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list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0705.3398 | Markus Dahlem | Markus A. Dahlem, Felix M. Schneider, Eckehard Schoell | Efficient control of transient wave forms to prevent spreading
depolarizations | null | null | null | null | nlin.PS | null | In various neurological disorders spatio-temporal excitation patterns
constitute examples of excitable behavior emerging from pathological pathways.
During migraine, seizure, and stroke an initially localized pathological state
can temporarily spread indicating a transition from non-excitable to excitable
behavior. We investigate these transient wave forms in the generic
FitzHugh-Nagumo (FHN) system of excitable media. Our goal is to define an
efficient control minimizing the volume of invaded tissue. The general point of
such a therapeutic optimization is how to apply control theory in the framework
of structures in differential geometry by regarding parameter plane M of the
FHN system as a differential manifold endowed with a metric. We suggest to
equip M with a metric given by pharmacokinetic-pharmacodynamic models of drug
receptor interaction.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:31:26 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 11:27:04 GMT"
}
] | 2007-09-27T00:00:00 | [
[
"Dahlem",
"Markus A.",
""
],
[
"Schneider",
"Felix M.",
""
],
[
"Schoell",
"Eckehard",
""
]
] |
0705.3399 | Conca Aldo | Winfried Bruns, Aldo Conca | The variety of exterior powers of linear maps | Few minor changes. Final version to appear in J. of Algebra | null | null | null | math.AC math.AG | null | Let $K$ be a field and $V$ and $W$ be $K$-vector spaces of dimension $m$ and
$n$. Let $\phi$ be the canonical map from $Hom(V,W)$ to $Hom(\wedge^t
V,\wedge^t W)$. We investigate the Zariski closure $X_t$ of the image $Y_t$ of
$\phi$. In the case $t=\min(m,n)$, $Y_t=X_t$ is the cone over a Grassmannian,
but $X_t$ is larger than $Y_t$ for $1<t<\min(m,n)$. We analyze the
$G=\GL(V)\times\GL(W)$-orbits in $X_t$ via the corresponding $G$-stable prime
ideals. It turns out that they are classified by two numerical invariants, one
of which is the rank and the other a related invariant that we call small rank.
Surprisingly, the orbits in $X_t\setminus Y_t$ arise from the images $Y_u$ for
$u<t$ and simple algebraic operations. In the last section we determine the
singular locus of $X_t$. Apart from well-understood exceptional cases, it is
formed by the elements of rank $\le 1$ in $Y_t$.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:31:34 GMT"
},
{
"version": "v2",
"created": "Wed, 2 Apr 2008 09:32:32 GMT"
}
] | 2008-04-02T00:00:00 | [
[
"Bruns",
"Winfried",
""
],
[
"Conca",
"Aldo",
""
]
] |
0705.3400 | Dmitry Levko | Dmitry Levko | The method for solving the KdV-equation | 2 pages | null | null | null | nlin.PS nlin.SI | null | The method for solving the KdV are considered.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:43:18 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Levko",
"Dmitry",
""
]
] |
0705.3401 | Francesca D'Antona | F. D'Antona and P. Ventura | A model for the Globular Cluster extreme anomalies | 12 pages, 8 figures and 5 tables, accepted for publication in MNRAS | Mon.Not.Roy.Astron.Soc.379:1431-1441,2007 | 10.1111/j.1365-2966.2007.12019.x | null | astro-ph | null | In spite of the efforts made in the latest years, still there is no
comprehensive explanation for the chemical anomalies of globular cluster stars.
Among these, the most striking is oxygen depletion, which reaches values down
to [O/Fe]~-0.4 in most clusters, but in M13 it goes down to less than [O/Fe]~ -
1. In this work we suggest that the anomalies are due to the super position of
two different events: 1) PRIMORDIAL SELF-ENRICHMENT: this is asked to explain
the oxygen depletion down to a minimum value [O/Fe]~ -0.4; 2) EXTRA MIXING IN A
FRACTION OF THE STARS ALREADY BORN WITH ANOMALOUS COMPOSITION: these objects,
starting with already low [O/Fe], will reduce the oxygen abundance down to the
most extreme values. Contrary to other models that invoke extra mixing to
explain the chemical anomalies, we suggest that it is active only if there is a
fraction of the stars in which the primordial composition is not only oxygen
depleted, but also extremely helium rich (Y~ 0.4), as found in a few GCs from
their main sequence multiplicity. We propose that the rotational evolution (and
an associated extra mixing) of extremely helium rich stars may be affected by
the fact that they develop a very small or non existent molecular weight
barrier during the evolution. We show that extra mixing in these stars, having
initial chemistry that has already been CNO processed, affects mainly the
oxygen abundance, and to a much smaller extent if affects the sodium abundance.
