
] |
0708.2836 | Elias Brinks Dr | Elias Brinks, Fabian Walter and Evan D. Skillman | Free-Floating HI Clouds in the M 81 Group | To appear in the Proceedings of IAU Symp. 244 on "Dark Galaxies and
Lost Baryons", eds. J. I. Davies & M. J. Disney | null | 10.1017/S1743921307013907 | null | astro-ph | null | Recent VLA observations pointed at dwarf spheroidal (dSph) galaxies in the M
81 group reveal a hitherto hidden population of extremely low mass (~1e5 Msol)
HI clouds with no obvious optical counterparts. We have searched 10 fields in
the M81 group totalling 2.2 square degree, both targeting known dwarf
spheroidal galaxies and blank fields around the central triplet. Our
observations show that the new population of low-mass HI clouds appears to be
confined to a region toward the South-East of the central triplet (at distances
of ~100 kpc from M 81). Possible explanations for these free-floating HI clouds
are that they are related to the dSphs found to the South-East of M 81, that
they belong to the galaxies of the M 81 triplet (equivalent to HVCs), that they
are of primordial nature and provide fresh, unenriched material falling into
the M 81 group, or that they are tidal debris from the 3-body interaction
involving M 81-M 82-NGC 3077. Based on circumstantial evidence, we currently
favour the latter explanation.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:22:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Brinks",
"Elias",
""
],
[
"Walter",
"Fabian",
""
],
[
"Skillman",
"Evan D.",
""
]
] |
0708.2837 | Alexander Bais | F. Alexander Bais and J. Doyne Farmer | The Physics of Information | The paper has 65 pages and 9 figures. It is a contribution to "The
handbook on the philosophy of information", edited by J. van Benthem and P.
Adriaans, to be published by Elsevier. In this revised version, we added
references, corrected typos and made some improvements in the text | null | null | ITFA-2007-37 and SFI Working paper | physics.class-ph cond-mat.stat-mech gr-qc physics.gen-ph quant-ph | null | We review of the interface between (theoretical) physics and information for
non-experts. The origin of information as related to the notion of entropy is
described, first in the context of thermodynamics then in the context of
statistical mechanics. A close examination of the foundations of statistical
mechanics and the need to reconcile the probabilistic and deterministic views
of the world leads us to a discussion of chaotic dynamics, where information
plays a crucial role in quantifying predictability. We then discuss a variety
of fundamental issues that emerge in defining information and how one must
exercise care in discussing concepts such as order, disorder, and incomplete
knowledge. We also discuss an alternative form of entropy and its possible
relevance for nonequilibrium thermodynamics.
In the final part of the paper we discuss how quantum mechanics gives rise to
the very different concept of quantum information. Entirely new possibilities
for information storage and computation are possible due to the massive
parallel processing inherent in quantum mechanics. We also point out how
entropy can be extended to apply to quantum mechanics to provide a useful
measurement for quantum entanglement.
Finally we make a small excursion to the interface betweeen quantum theory
and general relativity, where one is confronted with an "ultimate information
paradox" posed by the physics of Black Holes.
In this review we have limited ourselves; not all relevant topics that touch
on physics and information could be covered.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:22:43 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Dec 2007 13:28:13 GMT"
}
] | 2007-12-18T00:00:00 | [
[
"Bais",
"F. Alexander",
""
],
[
"Farmer",
"J. Doyne",
""
]
] |
0708.2838 | Jaka Smrekar | Jaka Smrekar | CW type of inverse limits and function spaces | null | null | null | null | math.AT | null | Given CW complexes X and Y, let map(X,Y) denote the space of continuous
functions from X to Y with the compact open topology. The space map(X,Y) need
not have the homotopy type of a CW complex. Here the results of an extensive
investigation of various necessary and various sufficient conditions for
map(X,Y) to have the homotopy type of a CW complex are exhibited. The results
extend all previously known results on this topic. Moreover, appropriate
converses are given for the previously known sufficient conditions.
