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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0705.2698 | Ali Mohammad-Djafari | Ali Mohammad-Djafari | Computed tomography image reconstruction from only two projections | 8 pages. There is also a French language version | null | null | null | physics.data-an physics.comp-ph | null | English: This paper concerns the image reconstruction from a few projections
in Computed Tomography (CT). The main objective of this paper is to show that
the problem is so ill posed that no classical method, such as analytical
methods based on inverse Radon transform, nor the algebraic methods such as
Least squares (LS) or regularization theory can give satisfactory result. As an
example, we consider in detail the case of image reconstruction from two
horizontal and vertical projections. We then show how a particular composite
Markov modeling and the Bayesian estimation framework can possibly propose
satisfactory solutions to the problem. For demonstration and educational
purpose a set of Matlab programs are given for a live presentation of the
results.
-----
French: Ce travail, \`a but p\'edagogique, pr\'esente le probl\`eme inverse
de la reconstruction d'image en tomographie X lorsque le nombre des projections
est tr\`es limit\'e. voir le texte en Anglais et en Fran\c{c}ais.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 13:27:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mohammad-Djafari",
"Ali",
""
]
] |
0705.2699 | Anthony Csizmazia | Anthony Csizmazia | On the Riemann zeta-function, Part II | 43 pages. PDF file | null | null | null | math.GM | null | An odd meromorphic function f(s) is constructed from the Riemann
zeta-function evaluated at one-half plus s. We determine the two-sided Laplace
transform representation of f(s) on open vertical strips, V'(4w), disjoint from
the (translated) critical strip. V'(4w) consists of all s with real part,
Re(s), of absolute value greater than one-half and Re(s) between successive
poles 4w, 4(w + 1) of f(s), with w an integer. The corresponding Laplace
density is related to confluent hypergeometric functions. That density is shown
to be positive for nonzero w other than -1. Those results are obtained without
relying on any unproven hypothesis. They are used together with the Riemann
hypothesis and hypotheses advanced by the author to obtain conditional results
concerning the zeta-function. Those results are presented in Part I. Their
proofs are derived in Parts III-V. A metric geometry expression of the
positivity of the Laplace densities arising is established in Part VI.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 13:43:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Csizmazia",
"Anthony",
""
]
] |
0705.2700 | Sergei Chekanov V. | S. Chekanov (for the ZEUS Collaboration) | Prompt photons with associated jets in photoproduction at HERA | Proceedings of the XV International Workshop on Deep Inelastic
Scattering (DIS07 April 16-20, 2007, Munich, Germany) | null | null | null | hep-ex | null | Prompt photons, together with an accompanying jet, have been studied in the
photoproduction regime of ep scattering with the ZEUS detector at HERA.
Predictions based on leading-logarithm parton-shower Monte Carlo models and
next-to-leading-order (NLO) QCD underestimate the gamma+jet cross sections for
transverse energies of prompt photons below 7 GeV, while the kT-factorisation
QCD calculation agrees with the data in this region.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 13:44:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chekanov",
"S.",
"",
"for the ZEUS Collaboration"
]
] |
0705.2701 | Philippe Soulier | Meng-Chen Hsieh, Clifford M. Hurvich (IOMS), Philippe Soulier
(MODAL'X) | Asymptotics for Duration-Driven Long Range Dependent Processes | null | Journal of Econometrics Volume 141, Issue 2, December 2007, Pages
913-949 | 10.1016/j.jeconom.2006.12.001 | null | math.ST stat.TH | null | We consider processes with second order long range dependence resulting from
heavy tailed durations. We refer to this phenomenon as duration-driven long
range dependence (DDLRD), as opposed to the more widely studied linear long
range dependence based on fractional differencing of an $iid$ process. We
consider in detail two specific processes having DDLRD, originally presented in
Taqqu and Levy (1986), and Parke (1999). For these processes, we obtain the
limiting distribution of suitably standardized discrete Fourier transforms
(DFTs) and sample autocovariances. At low frequencies, the standardized DFTs
converge to a stable law, as do the standardized sample autocovariances at
fixed lags. Finite collections of standardized sample autocovariances at a
fixed set of lags converge to a degenerate distribution. The standardized DFTs
at high frequencies converge to a Gaussian law. Our asymptotic results are
strikingly similar for the two DDLRD processes studied. We calibrate our
asymptotic results with a simulation study which also investigates the
properties of the semiparametric log periodogram regression estimator of the
memory parameter.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 13:47:49 GMT"
}
] | 2012-09-19T00:00:00 | [
[
"Hsieh",
"Meng-Chen",
"",
"IOMS"
],
[
"Hurvich",
"Clifford M.",
"",
"IOMS"
],
[
"Soulier",
"Philippe",
"",
"MODAL'X"
]
] |
0705.2702 | Andrew Duff | Andrew I. Duff and James F. Annett | Variational QMC study of a Hydrogen atom in jellium with comparison to
LSDA and LSDA-SIC solutions | 16 pages, 9 Postscript figures | null | 10.1103/PhysRevB.76.115113 | null | cond-mat.str-el | null | A Hydrogen atom immersed in a finite jellium sphere is solved using
variational quantum Monte Carlo (VQMC). The same system is also solved using
density functional theory (DFT), in both the local spin density (LSDA) and
self-interaction correction (SIC) approximations. The immersion energies
calculated using these methods, as functions of the background density of the
jellium, are found to lie within 1eV of each other with minima in approximately
the same positions. The DFT results show overbinding relative to the VQMC
result. The immersion energies also suggest an improved performance of the SIC
over the LSDA relative to the VQMC results. The atom-induced density is also
calculated and shows a difference between the methods, with a more extended
Friedel oscillation in the case of the VQMC result.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:38:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Duff",
"Andrew I.",
""
],
[
"Annett",
"James F.",
""
]
] |
0705.2703 | Juan B. Gil | Juan B. Gil, Thomas Krainer, Gerardo A. Mendoza | A conic manifold perspective of elliptic operators on graphs | 18 pages | J. Math. Anal. Appl. 340 (2008), no. 2, 1296-1311 | 10.1016/j.jmaa.2007.09.049 | null | math.AP math.FA math.SP | null | We give a simple, explicit, sufficient condition for the existence of a
sector of minimal growth for second order regular singular differential
operators on graphs. We specifically consider operators with a singular
potential of Coulomb type and base our analysis on the theory of elliptic cone
operators.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:01:56 GMT"
}
] | 2023-10-24T00:00:00 | [
[
"Gil",
"Juan B.",
""
],
[
"Krainer",
"Thomas",
""
],
[
"Mendoza",
"Gerardo A.",
""
]
] |
0705.2704 | Danielle Rojas-Rousse | Auguste Ndoutoume, Danielle Rousse (IRBII), Roland Allemand | Rythmes d'activit\'e locomotrice chez deux insectes parasito\"ides
sympatriques : Eupelmus orientalis et Eupelmus vuilleti (Hym\'enopt\`ere,
Eupelmidae) | null | Comptes Rendus Biologies 329 (2006) 476-482 | null | null | q-bio.PE | null | With an automatic image analysis device, we studied the temporal distribution
of the locomotor activity of E. orientalis and E. vuilleti during 24 h, and
over several days to know whether the activity rhythms of these two Eupelmidae
play a role in their competitive interactions. The analysis of locomotor
activity rhythms of E. orientalis and E. vuilleti shows that the locomotor
activity of both species presents daily cyclic variations. These two Eupelmidae
have similar activity rhythms. Displacements of these parasitoids essentially
take place during the photophase. But the activity of E. vuilleti is earlier,
because the individuals of this species start their activity on average 4 to 5
h earlier than those of E. orientalis. E. vuilleti begins its displacements
several hours before the onset of lighting, whereas E. orientalis is active
only in the presence of the light. This shift of starting activity is thus a
factor allowing these concurrent species to minimize their interactions during
the cohabitation period in traditional granaries after the harvests of cowpea.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:36:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ndoutoume",
"Auguste",
"",
"IRBII"
],
[
"Rousse",
"Danielle",
"",
"IRBII"
],
[
"Allemand",
"Roland",
""
]
] |
0705.2705 | Vasile Topor Pop N | V. Topor Pop, J. Barrette, C. Gale, S. Jeon (McGill Univ., Canada), M.
Gyulassy (Columbia Univ.NY, USA and FIAS, Frankfurt am Main, Germany) | (Multi)Strangeness Production in Pb+Pb collisions at LHC. HIJING/BBar
v2.0 predictions | Comments: 3 pages, 2 figures, submitted to the CERN Theory Institute
Workshop, Heavy Ion Collisions at the LHC. Last Call Predictions, May 14 -
June 8, 2007 | null | null | null | hep-ph | null | Strangeness and multi-strangeness particles production can be used to explore
the initial transient field fluctuations in heavy ion collisions. We emphasize
the role played by Junction anti-Junction (JJbar) loops and strong color
electric fields (SCF) in these collisions. Transient field fluctuations of SCF
on the baryon production in central (0-5%) Pb+Pb collisions at nucleon-nucleon
centre of mass energy of 5.5 TeV will be discussed in the framework of
HIJING/BBbar v2.0 model, looking in particular to the predicted evolution of
nuclear modification factors R_AA from RHIC to LHC energies. Our results
indicate the importance of a good description of the baseline elementary p+p
collisions at this energy.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:04:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pop",
"V. Topor",
"",
"McGill Univ., Canada"
],
[
"Barrette",
"J.",
"",
"McGill Univ., Canada"
],
[
"Gale",
"C.",
"",
"McGill Univ., Canada"
],
[
"Jeon",
"S.",
"",
"McGill Univ., Canada"
],
[
"Gyulassy",
"M.",
"",
"Columbia Univ.NY, USA and FIAS, Frankfurt am Main, Germany"
]
] |
0705.2706 | Massimo Sandal | Francesco Valle, Massimo Sandal, Bruno Samor\'i | The Interplay between Chemistry and Mechanics in the Transduction of a
Mechanical Signal into a Biochemical Function | 50 pages, 18 figures | null | 10.1016/j.plrev.2007.06.001 | null | q-bio.BM q-bio.MN | null | There are many processes in biology in which mechanical forces are generated.
Force-bearing networks can transduce locally developed mechanical signals very
extensively over different parts of the cell or tissues. In this article we
conduct an overview of this kind of mechanical transduction, focusing in
particular on the multiple layers of complexity displayed by the mechanisms
that control and trigger the conversion of a mechanical signal into a
biochemical function. Single molecule methodologies, through their capability
to introduce the force in studies of biological processes in which mechanical
stresses are developed, are unveiling subtle intertwining mechanisms between
chemistry and mechanics and in particular are revealing how chemistry can
control mechanics. The possibility that chemistry interplays with mechanics
should be always considered in biochemical studies.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:11:02 GMT"
},
{
"version": "v2",
"created": "Wed, 23 May 2007 13:26:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Valle",
"Francesco",
""
],
[
"Sandal",
"Massimo",
""
],
[
"Samorí",
"Bruno",
""
]
] |
0705.2707 | Z. C. Tu | Z. C. Tu and U. Seifert | Concise theory of chiral lipid membranes | 14 pages, 7 figures | Phys. Rev. E 76, 031603 (2007) | 10.1103/PhysRevE.76.031603 | null | cond-mat.soft math-ph math.MP physics.bio-ph | null | A theory of chiral lipid membranes is proposed on the basis of a concise free
energy density which includes the contributions of the bending and the surface
tension of membranes, as well as the chirality and orientational variation of
tilting molecules. This theory is consistent with the previous experiments
[J.M. Schnur \textit{et al.}, Science \textbf{264}, 945 (1994); M.S. Spector
\textit{et al.}, Langmuir \textbf{14}, 3493 (1998); Y. Zhao, \textit{et al.},
Proc. Natl. Acad. Sci. USA \textbf{102}, 7438 (2005)] on self-assembled chiral
lipid membranes of DC$_{8,9}$PC. A torus with the ratio between its two
generated radii larger than $\sqrt{2}$ is predicted from the Euler-Lagrange
equations. It is found that tubules with helically modulated tilting state are
not admitted by the Euler-Lagrange equations, and that they are less
energetically favorable than helical ripples in tubules. The pitch angles of
helical ripples are theoretically estimated to be about 0$^\circ$ and
35$^\circ$, which are close to the most frequent values 5$^\circ$ and
28$^\circ$ observed in the experiment [N. Mahajan \textit{et al.}, Langmuir
\textbf{22}, 1973 (2006)]. Additionally, the present theory can explain twisted
ribbons of achiral cationic amphiphiles interacting with chiral tartrate
counterions. The ratio between the width and pitch of twisted ribbons is
predicted to be proportional to the relative concentration difference of left-
and right-handed enantiomers in the low relative concentration difference
region, which is in good agreement with the experiment [R. Oda \textit{et al.},
Nature (London) \textbf{399}, 566 (1999)].
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:21:42 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 04:55:27 GMT"
}
] | 2007-09-27T00:00:00 | [
[
"Tu",
"Z. C.",
""
],
[
"Seifert",
"U.",
""
]
] |
0705.2708 | Fridolin Weber | F. Weber (San Diego State University), R. Negreiros (San Diego State
University), and P. Rosenfield (San Diego State University) | Neutron Star Interiors and the Equation of State of Superdense Matter | 33 pages, 20 figures; Invited review talk presented at "Neutron Stars
and Pulsars: About 40 years after the discovery," Physics Center Bad Honnef,
Germany, 14-19 May 2006. To be published in Springer Lecture Notes | null | null | null | astro-ph nucl-th | null | Neutron stars contain matter in one of the densest forms found in the
Universe. This feature, together with the unprecedented progress in
observational astrophysics, makes such stars superb astrophysical laboratories
for a broad range of exciting physical studies. This paper gives an overview of
the phases of dense matter predicted to make their appearance in the cores of
neutron stars. Particular emphasis is put on the role of strangeness. Net
strangeness is carried by hyperons, K-mesons, H-dibaryons, and strange quark
matter, and may leave its mark in the masses, radii, moment of inertia,
dragging of local inertial frames, cooling behavior, surface composition, and
the spin evolution of neutron stars. These observables play a key role for the
exploration of the phase diagram of dense nuclear matter at high baryon number
density but low temperature, which is not accessible to relativistic heavy ion
collision experiments.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:25:02 GMT"
},
{
"version": "v2",
"created": "Sat, 19 May 2007 01:50:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Weber",
"F.",
"",
"San Diego State University"
],
[
"Negreiros",
"R.",
"",
"San Diego State\n University"
],
[
"Rosenfield",
"P.",
"",
"San Diego State University"
]
] |
0705.2709 | Iris Rottlaender | Iris Rottlaender (University of Bonn, on behalf of the ATLAS
collaboration) | Prospects for the search for Higgs bosons with vector boson fusion
processes at the LHC | 4 pages, 6 figures, To appear in the proceedings of the 42nd
Rencontres de Moriond on QCD and High-Energy Hadronic Interactions, La
Thuile, March 2007 | null | null | null | hep-ph | null | The search for the Higgs boson is one of the main physics goals of the Large
Hadron Collider (LHC) and its two multi-purpose experiments, ATLAS and CMS.
Vector boson fusion is the second largest production process for a standard
model Higgs boson at the LHC and offers excellent means for background
suppression. This paper gives an overview of the prospects of Higgs boson
searches using vector boson fusion at the LHC. For a standard model Higgs
boson, the decay channels H->tautau, H->WW and H->gammagamma are discussed. The
discovery potential in the framework of the MSSM is summarized.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:27:18 GMT"
},
{
"version": "v2",
"created": "Sun, 20 May 2007 11:45:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rottlaender",
"Iris",
"",
"University of Bonn, on behalf of the ATLAS\n collaboration"
]
] |
0705.2710 | Danielle Rojas-Rousse | Danielle Rojas-Rousse (IRBII), Karine Poitrineau, Cesar Basso | The potential of mass rearing of Monoksa dorsiplana (Pteromalidae) a
native gregarious ectoparasitoid of Pseudopachymeria spinipes (Bruchidae)in
South America | null | Biological Control 41 (30/04/2007) 348-353 | null | null | q-bio.PE | null | In Chile and Uruguay,the gregarious Pteromalidae (Monoksa dorsiplana) has
been discovered emerging from seeds of the persistent pods of Acacia caven
attacked by the univoltin bruchid Pseudopachymeria spinipes. We investigated
the potential for mass rearing of this gregarious ectoparasitoid on an
alternative bruchid host, Callosobruchus maculatus, to use it against the
bruchidae of native and cultured species of Leguminosea seeds in South America.