The model also predicts a large fluorine depletion concomitant with the oxygen
depletion, and a further enhancement of the surface helium abundance, which
reaches values close to Y=0.5 in the computed models. We stress that, in this
tentative explanation, those stars that are primordially O--depleted, but ARE
NOT extremely helium rich do not suffer deep extra mixing.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:44:54 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"D'Antona",
"F.",
""
],
[
"Ventura",
"P.",
""
]
] |
0705.3402 | Vladislav Korenivski | R. Palm and V. Korenivski | A ferrofluid based neural network: design of an analogue associative
memory | submitted to Neural Networks | New J. Phys. 11 (2009) 023003 | 10.1088/1367-2630/11/2/023003 | null | cond-mat.dis-nn | null | We analyse an associative memory based on a ferrofluid, consisting of a
system of magnetic nano-particles suspended in a carrier fluid of variable
viscosity subject to patterns of magnetic fields from an array of input and
output magnetic pads. The association relies on forming patterns in the
ferrofluid during a trainingdphase, in which the magnetic dipoles are free to
move and rotate to minimize the total energy of the system. Once equilibrated
in energy for a given input-output magnetic field pattern-pair the particles
are fully or partially immobilized by cooling the carrier liquid. Thus produced
particle distributions control the memory states, which are read out
magnetically using spin-valve sensors incorporated in the output pads. The
actual memory consists of spin distributions that is dynamic in nature,
realized only in response to the input patterns that the system has been
trained for. Two training algorithms for storing multiple patterns are
investigated. Using Monte Carlo simulations of the physical system we
demonstrate that the device is capable of storing and recalling two sets of
images, each with an accuracy approaching 100%.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 12:40:02 GMT"
}
] | 2013-11-27T00:00:00 | [
[
"Palm",
"R.",
""
],
[
"Korenivski",
"V.",
""
]
] |
0705.3403 | Erik Elfgren | Erik Elfgren, Francois-Xavier D\'esert, and Bruno Guiderdoni | Dust Distribution during Reionization | 6 pages, 6 figures; Typos fixed. Clarifications in the abstract,
sections 2 and 4.1 and fig 6 | Astron.Astrophys.476:1145-1150,2007 | 10.1051/0004-6361:20053151 | null | astro-ph | null | The dust produced by the first generation of stars will be a foreground to
cosmic microwave background. In order to evaluate the effect of this early
dust, we calculate the power spectrum of the dust emission anisotropies and
compare it with the sensitivity limit of the Planck satellite. The spatial
distribution of the dust is estimated through the distribution of dark matter.
At small angular scales ($\ell \gtrsim 1000$) the dust signal is found to be
noticeable with the Planck detector for certain values of dust lifetime and
production rates. The dust signal is also compared to sensitivities of other
instruments. The early dust emission anisotropies are finally compared to those
of local dust and they are found to be similar in magnitude at mm wavelengths.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:50:23 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 14:14:29 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Elfgren",
"Erik",
""
],
[
"Désert",
"Francois-Xavier",
""
],
[
"Guiderdoni",
"Bruno",
""
]
] |
0705.3404 | Subhaneil Lahiri | Subhaneil Lahiri and Shiraz Minwalla | Plasmarings as dual black rings | 40 pages, 40 figures. (v2) Correction to black brane equation of
state, additional references | JHEP 0805:001,2008 | 10.1088/1126-6708/2008/05/001 | null | hep-th | null | We construct solutions to the relativistic Navier-Stokes equations that
describe the long wavelength collective dynamics of the deconfined plasma phase
of N=4 Yang Mills theory compactified down to d=3 on a Scherk-Schwarz circle
and higher dimensional generalisations. Our solutions are stationary, axially
symmetric spinning balls and rings of plasma. These solutions, which are dual
to (yet to be constructed) rotating black holes and black rings in
Scherk-Schwarz compactified AdS(5) and AdS(6), and have properties that are
qualitatively similar to those of black holes and black rings in flat five
dimensional supergravity.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:51:00 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Dec 2007 19:43:29 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Lahiri",
"Subhaneil",
""
],
[
"Minwalla",
"Shiraz",
""
]
] |
0705.3405 | Yu. G. Naidyuk | Yu. G. Naidyuk, O. E. Kvitnitskaya, I. K. Yanson, G. Fuchs, K. Nenkov,
A. Waelte, G. Behr, D. Souptel, and S.-L. Drechsler | Point-contact spectroscopy of the antiferromagnetic superconductor
HoNi2B2C in the normal and superconducting state | 11 pages, 8 figs, to be published in PRB, Vol.75, Iss.21 | Phys.Rev. B 76, 014520 (2007) | 10.1103/PhysRevB.76.014520 | null | cond-mat.supr-con | null | Point-contact (PC) spectroscopy measurements on antiferromagnetic (AF)