It is shown that this difficult question is related to well known problems in
algebraic topology. For example, the geometric Moore conjecture (asserting that
a simply connected finite complex admits an eventual geometric exponent at any
prime if and only if it is elliptic) can be restated in terms of CW homotopy
type of certain function spaces.
Spaces of maps between CW complexes are a particular case of inverse limits
of systems whose bonds are Hurewicz fibrations between spaces of CW homotopy
type. Related problems concerning CW homotopy type of the limit space of such a
system are also studied. In particular, an almost complete solution to a well
known problem concerning towers of fibrations is presented.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:23:27 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Smrekar",
"Jaka",
""
]
] |
0708.2839 | Oren Bergman Dr. | Oren Bergman, Shigenori Seki, Jacob Sonnenschein | Quark mass and condensate in HQCD | 23 pages, 7 figures; v2: corrected typos in eqs. (4.3), (4.4), (4.5),
(4.9) and (4.11), and corrected figures 3, 4, 5 and 6; v3: section 5.3 on the
pion mass rewritten in a clearer way, version published in JHEP | JHEP0712:037,2007 | 10.1088/1126-6708/2007/12/037 | TAUP-2802/07 | hep-th hep-ph | null | We extend the Sakai-Sugimoto holographic model of QCD (HQCD) by including the
scalar bi-fundamental "tachyon" field in the 8-brane-anti-8-brane probe theory.
We show that this field is responsible both for the spontaneous breaking of the
chiral symmetry, and for the generation of (current algebra) quark masses, from
the point of view of the bulk theory. As a by-product we show how this leads to
the Gell-Mann- Oakes-Renner relation for the pion mass.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:27:27 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Sep 2007 15:03:33 GMT"
},
{
"version": "v3",
"created": "Tue, 11 Dec 2007 18:32:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bergman",
"Oren",
""
],
[
"Seki",
"Shigenori",
""
],
[
"Sonnenschein",
"Jacob",
""
]
] |
0708.2840 | Natalia Pavlenko | Natalia Pavlenko | CO-activator model for reconstructing Pt(100) surfaces: local
microstructures and chemical turbulence | 11 pages, 11 figures, to appear in Physical Review E | Phys. Rev. E 77, 026203 (2008) | 10.1103/PhysRevE.77.026203 | null | cond-mat.stat-mech cond-mat.mtrl-sci | null | We present the results of the modelling of CO adsorption and catalytic CO
oxidation on inhomogeneous Pt(100) surfaces which contain structurally
different areas. These areas are formed during the CO-induced transition from a
reconstructed phase with hexagonal geometry of the overlayer to a bulk-like
(1x1) phase with square atomic arrangement. In the present approach, the
surface transition is explained in terms of nonequilibrium bistable behavior.