The mass rearing of M.dorsiplana was carried out in a population cage where the
density of egg-laying females per infested seed was increased from 1:1 on the
first day to 5:1 on the last (fifth) day. Under these experimental conditions
egg-clutch size per host increased, and at the same time the mortality of eggs
laid also increased. The density of egg-laying females influenced the sex ratio
which tended towards a balance of sons and daughters,in contrast to the sex
ratio of a single egg-laying female per host (1 son to 7 daughters). The mean
weight of adults emerging from a parasitized host was negatively correlated
with the egg-clutch size, i.e., as egg-clutch size increased, adult weight
decreased. All these results show that mass rearing of the gregarious
ectoparasitoid M.dorsiplana was possible under laboratory conditions on an
alternative bruchid host C.maculatus. As M.dorsiplana is a natural enemy of
larval and pupal stages of bruchidae, the next step was to investigate whether
the biological control of bruchid C.maculatus was possible in an experimental
structure of stored beans.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:29:40 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rojas-Rousse",
"Danielle",
"",
"IRBII"
],
[
"Poitrineau",
"Karine",
""
],
[
"Basso",
"Cesar",
""
]
] |
0705.2711 | F\`elix Campelo | F. Campelo and A. Hernandez-Machado | Shape instabilities in vesicles: a phase-field model | null | Eur. Phys. J. Special Topics, 143: 101-108 (2007) | 10.1140/epjst/e2007-00077-y | null | cond-mat.soft q-bio.QM | null | A phase field model for dealing with shape instabilities in fluid membrane
vesicles is presented. This model takes into account the Canham-Helfrich
bending energy with spontaneous curvature. A dynamic equation for the
phase-field is also derived. With this model it is possible to see the vesicle
shape deformation dynamically, when some external agent instabilizes the
membrane, for instance, inducing an inhomogeneous spontaneous curvature. The
numerical scheme used is detailed and some stationary shapes are shown together
with a shape diagram for vesicles of spherical topology and no spontaneous
curvature, in agreement with known results.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:29:42 GMT"
}
] | 2007-07-26T00:00:00 | [
[
"Campelo",
"F.",
""
],
[
"Hernandez-Machado",
"A.",
""
]
] |
0705.2712 | Jeremy S. Sanders | J. S. Sanders, A. C. Fabian (Institute of Astronomy, Cambridge) | A deeper X-ray study of the core of the Perseus galaxy cluster: the
power of sound waves and the distribution of metals and cosmic rays | Accepted by MNRAS. Now includes evidence for further ancient bubble
at 170 kpc radius, and minor changes suggested by referee. A version with
good quality figures is available from
http://www-xray.ast.cam.ac.uk/papers/perdetail2.pdf | null | 10.1111/j.1365-2966.2007.12347.x | null | astro-ph | null | We make a further study of the very deep Chandra observation of the X-ray
brightest galaxy cluster, A426 in Perseus. We examine the radial distribution
of energy flux inferred by the quasi-concentric ripples in surface brightness,
assuming they are due to sound waves, and show that it is a significant
fraction of the energy lost by radiative cooling within the inner 75-100 kpc,
where the cooling time is 4-5 Gyr, respectively. The wave flux decreases
outward with radius, consistent with energy being dissipated. Some newly
discovered large ripples beyond 100 kpc, and a possible intact bubble at 170
kpc radius, may indicate a larger level of activity by the nucleus a few 100
Myr ago. The distribution of metals in the intracluster gas peaks at a radius
of about 40 kpc and is significantly clumpy on scales of 5 kpc. The temperature
distribution of the soft X-ray filaments and the hard X-ray emission component
found within the inner 50 kpc are analysed in detail. The pressure due to the
nonthermal electrons, responsible for a spectral component interpreted as
inverse Compton emission, is high within 40 kpc of the centre and boosts the
power in sound waves there; it drops steeply beyond 40 kpc. We find no thermal
emission from the radio bubbles; in order for any thermal gas to have a filling
factor within the bubbles exceeding 50 per cent, the temperature of that gas
has to exceed 50 keV.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:16:56 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Aug 2007 11:55:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sanders",
"J. S.",
"",
"Institute of Astronomy, Cambridge"
],
[
"Fabian",
"A. C.",
"",
"Institute of Astronomy, Cambridge"
]
] |
0705.2713 | Keiichi Maeda | K. Maeda, M. Tanaka, K.Nomoto, N. Tominaga, K. Kawabata, P.A. Mazzali,
H. Umeda, T.Suzuki, T. Hattori | The Unique Type Ib Supernova 2005bf at Nebular Phases: A Possible Birth
Event of A Strongly Magnetized Neutron Star | 16 pages, 12 figures. Accepted by the Astrophysical Journal | Astrophys.J.666:1069-1082,2007 | 10.1086/520054 | null | astro-ph | null | Late phase nebular spectra and photometry of Type Ib Supernova (SN) 2005bf
taken by the Subaru telescope at ~ 270 and ~ 310 days since the explosion are
presented. Emission lines ([OI]6300, 6363, [CaII]7291, 7324, [FeII]7155) show
the blueshift of ~ 1,500 - 2,000 km s-1. The [OI] doublet shows a doubly-peaked
profile. The line luminosities can be interpreted as coming from a blob or jet
containing only ~ 0.1 - 0.4 Msun, in which ~ 0.02 - 0.06 Msun is 56Ni
synthesized at the explosion. To explain the blueshift, the blob should either
be of unipolar moving at the center-of-mass velocity v ~ 2,000 - 5,000 km s-1,
or suffer from self-absorption within the ejecta as seen in SN 1990I. In both
interpretations, the low-mass blob component dominates the optical output both
at the first peak (~ 20 days) and at the late phase (~ 300 days). The low
luminosity at the late phase (the absolute R magnitude M_R ~ -10.2 mag at ~ 270
days) sets the upper limit for the mass of 56Ni < ~ 0.08 Msun, which is in
contradiction to the value necessary to explain the second, main peak
luminosity (M_R ~ -18.3 mag at ~ 40 days). Encountered by this difficulty in
the 56Ni heating model, we suggest an alternative scenario in which the heating
source is a newly born, strongly magnetized neutron star (a magnetar) with the
surface magnetic field Bmag ~ 10^{14-15} gauss and the initial spin period P0 ~
10 ms. Then, SN 2005bf could be a link between normal SNe Ib/c and an X-Ray
Flash associated SN 2006aj, connected in terms of Bmag and/or P0.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 14:41:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Maeda",
"K.",
""
],
[
"Tanaka",
"M.",
""
],
[
"Nomoto",
"K.",
""
],
[
"Tominaga",
"N.",
""
],
[
"Kawabata",
"K.",
""
],
[
"Mazzali",
"P. A.",
""
],
[
"Umeda",
"H.",
""
],
[
"Suzuki",
"T.",
""
],
[
"Hattori",
"T.",
""
]
] |
0705.2714 | Brendan Hassett | Brendan Hassett and Yuri Tschinkel | Log Fano varieties over function fields of curves | 18 pages | null | 10.1007/s00222-008-0113-2 | null | math.AG math.NT | null | Consider a smooth log Fano variety over the function field of a curve.
Suppose that the boundary has positive normal bundle. Choose an integral model
over the curve. Then integral points are Zariski dense, after removing an
explicit finite set of points on the base curve.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:00:44 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hassett",
"Brendan",
""
],
[
"Tschinkel",
"Yuri",
""
]
] |
0705.2715 | Lorenzo Nicolodi | Emilio Musso, Lorenzo Nicolodi | Differential systems associated with tableaux over Lie algebras | 16 pages; to appear in: "Symmetries and Overdetermined Systems of
Partial Differential Equations" (M. Eastwood and W. Miller, Jr., eds.), IMA
Volumes in Mathematics and Its Applications, Springer-Verlag, New York | IMA Vol. Math. Appl., 144, Springer, New York, 2008, 497-514 | null | null | math.DG | null | We give an account of the construction of exterior differential systems based
on the notion of tableaux over Lie algebras as developed in [Comm. Anal. Geom
14 (2006), 475-496; math.DG/0412169]. The definition of a tableau over a Lie
algebra is revisited and extended in the light of the formalism of the Spencer
cohomology; the question of involutiveness for the associated systems and their
prolongations is addressed; examples are discussed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:02:26 GMT"
}
] | 2007-12-06T00:00:00 | [
[
"Musso",
"Emilio",
""
],
[
"Nicolodi",
"Lorenzo",
""
]
] |
0705.2716 | Frank G\"ohmann | Herman E. Boos, Frank G\"ohmann, Andreas Kl\"umper and Junji Suzuki | Factorization of the finite temperature correlation functions of the XXZ
chain in a magnetic field | 35 pages | J.Phys.A40:10699-10728,2007 | 10.1088/1751-8113/40/35/001 | null | hep-th cond-mat.str-el | null | We present a conjecture for the density matrix of a finite segment of the XXZ
chain coupled to a heat bath and to a constant longitudinal magnetic field. It
states that the inhomogeneous density matrix, conceived as a map which
associates with every local operator its thermal expectation value, can be
written as the trace of the exponential of an operator constructed from
weighted traces of the elements of certain monodromy matrices related to $U_q
(\hat{\mathfrak{sl}}_2)$ and only two transcendental functions pertaining to
the one-point function and the neighbour correlators, respectively. Our
conjecture implies that all static correlation functions of the XXZ chain are
polynomials in these two functions and their derivatives with coefficients of
purely algebraic origin.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:06:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Boos",
"Herman E.",
""
],
[
"Göhmann",
"Frank",
""
],
[
"Klümper",
"Andreas",
""
],
[
"Suzuki",
"Junji",
""
]
] |
0705.2717 | Edouard Bernard | M. Monelli (for the LCID Team) | The ACS LCID Project: data reduction strategy | 2 pages, 1 figure. To appear in the Proceedings of IAU Symposium 241:
"Stellar Populations as Building Blocks of Galaxies", 10-16 December, 2006 at
La Palma, Canary Islands, Spain | null | 10.1017/S1743921307008502 | null | astro-ph | null | During Cycle 14 a total of 113 HST orbits were secured to observe five
isolated dwarf galaxies, namely Tucana, LGS3, LeoA, IC1613, and Cetus. The aim
of the project is a full characterization of the stellar content of these
galaxies, in term of their SFH, radial distributions, halo populations and
variable stars. Deep (V~29) F475W, F814W data allowed us to fully sample all
the evolutionary phases from the tip of the Red Giant Branch (RGB) to well
below the old Main Sequence Turnoff (MSTO). Here we describe the observational
design, and the reduction and calibration strategy adopted. A comparison of the
results obtained using two different packages, ALLFRAME and Dolphot, is
presented.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:07:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Monelli",
"M.",
"",
"for the LCID Team"
]
] |
0705.2718 | Thomas Heinzl | Tom Heinzl, Kurt Langfeld, Martin Lavelle and David McMullan | Coulomb gauge Gribov copies and the confining potential | 22 pages, 9 figures, v2: minor changes, references added | Phys.Rev.D76:114510,2007 | 10.1103/PhysRevD.76.114510 | null | hep-lat hep-ph hep-th | null | We study the approach, initiated by Marinari et al., to the static
inter-quark potential based on Polyakov lines of finite temporal extent,
evaluated in Coulomb gauge. We show that, at small spatial separations, the
potential can be understood as being between two separately gauge invariant
colour charges. At larger separations Gribov copies obstruct the
non-perturbative identification of individually gauge invariant colour states.