(T_N=5.2K) HoNi2B2C single crystals in the normal and two different
superconducting (SC) states (T_c=8.5K and $T_c^*=5.6K) are reported. The PC
study of the electron-boson(phonon) interaction (EB(P)I) spectral function
reveals pronounced phonon maxima at 16, 22 and 34meV. For the first time the
high energy maxima at about 50meV and 100meV are resolved. Additionally, an
admixture of a crystalline-electric-field (CEF) excitations with a maximum near
10meV and a `magnetic` peak near 3meV are observed. The contribution of the
10-meV peak in PC EPI constant \lambda_PC is evaluated as 20-30%, while
contribution of the high energy modes at 50 and 100meV amounts about 10% for
each maxima, so the superconductivity might be affected by CEF excitations. The
SC gap in HoNi2B2C exhibits a standard single-band BCS-like dependence, but
vanishes at $T_c^*=5.6K<T_c, with 2\Delta/kT_c^*=3.9. The strong coupling
Eliashberg analysis of the low-temperature SC phase with T_c^*=5.6K =T_N,
coexisting with the commensurate AF structure, suggests a sizable value of the
EPI constant \lambda_s=0.93. We also provide strong support for the recently
proposed by us ''Fermi surface (FS) separation'' scenario for the coexistence
of magnetism and superconductivity in magnetic borocarbides, namely, that the
superconductivity in the commensurate AF phase survives at a special (nearly
isotropic) FS sheet without an admixture of Ho 5d states. Above T_c^* the SC
features in the PC characteristics are strongly suppressed pointing to a
specific weakened SC state between T_c* and T_c.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:54:17 GMT"
}
] | 2007-07-25T00:00:00 | [
[
"Naidyuk",
"Yu. G.",
""
],
[
"Kvitnitskaya",
"O. E.",
""
],
[
"Yanson",
"I. K.",
""
],
[
"Fuchs",
"G.",
""
],
[
"Nenkov",
"K.",
""
],
[
"Waelte",
"A.",
""
],
[
"Behr",
"G.",
""
],
[
"Souptel",
"D.",
""
],
[
"Drechsler",
"S. -L.",
""
]
] |
0705.3406 | Eduard Aschenbach | Bernd Aschenbach | X-ray Evolution of SN 1987A | 10 pages, 9 figures; review talk to appear in the AIP Proceedings of
the Conference " Supernova 1987A: 20 Years after - Supernovae and Gamma-Ray
Bursters" held in Aspen Co USA, Feb 19-23, 2007 | AIP Conf.Proc.937:33-42,2007 | 10.1063/1.2803588 | null | astro-ph | null | The X-ray observations of SN 1987A over the previous 20 years have seen the
emergence of soft X-rays from the interaction of the explosion shock wave with
the ambient medium. This shock wave is now interacting strongly with the inner
ring and might have passed already the highest density regions. The emission
can be described by thermal models with two temperatures, with perhaps some but
little change over time. Relative to the elemental abundances prevailing in the
LMC the inner ring shows an overabundance of Si and S compared to the lighter
elements and Fe, which suggests that the ring consists of highly processed
matter dredged up in a binary merger event well before the explosion. The X-ray
lightcurves between 0.5--2 keV and 3--10 keV differ significantly in slope,
with the latter being much flatter but very similar to the radio light curve.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:55:01 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Aschenbach",
"Bernd",
""
]
] |
0705.3407 | Eduardo Lee | E. J. H. Lee, K. Balasubramanian, J. Dorfmueller, R. Vogelgesang, N.
Fu, A. Mews, M. Burghard, K. Kern | Electronic Band Structure Mapping of Nanotube Transistors by Scanning
Photocurrent Microscopy | 4 pages, 4 figures | null | null | null | cond-mat.mtrl-sci | null | Spatially resolved photocurrent measurements on carbon nanotube field-effect
transistors (CNFETs) operated in various transport regimes are reported. It is
demonstrated that the photocurrents measured at different biasing conditions
provide access to the electronic band structure profile of the nanotube
channel. A comparison of the profiles with the device switched into n- or
p-type states clearly evidences the impact of chemical doping from the ambient.
Moreover, we show that scanning photocurrent microscopy constitutes an
effective and facile technique for the quantitative determination of the
Schottky barrier height in such devices.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 15:57:12 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Lee",
"E. J. H.",
""
],
[
"Balasubramanian",
"K.",
""
],
[
"Dorfmueller",
"J.",
""
],
[
"Vogelgesang",
"R.",
""
],
[
"Fu",
"N.",
""
],
[
"Mews",
"A.",
""
],
[
"Burghard",
"M.",
""
],
[
"Kern",
"K.",
""
]
] |
0705.3408 | John Wallin | John F. Wallin, David S. Dixon, and Gary L. Page | Testing Gravity in the Outer Solar System: Results from Trans-Neptunian
Objects | 20 pages, 4 figures, 2 tables, uses AASTex v5.x macros | Astrophys.J.666:1296-1302,2007 | 10.1086/520528 | null | astro-ph | null | The inverse square law of gravity is poorly probed by experimental tests at
distances of ~ 10 AUs. Recent analysis of the trajectory of the Pioneer 10 and
11 spacecraft have shown an unmodeled acceleration directed toward the Sun
which was not explained by any obvious spacecraft systematics, and occurred