The bistable region is characterized by a coexistence of the hexagonal and
(1x1) phases and is terminated in a critical bifurcation point which is located
at (T_c ~680 K, p_CO ~10 Torr). Due to increasing fluctuations, the behavior at
high temperatures and pressures in the vicinity of this cusp point should be
qualitatively different from the hysteresis-type behavior which is typically
observed in the experiments under ultrahigh vacuum conditions. On the
inhomogeneous surface, we find a regime of nonuniform oscillations
characterized by random standing waves of adsorbate concentrations. The
resulting spatial deformations of wave fronts allow to gain deeper insight into
the nature of irregular oscillations on Pt(100) surface.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:30:04 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Jan 2008 06:53:56 GMT"
}
] | 2008-02-09T00:00:00 | [
[
"Pavlenko",
"Natalia",
""
]
] |
0708.2841 | Ragab Gad | Ragab M. Gad | Geodesics and Geodesic Deviation in static Charged Black Holes | 12 pages, 5 figures, small changes, figures and references added,
conclusions changed. A improved, version accepted in Astrophysics and Space
Science | Astrophys.Space Sci.330:107-114,2010 | 10.1007/s10509-010-0359-1 | null | math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The radial motion along null geodesics in static charged black hole
space-times, in particular, the Reissner-Nordstr\"om and stringy charged black
holes are studied. We analyzed the properties of the effective potential. The
circular photon orbits in these space-times are investigated. We found that the
radius of circular photon orbits in both charged black holes are different and
differ from that given in Schwarzschild space-time. We studied the physical
effects of the gravitational field between two test particles in stringy
charged black hole and compared the results with that given in Schwarzschild
and Reissner-Nordstr\"om black holes.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:35:51 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Apr 2009 12:12:21 GMT"
},
{
"version": "v3",
"created": "Wed, 3 Mar 2010 16:48:14 GMT"
}
] | 2015-02-06T00:00:00 | [
[
"Gad",
"Ragab M.",
""
]
] |
0708.2842 | Dimitri Alexei Gadotti | Dimitri Alexei Gadotti (Max Planck Institute for Astrophysics) | The Structural Parameters of Bulges, Bars and Discs in the Local
Universe | 4 pages, 3 figures; contributed talk to appear in "Formation and
Evolution of Galaxy Bulges", proceedings of the IAU Symp. 245, held in
Oxford, UK, July 2007, M. Bureau, E. Athanassoula, B. Barbuy (eds.) | null | 10.1017/S1743921308017420 | null | astro-ph | null | Image decomposition of galaxies is now routinely used to estimate the
structural parameters of galactic components. In this work, I address questions
on the reliability of this technique. In particular, do bars and AGN need to be
taken into account to obtain the structural parameters of bulges and discs? And
to what extent can we trust image decomposition when the physical spatial
resolution is relatively poor? With this aim, I performed multi-component
(bar/bulge/disc/AGN) image decomposition of a sample of very nearby galaxies
and their artificially redshifted images, and verified the effects of removing
the bar and AGN components from the models. Neglecting bars can result in a
overestimation of the bulge-to-total luminosity ratio of a factor of two, even
if the resolution is low. Similar effects result when bright AGN are not
considered in the models, but only when the resolution is high. I also show
that the structural parameters of more distant galaxies can in general be
reliably retrieved, at least up to the point where the physical spatial
resolution is about 1.5 Kpc, but bulge parameters are prone to errors if its
effective radius is small compared to the seeing radius, and might suffer from
systematic effects. I briefly discuss the consequences of these results to our
knowledge of the stellar mass budget in the local universe, and finish by
showing preliminary results from a large SDSS sample on the dichotomy between
classical and pseudo-bulges.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:38:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gadotti",
"Dimitri Alexei",
"",
"Max Planck Institute for Astrophysics"
]
] |
0708.2843 | Roger Colbeck | Roger Colbeck | The Impossibility Of Secure Two-Party Classical Computation | 10 pages | Physical Review A 76, 062308 (2007) | 10.1103/PhysRevA.76.062308 | null | quant-ph cs.CR | null | We present attacks that show that unconditionally secure two-party classical
computation is impossible for many classes of function. Our analysis applies to
both quantum and relativistic protocols. We illustrate our results by showing
the impossibility of oblivious transfer.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:52:45 GMT"
},
{
"version": "v2",
"created": "Fri, 14 Dec 2007 08:59:41 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Colbeck",
"Roger",
""
]
] |
0708.2844 | Arsen G. Khachatryan | A. G. Khachatryan, A. Irman, F. A. van Goor, K.-J. Boller | Dynamics of Femtosecond Electron Bunches | 34 pages, incl. 11 figs. and 1 table, submitted for publication | null | null | null | physics.plasm-ph physics.acc-ph | null | In the laser wakefield accelerator (LWFA) a short intense laser pulse, with a
duration of the order of a plasma wave period, excites an unusually strong
plasma wake wave (laser wakefield). Recent experiments on laser wakefield
acceleration [Nature (London) 431, p.535, p.538, p.541 (2004)] demonstrated
generation of ultra-short (with a duration of a few femtoseconds) relativistic
electron bunches with relatively low energy spread of the order of a few
percent. We have studied the dynamics of such bunches in vacuum and in laser
wakefield. The results show strong bunch dynamics already on a few millimeters
propagation distance in both cases. In vacuum, the bunch radius and emittance
quickly grow. The latter worsens the focusability of the bunch. We found that
when a femtosecond bunch is accelerated in a channel-guided laser wakefield,
for realistic bunch lengths, the bunch length is approximately conserved.