We demonstrate, for the first time, how gauge invariance can be maintained
quite generally by averaging over Gribov copies. This allows us to extend the
analysis of the Polyakov lines and the corresponding, gauge invariant
quark-antiquark state to all distance scales. Using large scale lattice
simulations, we show that this interpolating state possesses a good overlap
with the ground state in the quark-antiquark sector and yields the full static
inter-quark potential at all distances. A visual representation of the Gribov
copies on the lattice is also presented.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:18:03 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Sep 2007 09:13:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Heinzl",
"Tom",
""
],
[
"Langfeld",
"Kurt",
""
],
[
"Lavelle",
"Martin",
""
],
[
"McMullan",
"David",
""
]
] |
0705.2719 | Edouard Bernard | Carme Gallart (for the LCID Team) | The ACS LCID Project: overview and first results | 4 pages, 2 figures. To appear in the Proceedings of IAU Symposium
241: "Stellar Populations as Building Blocks of Galaxies", 10-16 December,
2006 at La Palma, Canary Islands, Spain | null | 10.1017/S1743921307008186 | null | astro-ph | null | The star formation history (SFH) of Local Group galaxies is a powerful tool
for studying their evolution, including chemical enrichment histories and
stellar population gradients, which in turn may shed light on the role of
reionization or Supernovae feedback in galaxy formation and evolution. In
particular, isolated dwarfs are ideal laboratories since their evolution has
not been complicated by the vicinity of giant galaxies. In this paper, we
present the project Local Cosmology from Isolated Dwarfs (LCID), aimed at
deriving detailed SFHs for a sample of Local Group isolated dwarf galaxies. To
accomplish this goal we have collected, using the ACS on board the HST,
color-magnitude diagrams (CMD) reaching their oldest main sequence turnoff
(V~28 or M_V~+3.5) with good photometric accuracy. Some preliminary results
from the CMDs are shown and briefly discussed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:33:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gallart",
"Carme",
"",
"for the LCID Team"
]
] |
0705.2720 | Ali Mohammad-Djafari | Ali Mohammad-Djafari | Inverse problems in imaging systems and the general Bayesian inversion
frawework | 34 page, 16 figures, to appear in AIEEE | null | null | null | physics.data-an physics.comp-ph | null | In this paper, first a great number of inverse problems which arise in
instrumentation, in computer imaging systems and in computer vision are
presented. Then a common general forward modeling for them is given and the
corresponding inversion problem is presented. Then, after showing the
inadequacy of the classical analytical and least square methods for these ill
posed inverse problems, a Bayesian estimation framework is presented which can
handle, in a coherent way, all these problems. One of the main steps, in
Bayesian inversion framework is the prior modeling of the unknowns. For this
reason, a great number of such models and in particular the compound hidden
Markov models are presented. Then, the main computational tools of the Bayesian
estimation are briefly presented. Finally, some particular cases are studied in
detail and new results are presented.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:17:12 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mohammad-Djafari",
"Ali",
""
]
] |
0705.2721 | Alvaro Corral | Alvaro Corral, Luciano Telesca, and Rosa Lasaponara | Scaling and correlations in the dynamics of forest-fire occurrence | Not a long paper, but many figures (but no large size in kb) | null | 10.1103/PhysRevE.77.016101 | null | physics.geo-ph | null | Forest-fire waiting times, defined as the time between successive events
above a certain size in a given region, are calculated for Italy. The
probability densities of the waiting times are found to verify a scaling law,
despite that fact that the distribution of fire sizes is not a power law. The
meaning of such behavior in terms of the possible self-similarity of the
process in a nonstationary system is discussed. We find that the scaling law
arises as a consequence of the stationarity of fire sizes and the existence of
a non-trivial ``instantaneous'' scaling law, sustained by the correlations of
the process.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:26:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Corral",
"Alvaro",
""
],
[
"Telesca",
"Luciano",
""
],
[
"Lasaponara",
"Rosa",
""
]
] |
0705.2722 | Dominique Eckert M. | D. Eckert, A. Neronov, T. J.-L. Courvoisier and N. Produit | South-West extension of the hard X-ray emission from the Coma cluster | 7pages, 10 figures | null | 10.1051/0004-6361:20077268 | null | astro-ph | null | We explore the morphology of hard (18-30 keV) X-ray emission from the Coma
cluster of galaxies. We analyze a deep (1.1 Ms) observation of the Coma cluster
with the ISGRI imager on board the \emph{INTEGRAL} satellite. We show that the
source extension in the North-East to South-West (SW) direction ($\sim 17'$)
significantly exceeds the size of the point spread function of ISGRI, and that
the centroid of the image of the source in the 18-30 keV band is displaced in
the SW direction compared to the centroid in the 1-10 keV band. To test the
nature of the SW extension we fit the data assuming different models of source
morphology. The best fit is achieved with a diffuse source of elliptical shape,
although an acceptable fit can be achieved assuming an additional point source
SW of the cluster core. In the case of an elliptical source, the direction of
extension of the source coincides with the direction toward the subcluster
falling onto the Coma cluster. If the SW excess is due to the presence of a
point source with a hard spectrum, we show that there is no obvious X-ray
counterpart for this additional source, and that the closest X-ray source is
the quasar EXO 1256+281, which is located $6.1'$ from the centroid of the
excess. The observed morphology of the hard X-ray emission clarifies the nature
of the hard X-ray "excess" emission from the Coma cluster, which is due to the
presence of an extended hard X-ray source SW of the cluster core.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:58:58 GMT"
},
{
"version": "v2",
"created": "Tue, 5 Jun 2007 12:03:51 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Sep 2007 08:09:11 GMT"
}
] | 2007-09-03T00:00:00 | [
[
"Eckert",
"D.",
""
],
[
"Neronov",
"A.",
""
],
[
"Courvoisier",
"T. J. -L.",
""
],
[
"Produit",
"N.",
""
]
] |
0705.2723 | Giampiero Esposito Dr. | Giampiero Esposito, Cosimo Stornaiolo | A new antisymmetric bilinear map for type-I gauge theories | 10 pages | Int.J.Geom.Meth.Mod.Phys.4:1107-1115,2007 | 10.1142/S0219887807002466 | DSF 2007/17 | hep-th | null | In the case of gauge theories, which are ruled by an infinite-dimensional
invariance group, various choices of antisymmetric bilinear maps on field
functionals are indeed available. This paper proves first that, within this
broad framework, the Peierls map (not yet the bracket) is a member of a larger
family. At that stage, restriction to gauge-invariant functionals of the
fields, with the associated Ward identities and geometric structure of the
space of histories, make it possible to prove that the new map is indeed a
Poisson bracket in the simple but relevant case of Maxwell theory. The building
blocks are available for gauge theories only: vector fields that leave the
action functional invariant; the invertible gauge-field operator, and the Green
function of the ghost operator.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:37:50 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Esposito",
"Giampiero",
""
],
[
"Stornaiolo",
"Cosimo",
""
]
] |
0705.2724 | Elmar Bittner | Elmar Bittner, Andreas Nussbaumer, Wolfhard Janke, Martin Weigel | Self-affirmation model for football goal distributions | 5 pages, 1 figure | EPL 78 (2007) 58002 | 10.1209/0295-5075/78/58002 | null | physics.soc-ph cond-mat.stat-mech | null | Analyzing football score data with statistical techniques, we investigate how
the highly co-operative nature of the game is reflected in averaged properties
such as the distributions of scored goals for the home and away teams. It turns
out that in particular the tails of the distributions are not well described by
independent Bernoulli trials, but rather well modeled by negative binomial or
generalized extreme value distributions. To understand this behavior from first
principles, we suggest to modify the Bernoulli random process to include a
simple component of self-affirmation which seems to describe the data
surprisingly well and allows to interpret the observed deviation from Gaussian
statistics. The phenomenological distributions used before can be understood as
special cases within this framework. We analyzed historical football score data
from many leagues in Europe as well as from international tournaments and found
the proposed models to be applicable rather universally. In particular, here we
compare men's and women's leagues and the separate German leagues during the
cold war times and find some remarkable differences.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 15:58:23 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bittner",
"Elmar",
""
],
[
"Nussbaumer",
"Andreas",
""
],
[
"Janke",
"Wolfhard",
""
],
[
"Weigel",
"Martin",
""
]
] |
0705.2725 | Aleksey Zinger | Aleksey Zinger | Genus-Zero Two-Point Hyperplane Integrals in the Gromov-Witten Theory | a number of changes to the introduction; 32 pages, 4 figures, 1 table | null | null | null | math.AG math.SG | null | In this paper we compute certain two-point integrals over a moduli space of
stable maps into projective space. Computation of one-point analogues of these
integrals constitutes a proof of mirror symmetry for genus-zero one-point
Gromov-Witten invariants of projective hypersurfaces. The integrals computed in
this paper constitute a significant portion in the proof of mirror symmetry for
genus-one GW-invariants completed in a separate paper. These integrals also
provide explicit mirror formulas for genus-zero two-point GW-invariants of
projective hypersurfaces. The approach described in this paper leads to a
reconstruction algorithm for all genus-zero GW-invariants of projective
hypersurfaces.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:06:59 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 00:37:25 GMT"
}
] | 2007-08-02T00:00:00 | [
[
"Zinger",
"Aleksey",
""
]
] |
0705.2726 | Barbara Ercolano Dr | B. Ercolano (1,2), N. Bastian (2), G. Stasinska (3) ((1)
Harvard/Smithsonian Center for Astrophysics, Cambridge, MA, USA; (2)
University College London, London, UK; (3) LUTH, Observatoire de Paris,
Paris, France) | The effects of spatially distributed ionisation sources on the
temperature structure of HII region | 13 pages, 6 figures, Accepted by MNRAS | Mon.Not.Roy.Astron.Soc.379:945-955,2007 | 10.1111/j.1365-2966.2007.12002.x | null | astro-ph | null | Spatially resolved studies of star forming regions show that the assumption
of spherical geometry is not realistic in most cases, with a major complication
posed by the gas being ionised by multiple non-centrally located stars or star
clusters. We try to isolate the effects of multiple non-centrally located stars
on the temperature and ionisation structure of HII regions, via the
construction of 3D photoionisation models using the 3D Monte Carlo
photoionisation code MOCASSIN. We find that the true temperature fluctuations
due to the stellar distribution (as opposed to the large-scale temperature
gradients due to other gas properties) are small in all cases and not a
significant cause of error in metallicity studies. Strong emission lines from
HII regions are often used to study the metallicity of star-forming regions. We
compare integrated emission line spectra from our models and quantify any
systematic errors caused by the simplifying assumption of a single, central
location for all ionising sources. We find that the dependence of the
metallicity indicators on the ionisation parameter causes a clear bias, due to
the fact that models with a fully distributed configuration of stars always
display lower ionisation parameters than their fully concentrated counterparts.
The errors found imply that the geometrical distribution of ionisation sources
may partly account for the large scatter in metallicities derived using
model-calibrated empirical methods.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:10:14 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Ercolano",
"B.",
""
],
[
"Bastian",
"N.",
""
],
[
"Stasinska",
"G.",
""
]
] |
0705.2727 | Alexander N. Poddubny | A.N. Poddubny and S.V. Goupalov | Coherent defect-assisted multiphonon intraband carrier relaxation in
semiconductor quantum dots | 7 pages, 3 figures, submitted to Phys.Rev. B | null | 10.1103/PhysRevB.77.075315 | null | cond-mat.mes-hall | null | new defect-assisted mechanism of multiphonon intraband carrier relaxation in
semiconductor quantum dots, where the carrier is found in a coherent
superposition of the initial, final, and defect states, is proposed. It is
shown that this mechanism is capable of explaining the observed trends in
temperature dependences of the intraband relaxation rates for PbSe and CdSe
colloidal nanocrystal quantum dots.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:18:09 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Poddubny",
"A. N.",
""
],
[
"Goupalov",
"S. V.",
""
]
] |
0705.2728 | Hannes H\"ubener | Hannes H\"ubener and Tobias Brandes | Vibrational Coherences in Nano-Elastic Tunneling | 4 pages, 4 figures | Phys. Rev. Lett. 99, 247206 (2007) | 10.1103/PhysRevLett.99.247206 | null | cond-mat.mes-hall | null | Charging a nano-scale oscillator by single electron tunneling leads to an
effective double-well potential due to image charges. We combine exact
numerical diagonalizations with generalized Master equations and show that the
resulting quantum tunneling of the mechanical degree of freedom can be
visualized in the electronic current noise spectrum.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:20:36 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Aug 2007 09:25:45 GMT"
},
{
"version": "v3",
"created": "Wed, 15 Aug 2007 20:28:21 GMT"
},
{
"version": "v4",
"created": "Thu, 25 Oct 2007 14:35:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hübener",
"Hannes",
""
],
[
"Brandes",
"Tobias",
""
]
] |
0705.2729 | Carlos Bertulani | C.A. Bertulani, V.V. Flambaum, and V.G. Zelevinsky | Tunneling of a composite particle: Effects of intrinsic structure | 6 pages, 3 figures, version to be published in Journal of Physics G | J.Phys.G34:2289-2296,2007 | 10.1088/0954-3899/34/11/006 | null | nucl-th | null | We consider simple models of tunneling of an object with intrinsic degrees of
freedom. This important problem was not extensively studied until now, in spite
of numerous applications in various areas of physics and astrophysics. We show
possibilities of enhancement for the probability of tunneling due to the
presence of intrinsic degrees of freedom split by weak external fields or by
polarizability of the slow composite object.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:22:33 GMT"
},
{
"version": "v2",
"created": "Fri, 18 May 2007 21:09:56 GMT"
},
{
"version": "v3",
"created": "Wed, 5 Sep 2007 16:47:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bertulani",
"C. A.",
""
],
[
"Flambaum",
"V. V.",
""
],
[
"Zelevinsky",
"V. G.",
""
]
] |
0705.2730 | Paul Frampton | Paul H. Frampton | Cyclic Universe and Infinite Past | 7 pages. Clarification in discussion of infinite past | Mod.Phys.Lett.A22:2587-2592,2007 | 10.1142/S0217732307025698 | null | astro-ph gr-qc hep-ph hep-th | null | We address two questions about the past for infinitely cyclic cosmology. The
first is whether it can contain an infinite length null geodesic into the past
in view of the Borde-Guth-Vilenkin (BGV) "no-go" theorem, The second is
whether, given that a small fraction of spawned universes fail to cycle, there
is an adequate probability for a successful universe after an infinite time. We
give positive answers to both questions then show that in infinite cyclicity
the total number of universes has been infinite for an arbitrarily long time.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:22:52 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jun 2007 18:43:44 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Frampton",
"Paul H.",
""
]
] |
0705.2731 | Boldizsar Kalmar | Boldizsar Kalmar | Fold maps and immersions from the viewpoint of cobordism | revised, 16 pages, 1 figure | Pacific J. Math. 239 (2009), 317-342. | null | null | math.GT math.AT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We obtain complete geometric invariants of cobordism classes of oriented
simple fold maps of (n+1)-dimensional manifolds into an n-dimensional manifold
N in terms of immersions with prescribed normal bundles. We compute that this
cobordism group of simple fold maps is isomorphic to the direct sum of the
(n-1)th stable homotopy group of spheres and the (n-1)th stable homotopy group
of the infinite dimensional projective space. By using geometric invariants
defined in the author's earlier works, we also describe the natural map of the
simple fold cobordism group to the fold cobordism group by natural
homomorphisms between cobordism groups of immersions. We also compute the ranks
of the oriented (right-left) bordism groups of simple fold maps.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:29:50 GMT"
},
{
"version": "v2",
"created": "Wed, 23 Jul 2008 14:50:11 GMT"
}
] | 2009-02-24T00:00:00 | [
[
"Kalmar",
"Boldizsar",
""
]
] |
0705.2732 | Ippei Danshita | Ippei Danshita, James E. Williams, Carlos A. R. Sa de Melo, and
Charles W. Clark | Quantum phases of bosons in double-well optical lattices | 5 pages, 5 figures | Phys. Rev. A 76, 043606 (2007) | 10.1103/PhysRevA.76.043606 | null | cond-mat.other | null | We study the superfluid to Mott insulator transition of bosons in a
two-legged ladder optical lattice, of a type accessible in current experiments
on double-well optical lattices. The zero-temperature phase diagram is mapped
out, with a focus on its dependence upon interchain hopping and the tilt
between double wells. We find that the unit-filling Mott phase exhibits a
non-monotonic behavior as a function of the tilt parameter, producing a
reentrant phase transition between Mott insulator and superfluid phases.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:38:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Danshita",
"Ippei",
""
],
[
"Williams",
"James E.",
""
],
[
"de Melo",
"Carlos A. R. Sa",
""
],
[
"Clark",
"Charles W.",
""
]
] |
0705.2733 | Khireddine Nouicer | Khireddine Nouicer | Entropy of the Randall-Sundrum black brane world to all orders in the
Planck length | 19 pages, 1 figure. (v2): section 4 improved | Class.Quant.Grav.25:075010,2008 | 10.1088/0264-9381/25/7/075010 | null | gr-qc | null | We study the effects, to all orders in the Planck length from a generalized
uncertainty principle (GUP), on the statistical entropy of massive scalar bulk
fields in the Randall-Sundrum black brane world. We show that the
Bekenstein-Hawking area law is not preserved, and contains small corrections
terms proportional to the black hole inverse area.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:32:04 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Nov 2007 17:24:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nouicer",
"Khireddine",
""
]
] |
0705.2734 | Miklos Bona | Mikl\'os B\'ona, Istv\'an Mez\H{o} | Real Zeros and Partitions without singleton blocks | 16 pages | null | 10.1016/j.ejc.2015.07.021 | null | math.CO math.PR | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We prove that the generating polynomials of partitions of an $n$-element set
into non-singleton blocks, counted by the number of blocks, have real roots
only and we study the asymptotic behavior of the leftmost roots. We apply this
information to find the most likely number of blocks.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:04:08 GMT"
},
{
"version": "v2",
"created": "Fri, 18 May 2007 21:16:03 GMT"
},
{
"version": "v3",
"created": "Thu, 6 Aug 2015 16:08:03 GMT"
}
] | 2015-08-07T00:00:00 | [
[
"Bóna",
"Miklós",
""
],
[
"Mező",
"István",
""
]
] |
0705.2735 | Sergio Fenley | Sergio R Fenley | Rigidity of pseudo-Anosov flows transverse to R-covered foliations | 20 pages | null | null | null | math.GT math.DS | null | A foliation is R-covered if the leaf space in the universal cover is
homeomorphic to the real numbers. We show that, up to topological conjugacy,
there are at most two pseudo-Anosov flows transverse to such a foliation. If
there are two, then the foliation is weakly conjugate to the the stable
foliation of an R-covered Anosov flow. The proof uses the universal circle to
R-covered foliations.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:36:55 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fenley",
"Sergio R",
""
]
] |
0705.2736 | Jeroen M. Stil | A. R. Taylor, J. M. Stil, J. K. Grant, T. L. Landecker, R. Kothes, R.