when at distances greater than 20 AUs from the Sun. If this acceleration
represents a departure from Newtonian gravity or is indicative of an additional
mass distribution in the outer solar system, it should be detectable in the
orbits of Trans-Neptunian Objects (TNOs). To place limits on deviations from
Newtonian gravity, we have selected a well observed sample of TNOs found
orbiting between 20 and 100 AU from the Sun. By examining their orbits with
modified orbital fitting software, we place tight limits on the perturbations
of gravity that could exist in this region of the solar system.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:03:08 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Wallin",
"John F.",
""
],
[
"Dixon",
"David S.",
""
],
[
"Page",
"Gary L.",
""
]
] |
0705.3409 | San-Huang Ke | San-Huang Ke, Harold U. Baranger, and Weitao Yang | Electron transport through single conjugated organic molecules: Basis
set effects in ab initio calculations | 6 pages, 7 figures | J. Chem. Phys. 127, 144107 (2007) | 10.1063/1.2770718 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | We investigate electron transport through single conjugated molecules -
including benzenedithiol, oligo-phenylene-ethynylenes of different lengths, and
a ferrocene-containing molecule sandwiched between two gold electrodes with
different contact structures - by using a single-particle Green function method
combined with density functional theory calculation. We focus on the effect of
the basis set in the ab initio calculation. It is shown that the position of
the Fermi energy in the transport gap is sensitive to the molecule-lead charge
transfer which is affected by the size of basis set. This can dramatically
change, by orders of magnitude, the conductance for long molecules, though the
effect is only minor for short ones. A resonance around the Fermi energy tends
to pin the position of the Fermi energy and suppress this effect. The result is
discussed in comparison with experimental data.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:13:46 GMT"
}
] | 2009-08-12T00:00:00 | [
[
"Ke",
"San-Huang",
""
],
[
"Baranger",
"Harold U.",
""
],
[
"Yang",
"Weitao",
""
]
] |
0705.3410 | Daniel Robbins | Matthias Ihl, Daniel Robbins and Timm Wrase | Toroidal Orientifolds in IIA with General NS-NS Fluxes | 59 pages, references added | JHEP 0708:043,2007 | 10.1088/1126-6708/2007/08/043 | UTTG-02-07 | hep-th | null | Type IIA toroidal orientifolds offer a promising toolkit for model builders,
especially when one includes not only the usual fluxes from NS-NS and R-R field
strengths, but also fluxes that are T-dual to the NS-NS three-form flux. These
new ingredients are known as metric fluxes and non-geometric fluxes, and can
help stabilize moduli or can lead to other new features. In this paper we study
two approaches to these constructions, by effective field theory or by toroidal
fibers twisted over a toroidal base. Each approach leads us to important
observations, in particular the presence of D-terms in the four-dimensional
effective potential in some cases, and a more subtle treatment of the
quantization of the general NS-NS fluxes. Though our methods are general, we
illustrate each approach on the example of an orientifold of T^6/Z_4.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:38:38 GMT"
},
{
"version": "v2",
"created": "Wed, 6 Jun 2007 17:12:49 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Ihl",
"Matthias",
""
],
[
"Robbins",
"Daniel",
""
],
[
"Wrase",
"Timm",
""
]
] |
0705.3411 | Bhimsen Shivamoggi | Bhimsen Shivamoggi | Hall Magnetohydrodynamics with Electron Inertia | null | null | null | null | physics.plasm-ph | null | Hall magnetohydrodynamic (MHD) with electron inertia is considered. A much
wider class of equilibrium solutions and the concomitant self-organization
aspects are discussed. The force-free field state B - J is shown to be a
consequence of the triple Beltrami condition.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:17:30 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Sep 2007 16:05:15 GMT"
},
{
"version": "v3",
"created": "Mon, 10 Sep 2007 20:00:28 GMT"
}
] | 2007-09-10T00:00:00 | [
[
"Shivamoggi",
"Bhimsen",
""
]
] |
0705.3412 | Biagio Di Micco | F.Ambrosino, A.Antonelli, M.Antonelli, C.Bacci, P.Beltrame,
G.Bencivenni, S.Bertolucci, C.Bini, C.Bloise, S.Bocchetta, V.Bocci, F.Bossi,
P.Branchini, R.Caloi, P.Campana, G.Capon, T.Capussela, F.Ceradini, S.Chi,
G.Chiefari, P.Ciambrone, E.De Lucia, A.De Santis, P.De Simone, G.De Zorzi,
A.Denig, A.Di Domenico, C.Di Donato, S.Di Falco, B. Di Micco, A.Doria,
M.Dreucci, G.Felici, A.Ferrari, M.L.Ferrer, G.Finocchiaro, S.Fiore, C.Forti,
P.Franzini, C.Gati, P.Gauzzi, S.Giocannella, E.Gorini, E.Graziani, M.Incagli,
W.Kluge, V.Kulikov, F.Lacava, G.Lanfranchi, J.Lee-Franzini, D.Leone,
M.Martini, P.Massartti, W.Mei, S.Meola, S.Miscetti, M.Moulson, S.M\"Uller,
F.Murtas, M.Napolitano, F.Nguyen, M.Palutan, E.Pasqualucci, A.Passeri,
V.Patera, F.Perfetto, M.Primavera, P.Santangelo, G.Saracino, B.Sciascia,
A.Sciubba, F.Scuri, I.Sfiligoi, T.Spadaro, M.Testa, L.Tortora, P.Valente,