However, the spread in betatron frequencies leads to fast betatron phase mixing
in the bunch envelope for on-axis injection. When bunch is injected in a laser
wakefield off-axis, the bunch decoherence results in considerable increase in
the normalized bunch emittance, and, in some cases, in increase in the energy
spread, after acceleration. We also discuss a possible two-stage laser
wakefield accelerator.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:51:45 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Khachatryan",
"A. G.",
""
],
[
"Irman",
"A.",
""
],
[
"van Goor",
"F. A.",
""
],
[
"Boller",
"K. -J.",
""
]
] |
0708.2845 | Stephan Falke | C. Klempt, T. Henninger, O. Topic, J. Will, St. Falke, W. Ertmer, and
J. Arlt | Transport of a quantum degenerate heteronuclear Bose-Fermi mixture in a
harmonic trap | 7 pages, 8 figures | Eur. Phys. J. D 48, 121 (2008) | 10.1140/epjd/e2008-00067-5 | null | cond-mat.other | null | We report on the transport of mixed quantum degenerate gases of bosonic 87Rb
and fermionic 40K in a harmonic potential provided by a modified QUIC trap. The
samples are transported over a distance of 6 mm to the geometric center of the
anti-Helmholtz coils of the QUIC trap. This transport mechanism was implemented
by a small modification of the QUIC trap and is free of losses and heating. It
allows all experiments using QUIC traps to use the highly homogeneous magnetic
fields that can be created in the center of a QUIC trap and improves the
optical access to the atoms, e.g., for experiments with optical lattices. This
mechanism may be cascaded to cover even larger distances for applications with
quantum degenerate samples.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 13:54:35 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Mar 2008 10:31:28 GMT"
}
] | 2010-12-22T00:00:00 | [
[
"Klempt",
"C.",
""
],
[
"Henninger",
"T.",
""
],
[
"Topic",
"O.",
""
],
[
"Will",
"J.",
""
],
[
"Falke",
"St.",
""
],
[
"Ertmer",
"W.",
""
],
[
"Arlt",
"J.",
""
]
] |
0708.2846 | Norma Mankoc Borstnik | G. Bregar, M. Breskvar, D. Lukman, N.S. Mankoc Borstnik | On the origin of families of quarks and leptons - predictions for four
families | 31 pages,revtex | NewJ.Phys.10:093002,2008 | 10.1088/1367-2630/10/9/093002 | null | hep-ph | null | The approach unifying all the internal degrees of freedom--proposed by one of
us--is offering a new way of understanding families of quarks and leptons: A
part of the starting Lagrange density in d(=1+13), which includes two kinds of
spin connection fields--the gauge fields of two types of Clifford algebra
objects--transforms the right handed quarks and leptons into the left handed
ones manifesting in d=1+3 the Yukawa couplings of the Standard model. We study
the influence of the way of breaking symmetries on the Yukawa couplings and
estimate properties of the fourth family--the quark masses and the mixing
matrix, investigating the possibility that the fourth family of quarks and
leptons appears at low enough energies to be observable with the new generation
of accelerators.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 14:00:23 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bregar",
"G.",
""
],
[
"Breskvar",
"M.",
""
],
[
"Lukman",
"D.",
""
],
[
"Borstnik",
"N. S. Mankoc",
""
]
] |
0708.2847 | Philip Massey | Philip Massey, Bertrand Plez, Emily M. Levesque, K. A. G. Olsen, David
R. Silva, Geoffery C. Clayton | Physical Properties of Red Supergiants | To appear in "The Biggest, Baddest, Coolest Stars" (ASP Conf
proceeding), ed. D. Luttermoser, B. Smith, and R. Stencel | null | null | null | astro-ph | null | Red supergiants (RSGs) are an evolved stage in the life of intermediate