I. Reid, A. D. Gray, Douglas Scott, P. G. Martin, A. I. Boothroyd, G. Joncas,
Felix J. Lockman, J. English, A. Sajina, J. R. Bond | Radio Polarimetry of the ELAIS N1 Field: Polarized Compact Sources | 28 pages, 8 Figures. Figures 2 and 3 as separate gif images. Accepted
for publication in the Astrophysical Journal | Astrophys.J.666:201-211,2007 | 10.1086/519786 | null | astro-ph | null | We present deep polarimetric observations at 1420 MHz of the European Large
Area ISO Survey North 1 region (ELAIS N1) as part of the Dominion Radio
Astrophysical Observatory Planck Deep Fields project. By combining closely
spaced aperture synthesis fields, we image a region of 7.43 square degrees to a
maximum sensitivity in Stokes Q and U of 78 microJy/beam, and detect 786
compact sources in Stokes I. Of these, 83 exhibit polarized emission. We find
that the differential source counts (log N - log p) for polarized sources are
nearly constant down to p > 500 microJy, and that these faint polarized radio
sources are more highly polarized than the strong source population. The median
fractional polarization is (4.8 +/- 0.7)% for polarized sources with Stokes I
flux density between 1 and 30 mJy; approximately three times larger than
sources with I > 100 mJy. The majority of the polarized sources have been
identified with galaxies in the Spitzer Wide Area Infrared Extragalactic Survey
(SWIRE) image of ELAIS N1. Most of the galaxies occupy regions in the IRAC
5.8/3.6 micron vs. 8.0/4.5 micron color-color diagram associated with dusty
AGNs, or with ellipticals with an aging stellar population. A few host galaxies
have colors that suggests significant PAH emission in the near-infrared. A
small fraction, 12%, of the polarized sources are not detected in the SWIRE
data. None of the polarized sources in our sample appears to be associated with
an actively star-forming galaxy.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:37:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Taylor",
"A. R.",
""
],
[
"Stil",
"J. M.",
""
],
[
"Grant",
"J. K.",
""
],
[
"Landecker",
"T. L.",
""
],
[
"Kothes",
"R.",
""
],
[
"Reid",
"R. I.",
""
],
[
"Gray",
"A. D.",
""
],
[
"Scott",
"Douglas",
""
],
[
"Martin",
"P. G.",
""
],
[
"Boothroyd",
"A. I.",
""
],
[
"Joncas",
"G.",
""
],
[
"Lockman",
"Felix J.",
""
],
[
"English",
"J.",
""
],
[
"Sajina",
"A.",
""
],
[
"Bond",
"J. R.",
""
]
] |
0705.2737 | Armin Ridinger | A. Ridinger and N. Davidson | Particle Motion in Rapidly Oscillating Potentials: The Role of the
Potential's Initial Phase | 9 pages, 8 figures, published in PRA | Phys. Rev. A 76, 013421 (2007) | 10.1103/PhysRevA.76.013421 | null | cond-mat.other | null | Rapidly oscillating potentials with a vanishing time average have been used
for a long time to trap charged particles in source-free regions. It has been
argued that the motion of a particle in such a potential can be approximately
described by a time independent effective potential, which does not depend upon
the initial phase of the oscillating potential. However, here we show that the
motion of a particle and its trapping condition significantly depend upon this
initial phase for arbitrarily high frequencies of the potential's oscillation.
We explain this novel phenomenon by showing that the motion of a particle is
determined by the effective potential stated in the literature only if its
initial conditions are transformed according to a transformation which we show
to significantly depend on the potential's initial phase for arbitrarily high
frequencies. We confirm our theoretical findings by numerical simulations.
Further, we demonstrate that the found phenomenon offers new ways to manipulate
the dynamics of particles which are trapped by rapidly oscillating potentials.
Finally, we propose a simple experiment to verify the theoretical findings of
this work.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:38:25 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 13:07:11 GMT"
},
{
"version": "v3",
"created": "Fri, 27 Jul 2007 20:23:14 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Ridinger",
"A.",
""
],
[
"Davidson",
"N.",
""
]
] |
0705.2738 | M. I. Dyakonov | M. I. Dyakonov | Magnetoresistance due to edge spin accumulation | 4 pages, 3 figures. Minor corrections corresponding to the published
version | Phys. Rev. Lett. 99, 126601 (2007) | 10.1103/PhysRevLett.99.126601 | null | cond-mat.mes-hall | null | Because of spin-orbit interaction, an electrical current is accompanied by a
spin current resulting in spin accumulation near the sample edges. Due again to
spin-orbit interaction this causes a small decrease of the sample resistance.
An applied magnetic field will destroy the edge spin polarization leading to a
positive magnetoresistance. This effect provides means to study spin
accumulation by electrical measurements. The origin and the general properties
of the phenomenological equations describing coupling between charge and spin
currents are also discussed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:42:40 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 10:47:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dyakonov",
"M. I.",
""
]
] |
0705.2739 | Maximilian F. Hasler | Maximilian F. Hasler | Generalized functions as sequence spaces with ultranorms | null | Integral Transforms and Special Functions 17/2 (2006) 149-156 | 10.1080/10652460500437807 | UAG/AOC-05/15 | math.FA | null | We review our recent formulation of Colombeau type algebras as Hausdorff
sequence spaces with ultranorms, defined by sequences of exponential weights.
We extend previous results and give new perspectives related to echelon type
spaces, possible generalisations, asymptotic algebras, concepts of association,
and applications thereof.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:46:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hasler",
"Maximilian F.",
""
]
] |
0705.2740 | Pooja Gupta | Pooja Gupta, B. C. Choudhary, S. Chatterji and S. Bhattacharya | Study of Direct Photon plus Jet production in CMS Experiment at
\sqrt{s}=14 TeV | 20 Pages, 13 Figures. Accepted in European Journal of Physics C | Eur. Phys. J. C 53, 49-58 (2008) | 10.1140/epjc/s10052-007-0460-y | CMS-NOTE-2007/004 | hep-ex | null | We present simulation results of $\gamma$ + Jet analysis using CMS (Compact
Muon Solenoid) Object-Oriented software at the Large Hadron Collider (LHC)
center of mass energy $\sqrt{s}$=14 TeV. The study of direct photon production
helps in validating the perturbative Quantum Chromodynamics (pQCD) and
providing information on the gluon distribution in the nucleons. Direct photon
processes also constitute a major background to several other Standard Model
(SM) processes and signals of new physics. Thus these processes need to be
understood precisely in the new energy regime. In this work, we have done a
detailed study of the GEANT4 simulated $\gamma$ + jet events generated with
Pythia, and the related background processes. Isolation cuts have been
optimized for direct photon which improves the signal over background ratio by
$\sim25%$ as compared to previous studies done in CMS. The inclusion of a large
$\Delta\phi$ cut between the photon and the leading jet at $40^0$ in the
analysis leads to a further increase of $\sim15%$ in S/B, thus giving an
overall gain of $\sim42%$ in S/B ratio.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:50:10 GMT"
},
{
"version": "v2",
"created": "Fri, 18 May 2007 21:25:16 GMT"
},
{
"version": "v3",
"created": "Tue, 12 Jun 2007 18:51:47 GMT"
},
{
"version": "v4",
"created": "Wed, 24 Oct 2007 10:54:34 GMT"
}
] | 2008-01-24T00:00:00 | [
[
"Gupta",
"Pooja",
""
],
[
"Choudhary",
"B. C.",
""
],
[
"Chatterji",
"S.",
""
],
[
"Bhattacharya",
"S.",
""
]
] |
0705.2741 | Jeroen M. Stil | J. M. Stil, A. R. Taylor | Polarization shadows of extragalactic sources by the local magneto-ionic
ISM | 11 pages, 2 figures. Both figures provided as separate gif images.
Accepted for publication in The Astrophysical Journal Letters | null | 10.1086/519791 | null | astro-ph | null | We report depolarization of extragalactic sources in the NRAO VLA Sky Survey
(NVSS) by local structures in the interstellar medium. The sky density of
polarized sources drops by a factor 2 - 4 in regions with angular scales
approx. 10 degrees, implying up to 40% depolarization on average per source.
Some of these polarization shadows are associated with HII regions, but three
are associated with regions of depolarized diffuse Galactic emission. The
absence of a correlation between the depth of polarization shadows and H-alpha
intensity suggests that some shadows are related to structure in the magnetic
field. At least some polarization shadows are caused by partial bandwidth
depolarization in the NVSS. Alternatively, some may be caused by regions with
small scale (< 1 arcsec) variations in rotation measure.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:52:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stil",
"J. M.",
""
],
[
"Taylor",
"A. R.",
""
]
] |
0705.2742 | Steven J. van Enk | S.J. van Enk | A toy model for quantum mechanics | in which the author breaks his vow to never use the words "ontic" and
"epistemic" in public | Found. Phys. 37, 1447 (2007) | 10.1007/s10701-007-9171-3 | null | quant-ph | null | The toy model used by Spekkens [R. Spekkens, Phys. Rev. A 75, 032110 (2007)]
to argue in favor of an epistemic view of quantum mechanics is extended by
generalizing his definition of pure states (i.e. states of maximal knowledge)
and by associating measurements with all pure states. The new toy model does
not allow signaling but, in contrast to the Spekkens model, does violate
Bell-CHSH inequalities. Negative probabilities are found to arise naturally
within the model, and can be used to explain the Bell-CHSH inequality
violations.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:56:49 GMT"
}
] | 2007-11-08T00:00:00 | [
[
"van Enk",
"S. J.",
""
]
] |
0705.2743 | Damian Scherlis | Damian A. Scherlis, Matteo Cococcioni, Patrick Sit, Nicola Marzari | Simulation of Heme using DFT+U: a step toward accurate spin-state
energetics | To be published in The Journal of Physical Chemistry B 30 pages, 15
figures | null | null | null | cond-mat.soft | null | We investigate the DFT+U approach as a viable solution to describe the
low-lying states of ligated and unligated iron heme complexes. Besides their
central role in organometallic chemistry, these compounds represent a
paradigmatic case where LDA, GGA, and common hybrid functionals fail to
reproduce the experimental magnetic splittings. In particular, the imidazole
pentacoordinated heme is incorrectly described as a triplet by all usual DFT
flavors. In this study we show that a U parameter close to 4 eV leads to spin
transitions and molecular geometries in quantitative agreement with
experiments, and that DFT+U represents an appealing tool in the description of
iron porphyrin complexes, at a much reduced cost compared to correlated
quantum-chemistry methods. The possibility of obtaining the U parameter from
first-principles is explored through a self-consistent linear-response
formulation. We find that this approach, which proved to be successful in other
iron systems, produces in this case some overestimation with respect to the
optimal values of U.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 16:58:31 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Scherlis",
"Damian A.",
""
],
[
"Cococcioni",
"Matteo",
""
],
[
"Sit",
"Patrick",
""
],
[
"Marzari",
"Nicola",
""
]
] |
0705.2744 | Oliver Brein | Oliver Brein and Wolfgang Hollik | Distributions for MSSM Higgs boson + jet production at hadron colliders | 18 pages, 10 figures | Phys.Rev.D76:035002,2007 | 10.1103/PhysRevD.76.035002 | IPPP/07/18, DCPT/07/36, MPP-2007-58 | hep-ph hep-ex | null | We present pseudorapidity and transverse momentum distributions for the cross
section for the production of the lightest neutral Higgs boson in association
with a high-p_T hadronic jet, calculated in the framework of the minimal
supersymmetric standard model (MSSM). We discuss the theoretical predictions
for the differential cross sections at the Large Hadron Collider and the
Tevatron for the most common benchmark scenarios.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:29:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Brein",
"Oliver",
""
],
[
"Hollik",
"Wolfgang",
""
]
] |
0705.2745 | David Merritt | David Merritt, Seppo Mikkola, Andras Szell | Long-Term Evolution of Massive Black Hole Binaries. III. Binary
Evolution in Collisional Nuclei | 21 pages | null | 10.1086/522691 | null | astro-ph | null | [Abridged] In galactic nuclei with sufficiently short relaxation times,
binary supermassive black holes can evolve beyond their stalling radii via
continued interaction with stars. We study this "collisional" evolutionary
regime using both fully self-consistent N-body integrations and approximate
Fokker-Planck models. The N-body integrations employ particle numbers up to
0.26M and a direct-summation potential solver; close interactions involving the
binary are treated using a new implementation of the Mikkola-Aarseth chain
regularization algorithm. Even at these large values of N, two-body scattering
occurs at high enough rates in the simulations that they can not be simply
scaled to the large-N regime of real galaxies. The Fokker-Planck model is used
to bridge this gap; it includes, for the first time, binary-induced changes in
the stellar density and potential. The Fokker-Planck model is shown to
accurately reproduce the results of the N-body integrations, and is then
extended to the much larger N regime of real galaxies. Analytic expressions are
derived that accurately reproduce the time dependence of the binary semi-major
axis as predicted by the Fokker-Planck model. Gravitational wave coalescence is
shown to occur in <10 Gyr in nuclei with velocity dispersions below about 80
km/s. Formation of a core results from a competition between ejection of stars
by the binary and re-supply of depleted orbits via two-body scattering. Mass
deficits as large as ~4 times the binary mass are produced before coalescence.
After the two black holes coalesce, a Bahcall-Wolf cusp appears around the
single hole in one relaxation time, resulting in a nuclear density profile
consisting of a flat core with an inner, compact cluster, similar to what is
observed at the centers of low-luminosity spheroids.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:23:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Merritt",
"David",
""
],
[
"Mikkola",
"Seppo",
""
],
[
"Szell",
"Andras",
""
]
] |
0705.2746 | Steven R. White | Steven R. White and A.L. Chernyshev | Neel order in square and triangular lattice Heisenberg models | 4 pages, 5 figures, typo fixed, reference added | Phys. Rev. Lett. 99, 127004 (2007) | 10.1103/PhysRevLett.99.127004 | null | cond-mat.str-el | null | Using examples of the square- and triangular-lattice Heisenberg models we
demonstrate that the density matrix renormalization group method (DMRG) can be
effectively used to study magnetic ordering in two-dimensional lattice spin
models. We show that local quantities in DMRG calculations, such as the on-site
magnetization M, should be extrapolated with the truncation error, not with its
square root, as previously assumed. We also introduce convenient sequences of
clusters, using cylindrical boundary conditions and pinning magnetic fields,
which provide for rapidly converging finite-size scaling. This scaling behavior
on our clusters is clarified using finite-size analysis of the effective
sigma-model and finite-size spin-wave theory. The resulting greatly improved
extrapolations allow us to determine the thermodynamic limit of M for the
square lattice with an error comparable to quantum Monte Carlo. For the
triangular lattice, we verify the existence of three-sublattice magnetic order,
and estimate the order parameter to be M = 0.205(15).