B.Valeriani, G.Venanzoni, R.Versaci, G.Xu | eta Physics and phi Radiative Decays at Kloe | Contribution to the proceedings of The 42th Rencontres de Moriond
session devoted to QCD and High Energy Hadronic Interactions | null | null | null | hep-ex | null | Here we present KLOE results on the phi meson decays in pi0 pi0 gamma, pi+
pi- gamma and eta pi0 gamma, the measurement of the ratio Br(phi to eta'
gamma)/Br(phi to eta gamma) with the estimate of the eta' gluonium content and
the measurement of the eta mass.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:22:55 GMT"
},
{
"version": "v2",
"created": "Thu, 24 May 2007 12:54:45 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Ambrosino",
"F.",
""
],
[
"Antonelli",
"A.",
""
],
[
"Antonelli",
"M.",
""
],
[
"Bacci",
"C.",
""
],
[
"Beltrame",
"P.",
""
],
[
"Bencivenni",
"G.",
""
],
[
"Bertolucci",
"S.",
""
],
[
"Bini",
"C.",
""
],
[
"Bloise",
"C.",
""
],
[
"Bocchetta",
"S.",
""
],
[
"Bocci",
"V.",
""
],
[
"Bossi",
"F.",
""
],
[
"Branchini",
"P.",
""
],
[
"Caloi",
"R.",
""
],
[
"Campana",
"P.",
""
],
[
"Capon",
"G.",
""
],
[
"Capussela",
"T.",
""
],
[
"Ceradini",
"F.",
""
],
[
"Chi",
"S.",
""
],
[
"Chiefari",
"G.",
""
],
[
"Ciambrone",
"P.",
""
],
[
"De Lucia",
"E.",
""
],
[
"De Santis",
"A.",
""
],
[
"De Simone",
"P.",
""
],
[
"De Zorzi",
"G.",
""
],
[
"Denig",
"A.",
""
],
[
"Di Domenico",
"A.",
""
],
[
"Di Donato",
"C.",
""
],
[
"Di Falco",
"S.",
""
],
[
"Di Micco",
"B.",
""
],
[
"Doria",
"A.",
""
],
[
"Dreucci",
"M.",
""
],
[
"Felici",
"G.",
""
],
[
"Ferrari",
"A.",
""
],
[
"Ferrer",
"M. L.",
""
],
[
"Finocchiaro",
"G.",
""
],
[
"Fiore",
"S.",
""
],
[
"Forti",
"C.",
""
],
[
"Franzini",
"P.",
""
],
[
"Gati",
"C.",
""
],
[
"Gauzzi",
"P.",
""
],
[
"Giocannella",
"S.",
""
],
[
"Gorini",
"E.",
""
],
[
"Graziani",
"E.",
""
],
[
"Incagli",
"M.",
""
],
[
"Kluge",
"W.",
""
],
[
"Kulikov",
"V.",
""
],
[
"Lacava",
"F.",
""
],
[
"Lanfranchi",
"G.",
""
],
[
"Lee-Franzini",
"J.",
""
],
[
"Leone",
"D.",
""
],
[
"Martini",
"M.",
""
],
[
"Massartti",
"P.",
""
],
[
"Mei",
"W.",
""
],
[
"Meola",
"S.",
""
],
[
"Miscetti",
"S.",
""
],
[
"Moulson",
"M.",
""
],
[
"MÜller",
"S.",
""
],
[
"Murtas",
"F.",
""
],
[
"Napolitano",
"M.",
""
],
[
"Nguyen",
"F.",
""
],
[
"Palutan",
"M.",
""
],
[
"Pasqualucci",
"E.",
""
],
[
"Passeri",
"A.",
""
],
[
"Patera",
"V.",
""
],
[
"Perfetto",
"F.",
""
],
[
"Primavera",
"M.",
""
],
[
"Santangelo",
"P.",
""
],
[
"Saracino",
"G.",
""
],
[
"Sciascia",
"B.",
""
],
[
"Sciubba",
"A.",
""
],
[
"Scuri",
"F.",
""
],
[
"Sfiligoi",
"I.",
""
],
[
"Spadaro",
"T.",
""
],
[
"Testa",
"M.",
""
],
[
"Tortora",
"L.",
""
],
[
"Valente",
"P.",
""
],
[
"Valeriani",
"B.",
""
],
[
"Venanzoni",
"G.",
""
],
[
"Versaci",
"R.",
""
],
[
"Xu",
"G.",
""
]
] |
0705.3413 | St\'ephane Launois | J. Bell, S. Launois and N. Nguyen | Dimension and enumeration of primitive ideals in quantum algebras | 27 pages; introduction rewritten | null | null | null | math.QA math.CO math.RA | null | In this paper, we study the primitive ideals of quantum algebras supporting a
rational torus action. We first prove a quantum analogue of a Theorem of
Dixmier; namely, we show that the Gelfand-Kirillov dimension of primitive
factors of various quantum algebras is always even. Next we give a
combinatorial criterion for a prime ideal that is invariant under the torus
action to be primitive. We use this criterion to obtain a formula for the
number of primitive ideals in the algebra of $2\times n$ quantum matrices that
are invariant under the action of the torus. Roughly speaking, this can be
thought of as giving an enumeration of the points that are invariant under the
induced action of the torus in the ``variety of $2\times n$ quantum matrices''.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:34:13 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 09:46:45 GMT"
}
] | 2007-11-29T00:00:00 | [
[
"Bell",
"J.",
""
],
[
"Launois",
"S.",
""
],
[
"Nguyen",
"N.",
""
]
] |
0705.3414 | J.-P. Macquart | Jean-Pierre Macquart, Ger de Bruyn | Emergence and disappearance of micro-arcsecond structure in the
scintillating quasar J1819+3845 | MNRAS Lett (accepted), version with high-resolution figures at
http://www.astro.caltech.edu/~jpm/MdB1819.pdf | null | 10.1111/j.1745-3933.2007.00341.x | null | astro-ph | null | The 4.8 GHz lightcurves of the scintillating intra-day variable quasar
J1819+3845 during 2004-5 exhibit sharp structure, down to a time scale of 15
minutes, that was absent from lightcurves taken prior to this period and from
the 2006 lightcurves. Analysis of the lightcurve power spectra show that the
variations must be due to the emergence of new structure in the source. The
power spectra yield a scattering screen distance of 3.8 +/- 0.3 pc for a
best-fit v_ISS=59 +/- 0.5 km/s or 2.0 +/- 0.3 pc for the scintillation velocity
reported by Dennett-Thorpe & de Bruyn (2003). The turbulence is required to be
exceptionally turbulent, with C_N^2 > 0.7 Delta L_pc^{-1} m^{-20/3} for
scattering material of thickness Delta L_{pc} pc along the ray path. The 2004