massive stars (<25Mo). For many years their location in the H-R diagram was at
variance with the evolutionary models. Using the MARCS stellar atmosphere
models, we have determined new effective temperatures and bolometric
luminosities for RSGs in the Milky Way, LMC, and SMC, and our work has resulted
in much better agreement with the evolutionary models. We have also found
evidence of significant visual extinction due to circumstellar dust. Although
in the Milky Way the RSGs contribute only a small fraction (<1%) of the dust to
the interstellar medium (ISM), in starburst galaxies or galaxies at large
look-back times, we expect that RSGs may be the main dust source. We are in the
process of extending this work now to RSGs of higher and lower metallicities
using the galaxies M31 and WLM.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 14:00:57 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Massey",
"Philip",
""
],
[
"Plez",
"Bertrand",
""
],
[
"Levesque",
"Emily M.",
""
],
[
"Olsen",
"K. A. G.",
""
],
[
"Silva",
"David R.",
""
],
[
"Clayton",
"Geoffery C.",
""
]
] |
0708.2848 | Katherine J. Inskip | K.J. Inskip, C.N. Tadhunter, D. Dicken, J. Holt, M. Villar-Martin, R.
Morganti | PKS1932-46: a radio source in an interacting group? | 15 pages, 14 figures (compressed for astro-ph, 1 colour). Accepted
for publication in MNRAS. Abstract abridged | null | 10.1111/j.1365-2966.2007.12378.x | null | astro-ph | null | We present the results of a multiwavelength study of the z=0.23 radio source
PKS1932-46. VIMOS IFU spectroscopy is used to study the morphology, kinematics
and ionisation state of the EELR surrounding this source, and also a companion
galaxy at a similar redshift. Near- and far-IR imaging observations obtained
using the NTT and SPITZER are used to analyse the underlying galaxy
morphologies and the nature of the AGN. The host galaxy is identified as an ~M*
elliptical. Combining Spitzer mid-IR with X-ray, optical and near-IR imaging
observations of this source, we conclude that its AGN is underluminous for a
radio source of this type, despite its status as a BLRG. However, given its
relatively large [OIII] luminosity it is likely that the AGN was substantially
more luminous in the recent past (<10^4 years ago). The EELR is remarkably
extensive and complex, reminiscent of the systems observed around sources at
higher redshifts/radio powers, and the gas is predominantly ionised by a
mixture of AGN photoionisation and emission from young stars. We confirm the
presence of a series of star-forming knots extending N-S from the host galaxy,
with more prodigious star formation occuring in the merging companion galaxy to
the northeast, which has sufficient luminosity at mid- to far-IR wavelengths to
be classified as a LIRG. The most plausible explanation of our observations is
that PKS1932-46 is a member of an interacting galaxy group, and that the
impressive EELR is populated by star-forming, tidal debris. We suggest that the
AGN itself may currently be fuelled by material associated either with the
current interaction, or with a previous merger event. Surprisingly, it is the
companion object, rather than the radio source host galaxy, which is undergoing
the bulk of the star formation activity within the group.
| [
{
"version": "v1",
"created": "Tue, 21 Aug 2007 14:02:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Inskip",
"K. J.",
""
],
[
"Tadhunter",
"C. N.",
""
],
[
"Dicken",
"D.",
""
],
[
"Holt",
"J.",
""
],
[
"Villar-Martin",
"M.",
""
],
[
"Morganti",
"R.",
""
]
] |
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