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:31:19 GMT"
},
{
"version": "v2",
"created": "Tue, 22 May 2007 20:54:21 GMT"
},
{
"version": "v3",
"created": "Sat, 26 May 2007 22:32:36 GMT"
}
] | 2013-08-26T00:00:00 | [
[
"White",
"Steven R.",
""
],
[
"Chernyshev",
"A. L.",
""
]
] |
0705.2747 | Vladimir Gubernov | A.V. Kolobov, V.V. Gubernov, A.A. Polezhaev | Autowaves in the model of avascular tumour growth | 9 pages, 7 figures | null | null | null | q-bio.TO nlin.PS | null | A mathematical model of infiltrative tumour growth taking into account cell
proliferation, death and motility is considered. The model is formulated in
terms of local cell density and nutrient (oxygen) concentration. In the model
the rate of cell death depends on the local nutrient level. Thus heterogeneous
nutrient distribution in tissue affects tumour structure and development. The
existence of automodel solutions is demonstrated and their properties are
investigated. The results are compared to the properties of the
Kolmogorov-Petrovskii-Piskunov and Fisher equations. Influence of the nutrient
distribution on the autowave speed selection as well as on the relaxation to
automodel solution is demonstrated. The model adequately describes the data,
observed in experiments.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:06:02 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kolobov",
"A. V.",
""
],
[
"Gubernov",
"V. V.",
""
],
[
"Polezhaev",
"A. A.",
""
]
] |
0705.2748 | Avazbek Nasirov K | A.K. Nasirov (1,2), A.I. Muminov (2), R.K. Utamuratov (2), G. Fazio
(3), G. Giardina (3), F. Hanappe (4), G. Mandaglio (3), M. Manganaro (3), and
W. Scheid (5) ((1) Flerov Laboratory of Nuclear Reactions, JINR, Dubna,
Russia, (2) Heavy Ion Physics Department, INP, Tashkent, Uzbekistan, (3)
INFN, Sezione di Catania, and Dipartimento di Fisica dell'Universit\`a di
Messina, Messina, Italy, (4) Universit\'e Libre de Bruxelles, Bruxelles,
Belgium, (5) Institut f\"ur Theoretische Physik der Justus-Liebig-
Universit\"at, Giessen, Germany) | Angular anisotropy of the fusion-fission and quasifission fragments | 17 pages 8 figures. Submitted to Euro. Phys. Jour. A | Eur.Phys.J.A34:325-339,2007 | 10.1140/epja/i2007-10504-5 | null | nucl-th | null | The anisotropy in the angular distribution of the fusion-fission and
quasifission fragments for the $^{16}$O+$^{238}$U, $^{19}$F+$^{208}$Pb and
$^{32}$S+$^{208}$Pb reactions is studied by analyzing the angular momentum
distributions of the dinuclear system and compound nucleus which are formed
after capture and complete fusion, respectively. The orientation angles of
axial symmetry axes of colliding nuclei to the beam direction are taken into
account for the calculation of the variance of the projection of the total spin
onto the fission axis. It is shown that the deviation of the experimental
angular anisotropy from the statistical model picture is connected with the
contribution of the quasifission fragments which is dominant in the
$^{32}$S+$^{208}$Pb reaction. Enhancement of anisotropy at low energies in the
$^{16}$O+$^{238}$U reaction is connected with quasifission of the dinuclear
system having low temperature and effective moment of inertia.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:40:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nasirov",
"A. K.",
""
],
[
"Muminov",
"A. I.",
""
],
[
"Utamuratov",
"R. K.",
""
],
[
"Fazio",
"G.",
""
],
[
"Giardina",
"G.",
""
],
[
"Hanappe",
"F.",
""
],
[
"Mandaglio",
"G.",
""
],
[
"Manganaro",
"M.",
""
],
[
"Scheid",
"W.",
""
]
] |
0705.2749 | Raoul Santachiara | Raoul Santachiara | SLE in self-dual critical Z(N) spin systems: CFT predictions | 22 pages, 6 figures. v2: Nuclear Physics B Published version | Nucl. Phys. B 793, 396 (2008) | 10.1016/j.nuclphysb.2007.09.029 | null | cond-mat.stat-mech | null | The Schramm-Loewner evolution (SLE) describes the continuum limit of domain
walls at phase transitions in two dimensional statistical systems. We consider
here the SLEs in the self-dual Z(N) spin models at the critical point. For N=2
and N=3 these models correspond to the Ising and three-state Potts model. For
N>5 the critical self-dual Z(N) spin models are described in the continuum
limit by non-minimal conformal field theories with central charge c>=1. By
studying the representations of the corresponding chiral algebra, we show that
two particular operators satisfy a two level null vector condition which, for
N>=4, presents an additional term coming from the extra symmetry currents
action. For N=2,3 these operators correspond to the boundary conditions
changing operators associated to the SLE_{16/3} (Ising model) and to the
SLE_{24/5} and SLE_{10/3} (three-state Potts model). We suggest a definition of
the interfaces within the Z(N) lattice models. The scaling limit of these
interfaces is expected to be described at the self-dual critical point and for
N>=4 by the SLE_{4(N+1)/(N+2)} and SLE_{4(N+2)/(N+1)} processes.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 17:53:12 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 16:20:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Santachiara",
"Raoul",
""
]
] |
0705.2750 | Carsten Marzok | C. Marzok, B. Deh, Ph.W. Courteille, and C. Zimmermann | Ultracold Thermalization of $^7$Li and $^{87}$Rb | 7 pages, 4 figures, 1 table | null | 10.1103/PhysRevA.76.052704 | null | cond-mat.other | null | We report on measurements of cross-species thermalization inside a
magnetically trapped spin-polarized mixture of $^{87}$Rb and $^7$Li atoms with
both atoms in their respective low field seeking magnetic substates
$|F=2,m_F=2\right>$. Measurement of the thermalization velocity in the
ultracold regime below $10 \mu$K allows for the derivation of the absolute
value of the pure triplet s-wave scattering length governing the interaction.
We find $|a_{7,87}|=(59\pm19) a_{\rm B}$. We propose to study both species in
the condensed regime to derive the sign of $a_{7,87}$. In this context, we
present numerical solutions to the coupled Gross-Pitaevskii equation based on
the hypothesis of a positive sign. According to the simulations, phase
separation of the Li and Rb $|2,2\right>$ clouds occurs along with a mean-field
stabilization allowing for larger atom numbers of condensed $^7$Li atoms before
collapse sets in. Observation of this mean-field stabilization would directly
fix the sign of $a_{7,87}$. We discuss our results in the light of this
proposal.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:09:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marzok",
"C.",
""
],
[
"Deh",
"B.",
""
],
[
"Courteille",
"Ph. W.",
""
],
[
"Zimmermann",
"C.",
""
]
] |
0705.2751 | Alan Sokal | Youjin Deng, Timothy M. Garoni, Jonathan Machta, Giovanni Ossola,
Marco Polin, Alan D. Sokal | Dynamic critical behavior of the Chayes-Machta-Swendsen-Wang algorithm | Revtex4, 4 pages including 4 figures | Phys.Rev.Lett.99:055701,2007 | 10.1103/PhysRevLett.99.055701 | null | cond-mat.stat-mech hep-lat | null | We study the dynamic critical behavior of the Chayes-Machta dynamics for the
Fortuin-Kasteleyn random-cluster model, which generalizes the Swendsen-Wang
dynamics for the q-state Potts model to noninteger q, in two and three spatial
dimensions, by Monte Carlo simulation. We show that the Li-Sokal bound z \ge
\alpha/\nu is close to but probably not sharp in d=2, and is far from sharp in
d=3, for all q. The conjecture z \ge \beta/\nu is false (for some values of q)
in both d=2 and d=3.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:35:46 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Deng",
"Youjin",
""
],
[
"Garoni",
"Timothy M.",
""
],
[
"Machta",
"Jonathan",
""
],
[
"Ossola",
"Giovanni",
""
],
[
"Polin",
"Marco",
""
],
[
"Sokal",
"Alan D.",
""
]
] |
0705.2752 | Xin-Zhong Yan | Xin-Zhong Yan and C. S. Ting | Study of interacting electrons in graphene under the
renormalized-ring-diagram approximation | 11 pages, 13 figures | Phys. Rev. B 76, 155401 (2007). | 10.1103/PhysRevB.76.155401 | null | cond-mat.str-el | null | Using the tight-binding model with long-range Coulomb interactions between
electrons, we study some of the electronic properties of graphene. The Coulomb
interactions are treated with the renormalized-ring-diagram approximation. By
self-consistently solving the integral equations for the Green function, we
calculate the spectral density. The obtained result is in agreement with
experimental observation. In addition, we also compute the density of states,
the distribution functions, and the ground-state energy. Within the present
approximation, we find that the imaginary part of the self-energy fixed at the
Fermi momentum varies as quadratic in energy close to the chemical potential,
regardless the system is doped or not. This result appears to indicate that the
electrons in graphene always behave like a moderately correlated Fermi liquid.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:35:57 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Yan",
"Xin-Zhong",
""
],
[
"Ting",
"C. S.",
""
]
] |
0705.2753 | Lev Glebsky | Valentin Afraimovich and Lev Glebsky | Measures related to (e,n)-complexity functions | null | null | null | null | math.DS math.FA | null | The (e,n)-complexity functions describe total instability of trajectories in
dynamical systems. They reflect an ability of trajectories going through a
Borel set to diverge on the distance $\epsilon$ during the time interval n.
Behavior of the (e, n)-complexity functions as n goes to infinity is reflected
in the properties of special measures. These measures are constructed as limits
of atomic measures supported at points of (e,n)-separated sets. We study such
measures. In particular, we prove that they are invariant if the
(e,n)-complexity function grows subexponentially.
Keywords: Topological entropy, complexity functions, separability.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:48:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Afraimovich",
"Valentin",
""
],
[
"Glebsky",
"Lev",
""
]
] |
0705.2754 | Jean-Philippe Groby | Jean-Philippe Groby (CMAP), Armand Wirgin (LMA), Laurent De Ryck
(ATF), Walter Lauriks (ATF) | Acoustic response of a rigid frame porous medium slab with a periodic
set of inclusions | submitted to Journal of Sound and Vibration | null | null | null | physics.class-ph | null | The acoustic response of a rigid frame porous slab with a periodic set of
inclusions is calculated by use of a multipole method. The acoustic properties,
in particular the absorption, of such a structure are then derived and studied.
Numerical results together with a modal analysis show that the addition of a
periodic set of high-contrast inclusions leads to quasi-modes excitation of
both the slab and the gratings, and to a large increase of the acoustic
absorption of the initial slab, this being partly due to the quasi-modes
excitation.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:44:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Groby",
"Jean-Philippe",
"",
"CMAP"
],
[
"Wirgin",
"Armand",
"",
"LMA"
],
[
"De Ryck",
"Laurent",
"",
"ATF"
],
[
"Lauriks",
"Walter",
"",
"ATF"
]
] |
0705.2755 | Alvaro de Souza Dutra | A. de Souza Dutra, M. Hott and F. A. Barone (UNESP-Campus de
Guaratingueta-DFQ) | Two field BPS solutions for generalized Lorentz breaking models | 12 pages, 2 figures | Phys.Rev.D74:085030,2006 | 10.1103/PhysRevD.74.085030 | null | hep-th | null | In this work we present nonlinear models in two-dimensional space-time of two
interacting scalar fields in the Lorentz and CPT violating scenarios. We
discuss the soliton solutions for these models as well as the question of
stability for them. This is done by generalizing a model recently published by
Barreto and collaborators and also by getting new solutions for the model
introduced by them.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:47:03 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dutra",
"A. de Souza",
"",
"UNESP-Campus de\n Guaratingueta-DFQ"
],
[
"Hott",
"M.",
"",
"UNESP-Campus de\n Guaratingueta-DFQ"
],
[
"Barone",
"F. A.",
"",
"UNESP-Campus de\n Guaratingueta-DFQ"
]
] |
0705.2756 | Christian Boily | C.M. Boily, T. Padmanabhan, A. Paiement | Black Hole Motion as Catalyst of Orbital Resonances | revised version, typos fixed, added references, 20 pages MN style | null | 10.1017/S1743921308015834 | null | astro-ph gr-qc | null | The motion of a black hole about the centre of gravity of its host galaxy
induces a strong response from the surrounding stellar population. We treat the
case of a harmonic potential analytically and show that half of the stars on
circular orbits in that potential shift to an orbit of lower energy, while the
other half receive a positive boost and recede to a larger radius. The black
hole itself remains on an orbit of fixed amplitude and merely acts as a
catalyst for the evolution of the stellar energy distribution function f(E). We
show that this effect is operative out to a radius of approx 3 to 4 times the
hole's influence radius, R_bh. We use numerical integration to explore more
fully the response of a stellar distribution to black hole motion. We consider
orbits in a logarithmic potential and compare the response of stars on circular
orbits, to the situation of a `warm' and `hot' (isotropic) stellar velocity
field. While features seen in density maps are now wiped out, the kinematic
signature of black hole motion still imprints the stellar line-of-sight mean
velocity to a magnitude ~18% the local root mean-square velocity dispersion
sigma.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:47:38 GMT"
},
{
"version": "v2",
"created": "Sat, 23 Jun 2007 14:30:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Boily",
"C. M.",
""
],
[
"Padmanabhan",
"T.",
""
],
[
"Paiement",
"A.",
""
]
] |
0705.2757 | Emmanuel Humbert | Bernd Ammann (IECN), Emmanuel Humbert (IECN), Bertrand Morel (IECN) | Un probl\`eme de type Yamabe sur les vari\'et\'es compactes spinorielles
compactes | null | Comptes Rendus de l Acad\'emie des Sciences - Series I -
Mathematics 338, 12 (2004) 929-934 | null | null | math.DG | null | Let $(M,g,\si)$ be a compact spin manifold of dimension $n \geq 2$. Let
$\lambda_1^+(\tilde{g})$ be the smallest positive eigenvalue of the Dirac
operator in the metric $\tilde{g} \in [g]$ conformal to $g$. We then define
$\lamin(M,[g],\si) = \inf_{\tilde{g} \in [g]} \lambda_1^+(\tilde{g})
\Vol(M,\tilde{g})^{1/n} $. We show that $0< \lamin(M,[g],\si) \leq
\lamin(\mS^n)$. %=\frac{n}{2} \om_n^{{1 \over n}}$ . We find sufficient
conditions for which we obtain strict inequality $\lamin(M,[g],\si) <
\lamin(\mS^n)$. This strict inequality has applications to conformal spin
geometry.
-----
Soit $(M,g,\si)$ une vari\'et\'e spinorielle compacte de dimension $n \geq
2$. %Si $\tilde{g} \in [g]$ est une m\'etrique conforme \`a $g$, On note
$\lambda_1^+(\tilde{g})$ la plus petite valeur propre $>0$ de l'op\'erateur de
Dirac dans la m\'etrique $\tilde{g} \in [g]$ conforme \`a $g$. On d\'efinit
$\lamin(M,[g],\si) = \inf_{\tilde{g} \in [g]} \lambda_1^+(\tilde{g})
\Vol(M,\tilde{g})^{1/n} $. On montre que $0< \lamin(M,[g],\si) \leq
\lamin(\mS^n)$. %= \frac{n}{2} \om_n^{{1 \over n}}$ On trouve des conditions
suffisantes pour lesquelles on obtient l'in\'egalit\'e stricte
$\lamin(M,[g],\si) < \lamin(\mS^n)$. Cette in\'egalit\'e stricte a des
applications en g\'eom\'etrie spinorielle conforme.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 18:48:34 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Dec 2007 16:26:36 GMT"
}
] | 2007-12-10T00:00:00 | [
[
"Ammann",
"Bernd",
"",
"IECN"
],
[
"Humbert",
"Emmanuel",
"",
"IECN"
],
[
"Morel",
"Bertrand",
"",
"IECN"
]
] |
0705.2758 | Felipe Barra | Felipe Barra and Thomas Gilbert | Steady-state conduction in self-similar billiards | null | Physical Review Letters vol, 98, 130601 (2007) | 10.1103/PhysRevLett.98.130601 | null | nlin.CD | null | The self-similar Lorentz billiard channel is a spatially extended
deterministic dynamical system which consists of an infinite one-dimensional
sequence of cells whose sizes increase monotonically according to their
indices. This special geometry induces a nonequilibrium stationary state with
particles flowing steadily from the small to the large scales. The
corresponding invariant measure has fractal properties reflected by the
phase-space contraction rate of the dynamics restricted to a single cell with
appropriate boundary conditions. In the near-equilibrium limit, we find
numerical agreement between this quantity and the entropy production rate as
specified by thermodynamics.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:10:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Barra",
"Felipe",
""
],
[
"Gilbert",
"Thomas",
""
]
] |
0705.2759 | Vasile Topor Pop N | V. Topor Pop, J. Barrette, C. Gale, S. Jeon (McGill Univ., Canada), M.