power spectrum can be explained in terms of a double source with a component
separation 240 +/- 15 microas in 2004.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:37:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Macquart",
"Jean-Pierre",
""
],
[
"de Bruyn",
"Ger",
""
]
] |
0705.3415 | Gavriel Segre | Gavriel Segre | Analytic Mechanics of Locally Conservative Physical Systems | null | null | null | null | math-ph math.MP physics.class-ph | null | The analysis of the dynamics of a material point perfectly constrained to a
submanifold of the three-dimensional euclidean space and subjected to a locally
conservative force's field, namely a force's field corresponding to a closed
but not necessarily exact differential form on such a submanifold, requires a
generalization of the Lagrangian and the Hamiltonian formalism that is here
developed.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:59:13 GMT"
},
{
"version": "v2",
"created": "Sun, 27 May 2007 16:45:57 GMT"
}
] | 2007-05-29T00:00:00 | [
[
"Segre",
"Gavriel",
""
]
] |
0705.3416 | Jose Castro | P. Gupta, S. Laha, C. E. Simien, H. Gao, J. Castro, T. Pohl and T. C.
Killian | Electron Temperature Evolution in Expanding Ultracold Neutral Plasmas | null | null | 10.1103/PhysRevLett.99.075005 | null | physics.atom-ph physics.plasm-ph | null | We have used the free expansion of ultracold neutral plasmas as a
time-resolved probe of electron temperature. A combination of experimental
measurements of the ion expansion velocity and numerical simulations
characterize the crossover from an elastic-collision regime at low initial
Gamma_e, which is dominated by adiabatic cooling of the electrons, to the
regime of high Gamma_e in which inelastic processes drastically heat the
electrons. We identify the time scales and relative contributions of various
processes, and experimentally show the importance of radiative decay and
disorder-induced electron heating for the first time in ultracold neutral
plasmas.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:44:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gupta",
"P.",
""
],
[
"Laha",
"S.",
""
],
[
"Simien",
"C. E.",
""
],
[
"Gao",
"H.",
""
],
[
"Castro",
"J.",
""
],
[
"Pohl",
"T.",
""
],
[
"Killian",
"T. C.",
""
]
] |
0705.3417 | Graciela Domenech | Graciela Domenech and Federico Holik | A discussion on particle number and quantum indistinguishability | 46 pages, no figures. Accepted by Foundations of Physics | Foundations of Physics 37 (2007) 855-878 | 10.1007/s10701-007-9129-5 | null | quant-ph | null | The concept of individuality in quantum mechanics shows radical differences
from the concept of individuality in classical physics, as E. Schroedinger
pointed out in the early steps of the theory. Regarding this fact, some authors
suggested that quantum mechanics does not possess its own language, and
therefore, quantum indistinguishability is not incorporated in the theory from
the beginning. Nevertheless, it is possible to represent the idea of quantum
indistinguishability with a first order language using quasiset theory (Q). In
this work, we show that Q cannot capture one of the most important features of
quantum non individuality, which is the fact that there are quantum systems for
which particle number is not well defined. An axiomatic variant of Q, in which
quasicardinal is not a primitive concept (for a kind of quasisets called finite
quasisets), is also given. This result encourages the searching of theories in
which the quasicardinal, being a secondary concept, stands undefined for some
quasisets, besides showing explicitly that in a set theory about collections of
truly indistinguishable entities, the quasicardinal needs not necessarily be a
primitive concept.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:46:36 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Domenech",
"Graciela",
""
],
[
"Holik",
"Federico",
""
]
] |
0705.3418 | Emanuela Zaccarelli | Emanuela Zaccarelli | Colloidal Gels: Equilibrium and Non-Equilibrium Routes | topical review, accepted in J. Phys. Condens. Matter | J. Phys.: Condens. Matter 19, 323101 (2007) | 10.1088/0953-8984/19/32/323101 | null | cond-mat.soft | null | We attempt a classification of different colloidal gels based on
colloid-colloid interactions. We discriminate primarily between non-equilibrium
and equilibrium routes to gelation, the former case being slaved to
thermodynamic phase separation while the latter is individuated in the
framework of competing interactions and of patchy colloids. Emphasis is put on
recent numerical simulations of colloidal gelation and their connection to
experiments. Finally we underline typical signatures of different gel types, to
be looked in more details in experiments.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:48:24 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Jun 2007 20:57:55 GMT"
}
] | 2007-08-07T00:00:00 | [
[
"Zaccarelli",
"Emanuela",
""
]
] |
0705.3419 | Balazs Szendroi | Balazs Szendroi | Non-commutative Donaldson-Thomas theory and the conifold | Infinite product form, conjectured in v1, now a theorem of Ben Young.
Additional discussion of small-volume expansion related to Eisenstein-like
series | Geom.Topol.12:1171-1202,2008 | 10.2140/gt.2008.12.1171 | null | math.AG hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Given a quiver algebra A with relations defined by a superpotential, this
paper defines a set of invariants of A counting framed cyclic A-modules,
analogous to rank-1 Donaldson-Thomas invariants of Calabi-Yau threefolds. For
the special case when A is the non-commutative crepant resolution of the
threefold ordinary double point, it is proved using torus localization that the
invariants count certain pyramid-shaped partition-like configurations, or
equivalently infinite dimer configurations in the square dimer model with a
fixed boundary condition. The resulting partition function admits an infinite
product expansion, which factorizes into the rank-1 Donaldson-Thomas partition
functions of the commutative crepant resolution of the singularity and its
flop. The different partition functions are speculatively interpreted as
counting stable objects in the derived category of A-modules under different
stability conditions; their relationship should then be an instance of wall
crossing in the space of stability conditions on this triangulated category.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:59:48 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Jul 2007 09:17:55 GMT"
},
{
"version": "v3",
"created": "Fri, 19 Sep 2008 19:10:31 GMT"
}
] | 2008-11-07T00:00:00 | [
[
"Szendroi",
"Balazs",
""
]
] |
0705.3420 | Alessandra Feo | R. De Pietri, A. Feo, E. Seiler and I.-O. Stamatescu | A Model for QCD at High Density and Large Quark Mass | 21 pages, 29 figures | Phys.Rev.D76:114501,2007 | 10.1103/PhysRevD.76.114501 | null | hep-lat hep-ph hep-th nucl-th | null | We study the high density region of QCD within an effective model obtained in
the frame of the hopping parameter expansion and choosing Polyakov type of
loops as the main dynamical variables representing the fermionic matter. To get
a first idea of the phase structure, the model is analyzed in strong coupling
expansion and using a mean field approximation. In numerical simulations, the
model still shows the so-called sign problem, a difficulty peculiar to non-zero
chemical potential, but it permits the development of algorithms which ensure a
good overlap of the Monte Carlo ensemble with the true one. We review the main
features of the model and present calculations concerning the dependence of
various observables on the chemical potential and on the temperature, in
particular of the charge density and the diquark susceptibility, which may be
used to characterize the various phases expected at high baryonic density. We
obtain in this way information about the phase structure of the model and the
corresponding phase transitions and cross over regions, which can be considered
as hints for the behaviour of non-zero density QCD.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:13:05 GMT"
},
{
"version": "v2",
"created": "Sun, 9 Sep 2007 11:28:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"De Pietri",
"R.",
""
],
[
"Feo",
"A.",
""
],
[
"Seiler",
"E.",
""
],
[
"Stamatescu",
"I. -O.",
""
]
] |
0705.3421 | Willy Kley | Willy Kley (1) and Richard Nelson (2) ((1) University of Tuebingen,
(2) QMUL) | On the Formation and Dynamical Evolution of Planets in Binaries | Chapter to appear in the book "Planets in Binary Star Systems," ed.
Nader Haghighipour (Springer publishing company), 2007 | null | null | null | astro-ph | null | Among the extrasolar planetary systems about 30 are located in a stellar
binary orbiting one of the stars, preferably the more massive primary. The
dynamical influence of the second companion alters firstly the orbital elements
of the forming protoplanet directly and secondly the structure of the disk from
which the planet formed which in turn will modify the planet's evolution. We
present detailed analysis of these effects and present new hydrodynamical
simulations of the evolution of protoplanets embedded in circumstellar disks in
the presence of a companion star, and compare our results to the system
$\gamma$ Cep. To analyse the early formation of planetary embryos, we follow
the evolution of a swarm of planetesimals embedded in a circumstellar disk.