Gyulassy (Columbia Univ.NY, USA and FIAS, Frankfurt am Main, Germany) | Stopping Power from SPS to LHC energies | 3 pages, 2 figures, submitted to the CERN Theory Institute Workshop,
Heavy Ion Collisions at the LHC. Last Call Predictions, May 14 - June 8, 2007 | null | null | null | hep-ph | null | We investigate the energy dependence of hadron production and of stopping
power based on HIJING/BBbar v2.0 model calculations. Pseudorapidity spectra and
transverse momentum distributions for produced charged particles as well as net
baryons (per pair of partcipants) and their rapidity loss are compared to data
at RHIC and predictions for LHC energies are discussed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:16:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pop",
"V. Topor",
"",
"McGill Univ., Canada"
],
[
"Barrette",
"J.",
"",
"McGill Univ., Canada"
],
[
"Gale",
"C.",
"",
"McGill Univ., Canada"
],
[
"Jeon",
"S.",
"",
"McGill Univ., Canada"
],
[
"Gyulassy",
"M.",
"",
"Columbia Univ.NY, USA and FIAS, Frankfurt am Main, Germany"
]
] |
0705.2760 | John Cairns | John A. Cairns | Developing the Theory of Flux Limits from $\gamma$-Ray Cascades | 16 pages, 7 figures | null | null | null | astro-ph | null | Dark matter annihilation and other processes may precipitate a flux of
diffuse ultra-high energy $\gamma$-rays. These $\gamma$-rays may be observable
in present day experiments which observe diffuse fluxes at the GeV scale. Yet
the universe is presently opaque to $\gamma$-rays above 10 TeV. It is generally
assumed that cascade radiation is observable at all high energies, however the
disparity in energy from production to observation has important consequences
for theoretical flux limits. We detail the physics of cascade radiation
development and consider the influence of energy and redshift scale on
arbitrary flux limits that result from electromagnetic cascade.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:21:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cairns",
"John A.",
""
]
] |
0705.2761 | Vladimir Gubernov | V. V. Gubernov, H. S. Sidhu, G. N. Mercer | Combustion waves in a model with chain branching reaction and their
stability | pages 32, figures 23 | null | 10.1080/13647830701716948 | null | nlin.PS | null | In this paper the travelling wave solutions in the adiabatic model with
two-step chain branching reaction mechanism are investigated both numerically
and analytically in the limit of equal diffusivity of reactant, radicals and
heat. The properties of these solutions and their stability are investigated in
detail. The behaviour of combustion waves are demonstrated to have similarities
with the properties of nonadiabatic one-step combustion waves in that there is
a residual amount of fuel left behind the travelling waves and the solutions
can exhibit extinction. The difference between the nonadiabatic one-step and
adiabatic two-step models is found in the behaviour of the combustion waves
near the extinction condition. It is shown that the flame velocity drops down
to zero and a standing combustion wave is formed as the extinction condition is
reached. Prospects of further work are also discussed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:23:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gubernov",
"V. V.",
""
],
[
"Sidhu",
"H. S.",
""
],
[
"Mercer",
"G. N.",
""
]
] |
0705.2762 | Dennis Dieks | Dennis Dieks and Sander Lam | Complementarity in the Bohr-Einstein Photon Box | null | null | null | null | physics.hist-ph physics.gen-ph | null | The photon box thought experiment can be considered a forerunner of the
EPR-experiment: by performing suitable measurements on the box it is possible
to ``prepare'' the photon, long after it has escaped, in either of two
complementary states. Consistency requires that the corresponding box
measurements be complementary as well. At first sight it seems, however, that
these measurements can be jointly performed with arbitrary precision: they
pertain to different systems (the center of mass of the box and an internal
clock, respectively). But this is deceptive. As we show by explicit
calculation, although the relevant quantities are simultaneously measurable,
they develop non-vanishing commutators when calculated back to the time of
escape of the photon. This justifies Bohr's qualitative arguments in a precise
way; and it illustrates how the details of the dynamics conspire to guarantee
the requirements of complementarity. In addition, our calculations exhibit a
``fine structure'' in the distribution of the uncertainties over the
complementary quantities: depending on \textit{when} the box measurement is
performed, the resulting quantum description of the photon differs. This brings
us close to the argumentation of the later EPR thought experiment.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:32:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Dieks",
"Dennis",
""
],
[
"Lam",
"Sander",
""
]
] |
0705.2763 | Carsten Held | Carsten Held | Axiom System and Completeness Expression for Quantum Mechanics | 20 pages, no figures | Found. Phys. 38: 707-732, 2008 | 10.1007/s10701-008-9230-4 | null | quant-ph | null | The standard axiomatization of quantum mechanics (QM) is not fully explicit
about the role of the time-parameter. Especially, the time reference within the
probability algorithm (the Born Rule, BR) is unclear. Using a plausible
principle P1, about the role of probability in a physical theory, and a second
principle P2 affording a most natural way to make BR precise, a logical
conflict with the standard expression for the completeness of QM can be
derived. Rejecting P1 is implausible. Rejecting P2 leads to unphysical results
and to a conflict with a generalization of P2, a principle P3. It is thus made
plausible that the standard expression of QM completeness must be revised. An
absolutely explicit form of the axioms is provided, including a precise form of
the projection postulate. An appropriate expression for QM completeness,
reflecting the restrictions of the Gleason and Kochen-Specker theorems is
proposed.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:42:12 GMT"
},
{
"version": "v2",
"created": "Fri, 25 May 2007 16:11:19 GMT"
}
] | 2009-02-19T00:00:00 | [
[
"Held",
"Carsten",
""
]
] |
0705.2764 | Dennis Dieks | Dennis Dieks and Sander Lam | Complementarity in the Einstein-Bohr Photon Box | null | null | 10.1119/1.2919740 | null | quant-ph | null | The photon box thought experiment can be considered a forerunner of the
EPR-experiment: by performing suitable measurements on the box it is possible
to ``prepare'' the photon, long after it has escaped, in either of two
complementary states. Consistency requires that the corresponding box
measurements be complementary as well. At first sight it seems, however, that
these measurements can be jointly performed with arbitrary precision: they
pertain to different systems (the center of mass of the box and an internal
clock, respectively). But this is deceptive. As we show by explicit
calculation, although the relevant quantities are simultaneously measurable,
they develop non-vanishing commutators when calculated back to the time of
escape of the photon. This justifies Bohr's qualitative arguments in a precise
way; and it illustrates how the details of the dynamics conspire to guarantee
the requirements of complementarity. In addition, our calculations exhibit a
``fine structure'' in the distribution of the uncertainties over the
complementary quantities: depending on when the box measurement is performed,
the resulting quantum description of the photon differs. This brings us close
to the argumentation of the later EPR thought experiment.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:42:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dieks",
"Dennis",
""
],
[
"Lam",
"Sander",
""
]
] |
0705.2765 | Rustem Takhanov | Rustem Takhanov | On the monotonization of the training set | 10 pages | null | null | null | cs.LG cs.AI | null | We consider the problem of minimal correction of the training set to make it
consistent with monotonic constraints. This problem arises during analysis of
data sets via techniques that require monotone data. We show that this problem
is NP-hard in general and is equivalent to finding a maximal independent set in
special orgraphs. Practically important cases of that problem considered in
detail. These are the cases when a partial order given on the replies set is a
total order or has a dimension 2. We show that the second case can be reduced
to maximization of a quadratic convex function on a convex set. For this case
we construct an approximate polynomial algorithm based on convex optimization.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:44:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Takhanov",
"Rustem",
""
]
] |
0705.2766 | Albert Roura | C. H. Fleming, B. L. Hu, Albert Roura | Solutions to Master Equations of Quantum Brownian Motion in a General
Environment with External Force | 48 pages, 9 figures, REVTeX4 | null | null | LA-UR 06-8834 | quant-ph | null | We revisit the model of a system made up of a Brownian quantum oscillator
under the influence of an external classical force and linearly coupled to an
environment made up of many quantum oscillators at zero or finite temperature.
We show that the HPZ master equation for the reduced density matrix derived
earlier [B.L. Hu, J.P. Paz, Y. Zhang, Phys. Rev. D 45, 2843 (1992)] with
coefficients obtained from solutions of integro-differential equations can
assume closed functional forms for a fairly general class of spectral densities
of the environment at arbitrary temperature and coupling strength. As an
illustration of these new results we solve the corresponding master equation
and calculate, among other physical quantities, the uncertainty function whose
late time behavior can be obtained fully. This produces a formula for
investigating the standard quantum limit which is central to addressing many
theoretical issues in macroscopic quantum phenomena and experimental concerns
related to low temperature precision measurements. We find that any initial
state always settles down to a Gaussian density matrix whose covariance is
determined by the thermal reservoir and whose mean is determined by the
external force. For more general spectra we show that the solution of the
master equation can be reduced to solving for the motion of a classical
parametric oscillator with parametric frequency determined by the unsolved for
master equation coefficients. States in these systems experience evolution that
is parametrically similar to the simpler evolution explicitly determined for in
the case of Laurent-series spectra.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:52:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fleming",
"C. H.",
""
],
[
"Hu",
"B. L.",
""
],
[
"Roura",
"Albert",
""
]
] |
0705.2767 | John Singleton | Pei-Chun Ho, J. Singleton, M.B. Maple, Hisatomo Harima, P.A. Goddard,
Z. Henkie and A. Pietraszko | A de Haas-van Alphen study of the filled skutterudite compounds
PrOs$_4$As$_{12}$ and LaOs$_4$As$_{12}$ | null | null | 10.1088/1367-2630/9/8/269 | null | cond-mat.str-el cond-mat.supr-con | null | Comprehensive magnetic-field-orientation dependent studies of the
susceptibility and de Haas-van Alphen effect have been carried out on single
crystals of the filled skutterudites PrOs$_4$As$_{12}$ and LaOs$_4$As$_{12}$
using magnetic fields of up to 40~T. Several peaks are observed in the
low-field susceptibility of PrOs$_4$As$_{12}$, corresponding to cascades of
metamagnetic transitions separating the low-field antiferromagnetic and
high-field paramagnetic metal (PMM) phases. The de Haas-van Alphen experiments
show that the Fermi-surface topologies of PrOs$_4$As$_{12}$ in its PMM phase
and LaOs$_4$As$_{12}$ are very similar. In addition, they are in reasonable
agreement with the predictions of bandstructure calculations for
LaOs$_4$As$_{12}$ on the PrOs$_4$As$_{12}$ lattice. Both observations suggest
that the Pr 4$f$ electrons contribute little to the number of itinerant
quasiparticles in the PMM phase. However, whilst the properties of
LaOs$_4$As$_{12}$ suggest a conventional nonmagnetic Fermi liquid, the effects
of direct exchange and electron correlations are detected in the PMM phase of
PrOs$_4$As$_{12}$. For example, the quasiparticle effective masses in
PrOs$_4$As$_{12}$ are found to decrease with increasing field, probably
reflecting the gradual suppression of magnetic fluctuations associated with
proximity to the low-temperature, low-field antiferromagnetic state.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 19:56:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ho",
"Pei-Chun",
""
],
[
"Singleton",
"J.",
""
],
[
"Maple",
"M. B.",
""
],
[
"Harima",
"Hisatomo",
""
],
[
"Goddard",
"P. A.",
""
],
[
"Henkie",
"Z.",
""
],
[
"Pietraszko",
"A.",
""
]
] |
0705.2768 | Joe Polchinski | Nima Arkani-Hamed, Jacopo Orgera, Joseph Polchinski | Euclidean Wormholes in String Theory | 18 pages. ver. 2: typos corrected, references added | JHEP 0712:018,2007 | 10.1088/1126-6708/2007/12/018 | null | hep-th | null | We show that toroidal compactification of type II string theory to six
dimensions admits axionic euclidean wormhole solutions. These wormholes can be
inserted into $AdS_3 \times S^3 \times T^4$ backgrounds, which have a
well-defined CFT dual. AdS/CFT duality then suggests that the wormhole
solutions cannot be interpreted using $\alpha$ parameters as originally
suggested by Coleman.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:00:42 GMT"
},
{
"version": "v2",
"created": "Mon, 27 Aug 2007 21:42:13 GMT"
}
] | 2009-04-22T00:00:00 | [
[
"Arkani-Hamed",
"Nima",
""
],
[
"Orgera",
"Jacopo",
""
],
[
"Polchinski",
"Joseph",
""
]
] |
0705.2769 | Jonathan M. Link | C. Grieb, J. M. Link, M. L. Pitt, R. S. Raghavan, D. Rountree and R.
B. Vogelaar | LENS as a Probe of Sterile Neutrino Mediated Oscillations | Submitted to the proceedings of the XII International Workshop on
Neutrino Telescopes, March 6-9, 2007, Venice | null | null | null | hep-ex nucl-ex | null | Sterile neutrino ($\nu_s$) conversion in meter scale baselines can be
sensitively probed using mono-energetic, sub-MeV, flavor pure $\nu_e$'s from an
artificial MCi source and the unique technology of the LENS low energy solar
$\nu_e$ detector. Active-sterile {\em oscillations} can be directly observed in
the granular LENS detector itself to critically test and extend results of
short baseline accelerator and reactor experiments.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:02:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Grieb",
"C.",
""
],
[
"Link",
"J. M.",
""
],
[
"Pitt",
"M. L.",
""
],
[
"Raghavan",
"R. S.",
""
],
[
"Rountree",
"D.",
""
],
[
"Vogelaar",
"R. B.",
""
]
] |
0705.2770 | Gouranga Nayak | Gouranga C. Nayak (SUNY, Stony Brook) | Schwinger Mechanism for Quark-Antiquark Production in the Presence of
Arbitrary Time Dependent Chromo-Electric Field | 9 pages latex; Final Published Version in Electron.J.Theor.Phys | Electron.J.Theor.Phys.8:279-286,2011 | null | YITP-SB-07-19 | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the Schwinger mechanism in QCD in the presence of an arbitrary
time-dependent chromo-electric background field $E^a(t)$ with arbitrary color
index $a$=1,2,...8 in SU(3). We obtain an exact result for the non-perturbative
quark (antiquark) production from an arbitrary $E^a(t)$ by directly evaluating
the path integral. We find that the exact result is independent of all the time
derivatives $\frac{d^nE^a(t)}{dt^n}$ where $n=1,2,...\infty$. This result has
the same functional dependence on two Casimir invariants $[E^a(t)E^a(t)]$ and
$[d_{abc}E^a(t)E^b(t)E^c(t)]^2$ as the constant chromo-electric field $E^a$
result with the replacement: $E^a \rightarrow E^a(t)$. This result relies
crucially on the validity of the shift conjecture, which has not yet been
established.
| [
{
"version": "v1",
"created": "Mon, 21 May 2007 19:33:06 GMT"
},
{
"version": "v2",
"created": "Tue, 22 May 2007 18:34:49 GMT"
},
{
"version": "v3",
"created": "Mon, 23 May 2011 23:49:33 GMT"
}
] | 2011-06-09T00:00:00 | [
[
"Nayak",
"Gouranga C.",
"",
"SUNY, Stony Brook"
]
] |
0705.2771 | David Vegh | Agostino Butti, Davide Forcella, Amihay Hanany, David Vegh, Alberto
Zaffaroni | Counting Chiral Operators in Quiver Gauge Theories | 75 pages, 22 figures | JHEP 0711:092,2007 | 10.1088/1126-6708/2007/11/092 | Bicocca-FT-07-07, SISSA 25/2007/EP, MIT-CTP-3837, LPTENS 07/19 | hep-th | null | We discuss in detail the problem of counting BPS gauge invariant operators in
the chiral ring of quiver gauge theories living on D-branes probing generic
toric CY singularities. The computation of generating functions that include
counting of baryonic operators is based on a relation between the baryonic
charges in field theory and the Kaehler moduli of the CY singularities. A study
of the interplay between gauge theory and geometry shows that given geometrical
sectors appear more than once in the field theory, leading to a notion of
"multiplicities". We explain in detail how to decompose the generating function
for one D-brane into different sectors and how to compute their relevant
multiplicities by introducing geometric and anomalous baryonic charges. The
Plethystic Exponential remains a major tool for passing from one D-brane to
arbitrary number of D-branes. Explicit formulae are given for few examples,
including C^3/Z_3, F_0, and dP_1.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:03:32 GMT"
}
] | 2009-04-22T00:00:00 | [
[
"Butti",
"Agostino",
""
],
[
"Forcella",
"Davide",
""
],
[
"Hanany",
"Amihay",
""
],
[
"Vegh",
"David",
""
],
[
"Zaffaroni",
"Alberto",
""
]
] |
0705.2772 | Yangsen Yao | Yangsen Yao, Q. Daniel Wang | The Galactic Central Diffuse X-ray Enhancement: A Differential
Absorption/Emission Analysis | 5 pages, 4 figs, and 2 tables, accepted for publication in ApJ;
references updated; match to the version of proofs | null | null | null | astro-ph | null | The soft X-ray background shows a general enhancement toward the inner region
of the Galaxy. But whether this enhancement is a local feature (e.g., a
superbubble within a distance of <= 200 pc) and/or a phenomenon related to
energetic outflows from the Galactic center/bulge remains unclear. Here we
report a comparative X-ray emission and absorption study of diffuse hot gas
along the sight lines toward 3C 273 and Mrk 421, on and off the enhancement,
but at similar Galactic latitudes. The diffuse 3/4-keV emission intensity, as
estimated from the ROSAT All Sky Survey, is about three times higher toward 3C
273 than toward Mrk 421. Based on archival \chandra grating observations of
these two AGNs, we detect X-ray absorption lines (e.g., OVII Kalpha, Kbeta, and
OVIII Kalpha transitions at z~0) and find that the mean hot gas thermal and
kinematic properties along the two sight lines are significantly different. By
subtracting the foreground and background contribution, as determined along the
Mrk 421 sight line, we isolate the net X-ray absorption and emission produced
by the hot gas associated with the enhancement in the direction of 3C 273. From
a joint analysis of these differential data sets, we obtain the temperature,
dispersion velocity, and hydrogen column density as 2.0(1.6, 2.3)E6 K,
216(104,480) km/s, and 2.2(1.4, 4.1)E19 cm^{-2}, respectively (90% confidence
intervals), assuming that the gas is approximately isothermal, solar in metal
abundances, and equilibrium in collisional ionization. We also constrain the
effective line-of-sight extent of the gas to be 3.4(1.0, 10.1) kpc, strongly
suggesting that the enhancement most likely represents a Galactic central
phenomenon.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:04:23 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Jul 2007 03:18:28 GMT"
}
] | 2007-07-26T00:00:00 | [
[
"Yao",
"Yangsen",
""
],
[
"Wang",
"Q. Daniel",
""
]
] |
0705.2773 | Charles Kerton | C. R. Kerton | A sharper view of the outer Galaxy at 1420 and 408 MHz from the Canadian
Galactic Plane Survey - I. Revisiting the KR catalogue and new Gigahertz
Peaked Spectrum Sources | 10 pages, 9 figures | Mon.Not.Roy.Astron.Soc.373:1203,2006 | 10.1111/j.1365-2966.2006.11102.x | null | astro-ph | null | Arcminute-resolution radio continuum images at 408 and 1420 MHz from the
Canadian Galactic Plane Survey (CGPS) have been used to reexamine radio sources
listed in the Kallas and Reich (1980) catalogue. This catalogue is of
particular interest to Galactic studies as it lists both extended and compact
radio sources found in the second Galactic quadrant. We have determined the
nature (extended vs. compact, Galactic vs. extragalactic) of all of these
bright radio sources. A number of large HII regions with no optical
counterparts are highlighted along with a sample of large radio galaxies. Many
sources previously thought to be extended Galactic objects are shown to be
point sources. A sample of point sources with flat or rising spectra between
408 and 1420 MHz has been compiled, and within this sample likely Gigahertz
Peaked Spectrum sources have been identified.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:07:26 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kerton",
"C. R.",
""
]
] |
0705.2774 | Brandon C. Kelly | Brandon C. Kelly | Some Aspects of Measurement Error in Linear Regression of Astronomical
Data | 39 pages, 11 figures, 1 table, accepted by ApJ. IDL routines
(linmix_err.pro) for performing the Markov Chain Monte Carlo are available at
the IDL astronomy user's library, http://idlastro.gsfc.nasa.gov/homepage.html | Astrophys.J.665:1489-1506,2007 | 10.1086/519947 | null | astro-ph | null | I describe a Bayesian method to account for measurement errors in linear
regression of astronomical data. The method allows for heteroscedastic and
possibly correlated measurement errors, and intrinsic scatter in the regression
relationship. The method is based on deriving a likelihood function for the
measured data, and I focus on the case when the intrinsic distribution of the
independent variables can be approximated using a mixture of Gaussians. I
generalize the method to incorporate multiple independent variables,
non-detections, and selection effects (e.g., Malmquist bias). A Gibbs sampler
is described for simulating random draws from the probability distribution of
the parameters, given the observed data. I use simulation to compare the method
with other common estimators. The simulations illustrate that the Gaussian
mixture model outperforms other common estimators and can effectively give
constraints on the regression parameters, even when the measurement errors
dominate the observed scatter, source detection fraction is low, or the
intrinsic distribution of the independent variables is not a mixture of
Gaussians. I conclude by using this method to fit the X-ray spectral slope as a
function of Eddington ratio using a sample of 39 z < 0.8 radio-quiet quasars. I
confirm the correlation seen by other authors between the radio-quiet quasar
X-ray spectral slope and the Eddington ratio, where the X-ray spectral slope
softens as the Eddington ratio increases.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:27:02 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kelly",
"Brandon C.",
""
]
] |
0705.2775 | A. M. Fedotov | Alexander M. Fedotov, Konstantin Yu. Korolev and Maxim V. Legkov | Exact analytical expression for the electromagnetic field in a focused
laser beam or pulse | 10 pages, 4 figures, an extended version of the talk at the
International Conference on Coherent and Nonlinear Optics (ICONO 2007) | SPIE Proceedings Vol. 6726, 672613 (2007). | 10.1117/12.751772 | null | physics.optics physics.gen-ph | null | We present a new class of exact nonsingular solutions for the Maxwell
equations in vacuum, which describe the electromagnetic field of the
counterpropagating focused laser beams and the subperiod focused laser pulse.
These solutions are derived by the use of a modification of the "complex source
method", investigated and visualized.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:28:20 GMT"
}
] | 2007-09-17T00:00:00 | [
[
"Fedotov",
"Alexander M.",
""
],
[
"Korolev",
"Konstantin Yu.",
""
],
[
"Legkov",
"Maxim V.",
""
]
] |
0705.2776 | Oleg Verkhodanov | O. V. Verkhodanov (1), Yu. N. Parijskij (1), A. A. Starobinsky (2)
((1)Special Astrophysical Observatory, Nizhnij Arkhyz, Karachaj-Cherkesia,
Russia; (2) Landau Institute of Theoretical Physics, Moscow) | Determination of \Omega_\Lambda and H_0 from photometric data of radio
galaxies | 11 pages, 8 figures | Bull.Spec.Astrophys.Obs.N.Caucasus 58:5-15,2005 | null | null | astro-ph | null | From photometric observations of elliptical galaxies, among which are both
radio galaxies and radio-quiet objects, an investigation was carried out of the
relationship `redshift -- age of the stellar system' $(\Delta z/\Delta t)$. By
means of this relationship cosmological parameters $H(z)$ and $\Omega_\Lambda$
are estimated. Ages of stellar systems are determined within the framework of
evolution models of synthetic spectra PEGASE and GISSEL. This approach can be
considered as time study of objects of the early Universe independent of other
cosmological models. Construction of a pooled sample is described, containing
220 objects from different populations of elliptical galaxies, for which an
analysis of the upper limit of the age of formation of a stellar system was
performed. These data were used to estimate the boundaries of determination of
the cosmological parameters $H_0$ and $\Lambda$--term: $H_0=72\pm10$ and
$\Omega_\Lambda=0.8\pm0.1$ in the model GISSEL and $H_0=53\pm10$, and
$\Omega_\Lambda=0.8\pm0.1$ in the model PEGASE.
| [
{
"version": "v1",
"created": "Mon, 21 May 2007 12:45:54 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Verkhodanov",
"O. V.",
""
],
[
"Parijskij",
"Yu. N.",
""
],
[
"Starobinsky",
"A. A.",
""
]
] |
0705.2777 | Vitor Cardoso | Vitor Cardoso, Oscar J. C. Dias, Leonardo Gualtieri | The return of the membrane paradigm? Black holes and strings in the
water tap | This essay received an honorable mention in the Gravity Research
Foundation Essay Competition, 2007. v2: Published version | Int.J.Mod.Phys.D17:505-511,2008 | 10.1142/S0218271808012176 | null | hep-th gr-qc hep-ph physics.flu-dyn | null | Several general arguments indicate that the event horizon behaves as a
stretched membrane. We propose using this relation to understand gravity and
dynamics of black objects in higher dimensions. We provide evidence that (i)
the gravitational Gregory-Laflamme instability has a classical counterpart in
the Rayleigh-Plateau instability of fluids. Each known feature of the
gravitational instability can be accounted for in the fluid model. These
features include threshold mode, dispersion relation, time evolution and
critical dimension of certain phase transitions. Thus, we argue that black
strings break in much the same way as water from a faucet breaks up into small
droplets. (ii) General rotating black holes can also be understood with this
analogy. In particular, instability and bifurcation diagrams for black objects
can easily be inferred. This correspondence can and should be used as a guiding
tool to understand and explore physics of gravity in higher dimensions.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:34:57 GMT"
},
{
"version": "v2",
"created": "Fri, 16 May 2008 11:30:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cardoso",
"Vitor",
""
],
[
"Dias",
"Oscar J. C.",
""
],
[
"Gualtieri",
"Leonardo",
""
]
] |
0705.2778 | Jos\'e M. Figueroa-O'Farrill | Jos\'e Figueroa-O'Farrill, Jan Gutowski and Wafic Sabra | The return of the four- and five-dimensional preons | 10 pages (a minor imprecision has been corrected) | Class.Quant.Grav.24:4429-4438,2007 | 10.1088/0264-9381/24/17/010 | EMPG-07-08 | hep-th | null | We prove the existence of 3/4-BPS preons in four- and five-dimensional gauged
supergravities by explicitly constructing them as smooth quotients of the AdS_4
and AdS_5 maximally supersymmetric backgrounds, respectively. This result
illustrates how the spacetime topology resurrects a fraction of supersymmetry
previously ruled out by the local analysis of the Killing spinor equations.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 20:52:49 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 14:26:03 GMT"
},
{
"version": "v3",
"created": "Thu, 19 Jul 2007 18:41:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Figueroa-O'Farrill",
"José",
""
],
[
"Gutowski",
"Jan",
""
],
[
"Sabra",
"Wafic",
""
]
] |
0705.2779 | Charles Kerton | C. R. Kerton, J. Murphy, and J. Patterson | A sharper view of the outer Galaxy at 1420 and 408 MHz from the Canadian
Galactic Plane Survey II: The catalogue of extended radio sources | accepted for publication in MNRAS, 8 pages, 6 figures | Mon.Not.Roy.Astron.Soc.379:289-296,2007 | 10.1111/j.1365-2966.2007.11945.x | null | astro-ph | null | A new catalogue of extended radio sources has been prepared based on
arcminute-resolution 1420 MHz images from the Canadian Galactic Plane Survey
(CGPS). The new catalogue provides both 1420 MHz and 408 MHz flux density
measurements on sources found near the Galactic plane in the second quadrant of
our Galaxy. In addition cross-identifications are made with other major radio
catalogues and information is provided to facilitate the recovery of CGPS image
data associated with each catalogued source. Numerous new radio sources are
identified and the catalogue provides a comprehensive summary of both newly
discovered and previously known HII regions and supernova remnants in the outer
Galaxy. The catalogue should be of use both for synoptic studies of Galactic
structure and for placing higher resolution observations, at radio and other
wavelengths, in context.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 21:04:56 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kerton",
"C. R.",
""
],
[
"Murphy",
"J.",
""
],
[
"Patterson",
"J.",
""
]
] |
0705.2780 | Ying Liu | Y. Liu, W. B. Manchester IV, J. C. Kasper, J. D. Richardson, and J. W.
Belcher | Determining the Magnetic Field Orientation of Coronal Mass Ejections
from Faraday Rotation | 22 pages with 9 figures, accepted for publication in Astrophys. J | Astrophys.J.665:1439-1447, 2007 | 10.1086/520038 | null | astro-ph | null | We describe a method to measure the magnetic field orientation of coronal
mass ejections (CMEs) using Faraday rotation (FR). Two basic FR profiles,
Gaussian-shaped with a single polarity or "N"-like with polarity reversals, are
produced by a radio source occulted by a moving flux rope depending on its
orientation. These curves are consistent with the Helios observations,
providing evidence for the flux-rope geometry of CMEs. Many background radio
sources can map CMEs in FR onto the sky. We demonstrate with a simple flux rope
that the magnetic field orientation and helicity of the flux rope can be
determined 2-3 days before it reaches Earth, which is of crucial importance for
space weather forecasting. An FR calculation based on global
magnetohydrodynamic (MHD) simulations of CMEs in a background heliosphere shows
that FR mapping can also resolve a CME geometry curved back to the Sun. We
discuss implementation of the method using data from the Mileura Widefield
Array (MWA).
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 21:24:36 GMT"
}
] | 2010-11-11T00:00:00 | [
[
"Liu",
"Y.",
""
],
[
"Manchester",
"W. B.",
"IV"
],
[
"Kasper",
"J. C.",
""
],
[
"Richardson",
"J. D.",
""
],
[
"Belcher",
"J. W.",
""
]
] |
0705.2781 | Eric B. Ford | Eric B. Ford, Fred C. Adams, Phil Armitage, B. Scott Gaudi, Renu
Malhotra, Mathew J. Holman, Geoffrey W. Marcy, Frederic A. Rasio, Steinn
Sigurdsson | Role of Dynamical Research in the Detection and Characterization of
Exoplanets | 9 pages, White Paper Submitted to the ExoPlanet Task Force | null | null | null | astro-ph | null | (Abridged) The discovery of extrasolar planetary systems revealed an
unexpected diversity of planetary systems that has revolutionized planet
formation theory. A strong program of theoretical research is essential to
maximize both the discovery potential and the scientific returns of future
observational programs, so as to achieve a deeper understanding of the
formation and evolution of planetary systems. We outline three broad categories
of theoretical research: detailed studies of specific planetary systems,
testing planet formation models by comparing their predictions to the observed
exoplanet population, and detailed modeling of specific physical processes. We
describe how such theoretical research plays an important role in analyzing
observations for a wide range detection methods and contributes to
understanding the Earth's place in the universe and the potential for
Earth-like life beyond our solar system. In this white paper, we suggest how to
maximize the scientific return of future exoplanet observations. Our
recommendations include a strong theory program, support for multiple
observational programs that will study a diverse set of planets and stars,
significant observing time devoted to follow-up observations, and healthy
collaboration between observers and theorists.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 21:27:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ford",
"Eric B.",
""
],
[
"Adams",
"Fred C.",
""
],
[
"Armitage",
"Phil",
""
],
[
"Gaudi",
"B. Scott",
""
],
[
"Malhotra",
"Renu",
""
],
[
"Holman",
"Mathew J.",
""
],
[
"Marcy",
"Geoffrey W.",
""
],
[
"Rasio",
"Frederic A.",
""
],
[
"Sigurdsson",
"Steinn",
""
]
] |
0705.2782 | J. E. Thomas | Bason Clancy, Le Luo, and John E. Thomas | Observation of a quenched moment of inertia in a rotating strongly
interacting Fermi gas | 4 pages 5 figures | null | 10.1103/PhysRevLett.99.140401 | null | cond-mat.other | null | We make a model-independent measurement of the moment of inertia of a
rotating, expanding strongly-interacting Fermi gas. Quenching of the moment of
inertia is observed for energies both below and above the superfluid
transition. This shows that a strongly interacting Fermi gas with angular
momentum can support irrotational flow in both the superfluid and collisional
normal fluid regimes.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 21:28:49 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Clancy",
"Bason",
""
],
[
"Luo",
"Le",
""
],
[
"Thomas",
"John E.",
""
]
] |
0705.2783 | Ludovic Berthier | Ludovic Berthier | Revisiting the slow dynamics of a silica melt using Monte Carlo
simulations | 13 pages, 10 figures; to be published in Phys. Rev. E | Phys. Rev. E 76, 011507 (2007) | 10.1103/PhysRevE.76.011507 | null | cond-mat.dis-nn cond-mat.stat-mech | null | We implement a standard Monte Carlo algorithm to study the slow, equilibrium
dynamics of a silica melt in a wide temperature regime, from 6100 K down to
2750 K. We find that the average dynamical behaviour of the system is in
quantitative agreement with results obtained from molecular dynamics
simulations, at least in the long-time regime corresponding to the
alpha-relaxation. By contrast, the strong thermal vibrations related to the
Boson peak present at short times in molecular dynamics are efficiently
suppressed by the Monte Carlo algorithm. This allows us to reconsider silica
dynamics in the context of mode-coupling theory, because several shortcomings
of the theory were previously attributed to thermal vibrations. A mode-coupling
theory analysis of our data is qualitatively correct, but quantitative tests of
the theory fail, raising doubts about the very existence of an avoided
singularity in this system. We discuss the emergence of dynamic heterogeneity
and report detailed measurements of a decoupling between translational
diffusion and structural relaxation, and of a growing four-point dynamic
susceptibility. Dynamic heterogeneity appears to be less pronounced than in
more fragile glass-forming models, but not of a qualitatively different nature.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 22:06:24 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 13:38:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Berthier",
"Ludovic",
""
]
] |
0705.2784 | Andrew M. Childs | Andrew M. Childs, Leonard J. Schulman, Umesh V. Vazirani | Quantum algorithms for hidden nonlinear structures | 13 pages | Proc. 48th IEEE Symposium on Foundations of Computer Science (FOCS
2007), pp. 395-404 | 10.1109/FOCS.2007.18 | null | quant-ph | null | Attempts to find new quantum algorithms that outperform classical computation
have focused primarily on the nonabelian hidden subgroup problem, which
generalizes the central problem solved by Shor's factoring algorithm. We
suggest an alternative generalization, namely to problems of finding hidden
nonlinear structures over finite fields. We give examples of two such problems
that can be solved efficiently by a quantum computer, but not by a classical
computer. We also give some positive results on the quantum query complexity of
finding hidden nonlinear structures.
| [
{
"version": "v1",
"created": "Mon, 21 May 2007 18:31:12 GMT"
}
] | 2008-07-10T00:00:00 | [
[
"Childs",
"Andrew M.",
""
],
[
"Schulman",
"Leonard J.",
""
],
[
"Vazirani",
"Umesh V.",
""
]
] |
0705.2785 | Kevin Flood | Kevin Flood | Evidence for D0-D0bar Mixing at Babar | 6 pages, 4 figures; Submitted to the proceedings of the XLIInd
Rencontres de Moriond Electroweak Interactions and Unified Theories, March
10-17 2007, and the XLIInd Rencontres de Moriond QCD and Hadronic
Interactions, March 17-24 2007, La Thuile, Italy | null | null | null | hep-ex | null | We present evidence for D0-D0bar mixing in $D^0 \to K^{+}\pi^{-}$ decays from
384 fb^{-1} of e+e- colliding-beam data recorded near sqrt(s)=10.6 GeV with the
Babar detector at the PEP-II storage rings at SLAC. We find the mixing
parameters ${x^{\prime}}^2 = [-0.22 \pm 0.30 (stat.) \pm 0.21 (syst.)] \times
10^{-3}$ and $y^{\prime} = [9.7 \pm 4.4 (stat.) \pm 3.1 (syst.)] \times
10^{-3}$, and a correlation between them of -0.94. This result is inconsistent
with the no-mixing hypothesis with a significance of 3.9 standard deviations.
We measure $R_{\rm D}$, the ratio of doubly Cabibbo-suppressed to
Cabibbo-favored decay rates, to be $[0.303 \pm 0.016 (stat.) \pm 0.010 (syst.)]
%$. We find no evidence for CP violation.
| [
{
"version": "v1",
"created": "Fri, 18 May 2007 23:10:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Flood",
"Kevin",
""
]
] |
0705.2786 | Joachim Wlodarz | Joachim J. Wlodarz | Virtualization: A double-edged sword | null | null | null | null | cs.OS cs.CR | null | Virtualization became recently a hot topic once again, after being dormant
for more than twenty years. In the meantime, it has been almost forgotten, that
virtual machines are not so perfect isolating environments as it seems, when
looking at the principles. These lessons were already learnt earlier when the
first virtualized systems have been exposed to real life usage.
Contemporary virtualization software enables instant creation and destruction
of virtual machines on a host, live migration from one host to another,
execution history manipulation, etc. These features are very useful in
practice, but also causing headaches among security specialists, especially in
current hostile network environments.
In the present contribution we discuss the principles, potential benefits and
risks of virtualization in a deja vu perspective, related to previous
experiences with virtualization in the mainframe era.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 00:02:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Wlodarz",
"Joachim J.",
""
]
] |
0705.2787 | David Martin | David J. Martin, Daniel Kifer, Ashwin Machanavajjhala, Johannes
Gehrke, Joseph Y. Halpern | Worst-Case Background Knowledge for Privacy-Preserving Data Publishing | 10 pages | null | null | null | cs.DB | null | Recent work has shown the necessity of considering an attacker's background
knowledge when reasoning about privacy in data publishing. However, in
practice, the data publisher does not know what background knowledge the
attacker possesses. Thus, it is important to consider the worst-case. In this
paper, we initiate a formal study of worst-case background knowledge. We
propose a language that can express any background knowledge about the data. We
provide a polynomial time algorithm to measure the amount of disclosure of
sensitive information in the worst case, given that the attacker has at most a
specified number of pieces of information in this language. We also provide a
method to efficiently sanitize the data so that the amount of disclosure in the
worst case is less than a specified threshold.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 00:12:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Martin",
"David J.",
""
],
[
"Kifer",
"Daniel",
""
],
[
"Machanavajjhala",
"Ashwin",
""
],
[
"Gehrke",
"Johannes",
""
],
[
"Halpern",
"Joseph Y.",
""
]
] |
0705.2788 | Elizaveta Shabalina | D0 Collaboration, V. Abazov, et al | Measurement of the ttbar production cross section in ppbar collisions at
sqrt{s} = 1.96 TeV using kinematic characteristics of lepton + jets events | 24 pages, 17 figures, submitted to Phys. Rev. D | Phys.Rev.D76:092007,2007 | 10.1103/PhysRevD.76.092007 | FERMILAB-PUB-07/128-E | hep-ex | null | We present a measurement of the top quark pair production cross section in
ppbar collisions at sqrt(s)=1.96 TeV utilizing 425 pb-1 of data collected with
the D0 detector at the Fermilab Tevatron Collider. We consider the final state
of the top quark pair containing one high-pT electron or muon and at least four
jets. We exploit specific kinematic features of ttbar events to extract the
cross section. For a top quark mass of 175 GeV, we measure sigma_ttbar = 6.4
+1.3-1.2(stat} +/- 0.7(syst)+/- 0.4(lum) pb in good agreement with the standard
model prediction.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 00:44:05 GMT"
}
] | 2010-04-08T00:00:00 | [
[
"D0 Collaboration",
"",
""
],
[
"Abazov",
"V.",
""
]
] |
0705.2789 | Boris Ivlev | B. Ivlev | Euclidean resonance in a magnetic field | 7 pages, 4 figures | null | 10.1103/PhysRevA.76.022108 | null | quant-ph | null | An analogy between Wigner resonant tunneling and tunneling across a static
potential barrier in a static magnetic field is found. Whereas in the process
of Wigner tunneling an electron encounters a classically allowed regions, where
a discrete energy level coincides with its energy, in the magnetic field a
potential barrier is a constant in the direction of tunneling. Along the
tunneling path the certain regions are formed, where, in the classical
language, the kinetic energy of the motion perpendicular to tunneling is
negative. These regions play a role of potential wells, where a discrete energy
level can coincide with the electron energy. Such phenomenon, which occurs at
the certain magnetic field, is called Euclidean resonance and substantially
depends on a shape of potential forces in the direction perpendicular to
tunneling. Under conditions of Euclidean resonance a long distance underbarrier
motion is possible.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 00:48:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ivlev",
"B.",
""
]
] |
0705.2790 | Felipe Barra | Felipe Barra, Nikolai Chernov and Thomas Gilbert | Log-periodic drift oscillations in self-similar billiards | null | Nonlinearity vol 20, (2007) 2539-2549 | 10.1088/0951-7715/20/11/005 | null | nlin.CD | null | We study a particle moving at unit speed in a self-similar Lorentz billiard
channel; the latter consists of an infinite sequence of cells which are
identical in shape but growing exponentially in size, from left to right. We
present numerical computation of the drift term in this system and establish
the logarithmic periodicity of the corrections to the average drift.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 00:51:25 GMT"
}
] | 2009-08-29T00:00:00 | [
[
"Barra",
"Felipe",
""
],
[
"Chernov",
"Nikolai",
""
],
[
"Gilbert",
"Thomas",
""
]
] |
0705.2791 | Shunzo Kumano | M. Hirai, S. Kumano, T.-H. Nagai, and K. Sudoh | Global analysis for determining fragmentation functions and their
uncertainties in light hadrons | 4 pages, LaTeX, 6 eps files, to be published in proceedings of 42nd
Rencontres de Moriond on QCD and high energy hadronic interactions, La
Thuile, Italy, 17-24 Mar 2007. A code for calculating the fragmentation
functions and their uncertainties can be obtained from
http://research.kek.jp/people/kumanos/ffs.html | null | null | KEK-TH-1146 | hep-ph hep-ex nucl-ex nucl-th | null | Fragmentation functions are determined for the pion, kaon, and proton by
analyzing charged-hadron production data in electron-positron annihilation. It
is important that uncertainties of the determined fragmentation functions are
estimated in this analysis. Analysis results indicate that gluon and
light-quark functions have large uncertainties especially at small Q^2. We find
that next-to-leading-order (NLO) uncertainties are significantly reduced in
comparison with leading-order (LO) ones in the pion and kaon. The fragmentation
functions are very different in various analysis groups. However, all the
recent functions are roughly within the estimated uncertainties, which
indicates that they are consistent with each other. We provide a code for
calculating the fragmentation functions and their uncertainties at a given
kinematical point of z and Q^2 by a user.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 01:12:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hirai",
"M.",
""
],
[
"Kumano",
"S.",
""
],
[
"Nagai",
"T. -H.",
""
],
[
"Sudoh",
"K.",
""
]
] |
0705.2792 | Lei Qian | Siming Liu, Lei Qian, Xue-Bing Wu, Christopher L. Fryer and Hui Li | The Nature of Linearly Polarized Millimeter and Sub-millimeter Emission
in Sagittarius A* | With the new version accepted by ApJ Letter | null | 10.1086/522832 | null | astro-ph | null | The linearly polarized millimeter and sub-millimeter emission in Sagittarius
A* is produced within 10 Schwarzschild radii of the supermassive black hole at
the Galactic Center and may originate from a hot magnetized accretion disk,
where electrons are heated efficiently by turbulent plasma waves. In such a
scenario, the flux density and polarization are very sensitive to the electron
heating rate and the inclination angle of disk, respectively, and the major
axis of the sub-millimeter intrinsic polarization, which is aligned with the
rotation axis of the disk, is perpendicular to the major axis of the polarized
near-infrared emission. In combination with MHD simulations, which study the
properties of the magnetic field and viscous stresses, the current spectral and
polarization measurements give tight constraints on the model parameters.
Simultaneous observations will be able to test the model.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 01:14:06 GMT"
},
{
"version": "v2",
"created": "Thu, 30 Aug 2007 04:27:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Liu",
"Siming",
""
],
[
"Qian",
"Lei",
""
],
[
"Wu",
"Xue-Bing",
""
],
[
"Fryer",
"Christopher L.",
""
],
[
"Li",
"Hui",
""
]
] |
0705.2793 | Semen Kutateladze S | S.S. Kutateladze | Abstract Convexity and Cone-Vexing Abstractions | A talk for the workshop "Idempotent and Tropical Mathematics and
Problems of Mathematical Physics," Moscow, August 25-30, 2007 | null | null | null | math.FA math.OC | null | This talk is a write-up on some origins of abstract convexity and afew vexing
limitations on the range of abstraction in convexity.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 01:25:12 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kutateladze",
"S. S.",
""
]
] |
0705.2794 | Antonia Chimonidou Ms | Antonia Chimonidou and E.C.G. Sudarshan | Relaxation Phenomena in a System of Two Harmonic Oscillators | 22 pages, 6 Figures, Added contents, to appear in PRA | null | 10.1103/PhysRevA.77.032121 | null | quant-ph cond-mat.stat-mech | null | We study the process by which quantum correlations are created when an
interaction Hamiltonian is repeatedly applied to a system of two harmonic
oscillators for some characteristic time interval. We show that, for the case
where the oscillator frequencies are equal, the initial Maxwell-Boltzmann
distributions of the uncoupled parts evolve to a new equilibrium
Maxwell-Boltzmann distribution through a series of transient Maxwell-Boltzmann
distributions. Further, we discuss why the equilibrium reached when the two
oscillator frequencies are unequal, is not a thermal one. All the calculations
are exact and the results are obtained through an iterative process, without
using perturbation theory.
| [
{
"version": "v1",
"created": "Mon, 21 May 2007 01:36:53 GMT"
},
{
"version": "v2",
"created": "Wed, 23 May 2007 16:43:40 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Mar 2008 20:52:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chimonidou",
"Antonia",
""
],
[
"Sudarshan",
"E. C. G.",
""
]
] |
0705.2795 | Vasiliev Boris | B.V.Vasiliev | The comparison of theoretical predictions with measuring data of stellar
parameters | null | null | null | null | astro-ph | null | The Euler equation has been accepted as the basic postulate of stellar
physics long before the plasma physics was developed. The existence of
electrical interaction between particles of interstellar plasma poses the
question, how this interaction must be accounted for. We argue that the right
way is in formulation of a new postulate. On the base of the new postulate, the
theory of a hot star interior is developed. Using this theory we obtain the
distribution of stars over their masses and mass-radius, mass-temperature and
mass-luminosity dependencies. The theory of the apsidal rotation of binary
stars and the spectrum of solar oscillation is considered. All these
theoretical predictions are in a good agreement with the known measurement
data, which confirms the validity of this consideration.
| [
{
"version": "v1",
"created": "Mon, 21 May 2007 14:26:22 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Sep 2007 12:22:18 GMT"
}
] | 2007-09-11T00:00:00 | [
[
"Vasiliev",
"B. V.",
""
]
] |
0705.2796 | Hai Long Ma | Hai-Long Ma (For BES Collaboration) | Recent Results on non$-D\bar D$ decays of $\psi(3770)$ from BES | 4 pages, To appear in the proceedings of 42st Rencontres de Moriond
on QCD and Hadronic interactions, La Thuile, Aosta Valley, Italy, 17-24 Mar
2007 | null | null | null | hep-ex | null | BES Collaboration measured the $R$ values at 3.650, 3.6648 and 3.773 GeV, the
$R$ values at 68 energy points in the energy region between 3.650 and 3.872
GeV, the resonance parameters of $\psi(3686)$ and $\psi(3770)$, the branching
fractions for $\psi(3770)\to D^0\bar D^0, D^+D^-, D\bar D$ and non-$D\bar D$,
and the observed cross sections for some exclusive light hadron final states at
3.773 and 3.650 GeV. These measurements are made by analyzing the data sets
collected with the BESII detector at the BEPC collider.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 05:16:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ma",
"Hai-Long",
"",
"For BES Collaboration"
]
] |
0705.2797 | Ting-Wai Chiu | Ting-Wai Chiu, Tung-Han Hsieh, Chao-Hsi Huang, Kenji Ogawa (TWQCD
Collaboration) | Beauty mesons in lattice QCD with exact chiral symmetry | 12 pages | Phys.Lett.B651:171-176,2007 | 10.1016/j.physletb.2007.06.017 | NTUTH-07-505C | hep-lat hep-ex hep-ph | null | We present the first study of treating b, c, and s quarks as Dirac fermions
in lattice QCD with exact chiral symmetry. For 100 gauge configurations
generated with single-plaquette action at beta = 7.2 on the 32^3 x 60 lattice,
we compute point-to-point quark propagators for 33 quark masses in the range
0.01 < m_q a < 0.85, and measure the time-correlation function of
(pseudo-)scalar, (pseudo-)vector, and tensor mesons, for symmetric and
asymmetric quark masses respectively. The lowest-lying mass spectra of mesons
with quark contents b_bbar, c_bbar, s_bbar, and c_cbar are determined, together
with the pseudoscalar decay constants. Our results are sumarized in Tables 1-5.
Furthermore, we also determine the b and c quark masses in the MS_bar scheme,
m_b = 4.65(5) GeV, and m_c = 1.16(4) GeV.
| [
{
"version": "v1",
"created": "Sat, 19 May 2007 10:31:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chiu",
"Ting-Wai",
"",
"TWQCD\n Collaboration"
],
[
"Hsieh",
"Tung-Han",
"",
"TWQCD\n Collaboration"
],
[
"Huang",
"Chao-Hsi",
"",
"TWQCD\n Collaboration"
],
[
"Ogawa",
"Kenji",
"",
"TWQCD\n Collaboration"
]
] |
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