Finally, we study the evolution of planets embedded in circumbinary disks.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 16:56:20 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Kley",
"Willy",
""
],
[
"Nelson",
"Richard",
""
]
] |
0705.3422 | Friedrich W. Hehl | Friedrich W. Hehl (Cologne and Missouri-Columbia) and Yu.N. Obukhov
(Cologne and Moscow) | Equivalence principle and electromagnetic field: no birefringence, no
dilaton, and no axion | 13 pages latex | Gen.Rel.Grav.40:1239-1248,2008 | 10.1007/s10714-007-0601-5 | null | gr-qc hep-th physics.class-ph | null | The coupling of the electromagnetic field to gravity is discussed. In the
premetric axiomatic approach based on the experimentally well established
conservation laws of electric charge and magnetic flux, the Maxwell equations
are the same irrespective of the presence or absence of gravity. In this sense,
one can say that the charge "substratum" and the flux "substratum" are not
influenced by the gravitational field directly. However, the interrelation
between these fundamental substrata, formalized as the {\it spacetime relation}
H=H(F) between the 2-forms of the electromagnetic excitation H and the
electromagnetic field strength F, is affected by gravity. Thus the validity of
the equivalence principle for electromagnetism depends on the form of the
spacetime relation. We discuss the nonlocal and local linear constitutive
relations and demonstrate that the spacetime metric can be accompanied also by
skewon, dilaton, and axion fields. All these premetric companions of the metric
may eventually lead to a violation of the equivalence principle.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:00:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hehl",
"Friedrich W.",
"",
"Cologne and Missouri-Columbia"
],
[
"Obukhov",
"Yu. N.",
"",
"Cologne and Moscow"
]
] |
0705.3423 | Jordan Bell | Leonhard Euler | Annotations to a certain passage of Descartes for finding the quadrature
of the circle | 14 pages, 4 figures | null | null | null | math.HO math.CA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Translation from the Latin of "Annotationes in locum quendam Cartesii ad
circuli quadraturam spectantem" (1763).
The passage Euler is referring to is the "Excerpta" in part 6, p. 6 of
Descartes' 1701 "Opuscula posthuma".
Before reading this paper I had not heard of the "quadratrix" before, and I
recommend learning a bit about it before reading this. I found Thomas Heath, "A
history of Greek mathematics", vol. I, chapter VII to be helpful, in particular
pp. 226-230. The quadratrix is a "mechanical curve" that can be used to rectify
the circle. The usual problem of squaring the circle is to construct a square
with the same area (or perimeter) as a given circle, in a finite number of
steps using compass and straightedge. Descartes worked in the reverse
direction: from a given square he constructed the radius of a circle with the
same perimeter, but in an infinite number of steps.
In this paper Euler reconstructs Descartes' argument and develops some
consequences of it. Euler finds that \[ \sum_{n=0}^\infty \frac{1}{2^n} \tan
\frac{1}{2^n}\phi = \frac{1}{\phi} - 2\cot 2\phi. \] Integrating this yields \[
\prod_{n=1}^\infty \sec \frac{1}{2^n} \phi = \frac{2\phi}{\sin 2\phi}. \]
I'd like to thank Davide Crippa from the University of Paris 7 for some
helpful back and forth about this paper.
One of the only citations to this paper that I have found is in Pietro
Ferroni, De calculo integralium exercitatio mathematica, Allegrini, Florence,
1792, pp. xxi--xxiii. The full text of it is available on Google Books.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:00:13 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Apr 2009 03:25:46 GMT"
}
] | 2009-04-16T00:00:00 | [
[
"Euler",
"Leonhard",
""
]
] |
0705.3424 | David Kerr | David Kerr, Hanfeng Li | Combinatorial independence in measurable dynamics | 44 pages | null | null | null | math.DS math.FA | null | We develop a fine-scale local analysis of measure entropy and measure
sequence entropy based on combinatorial independence. The concepts of measure
IE-tuples and measure IN-tuples are introduced and studied in analogy with
their counterparts in topological dynamics. Local characterizations of the
Pinsker von Neumann algebra and its sequence entropy analogue are given in
terms of combinatorial independence, l_1 geometry, and Voiculescu's completely
positive approximation entropy. Among the novel features of our local study is
the treatment of general discrete acting groups, with the structural assumption
of amenability in the case of entropy.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:03:32 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Kerr",
"David",
""
],
[
"Li",
"Hanfeng",
""
]
] |
0705.3425 | Antongiulio Fornasiero | Alessandro Berarducci, Antongiulio Fornasiero | O-minimal cohomology: finiteness and invariance results | 28 pages, 7 figures and diagrams Added the hypothesis that singletons
are construcible to section 3. Corrected misprints | Journal of Mathematical Logic (JML), Volume 9, Issue 2(2009), pp.
167-182 | 10.1142/S0219061309000859 | null | math.LO math.AT | null | We prove that the cohomology groups of a definably compact set over an
o-minimal expansion of a group are finitely generated and invariant under
elementary extensions and expansions of the language. We also study the
cohomology of the intersection of a definable decreas-ing family of definably
compact sets, under the additional assumption that the o-minimal structure
expands a field.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:07:45 GMT"
},
{
"version": "v2",
"created": "Sun, 27 May 2007 19:40:11 GMT"
}
] | 2010-09-28T00:00:00 | [
[
"Berarducci",
"Alessandro",
""
],
[
"Fornasiero",
"Antongiulio",
""
]
] |
0705.3426 | David Kaplan | David E. Kaplan and Keith Rehermann | Proposal for Higgs and Superpartner Searches at the LHCb Experiment | 7 pages, 5 figures | JHEP 0710:056,2007 | 10.1088/1126-6708/2007/10/056 | null | hep-ph hep-ex | null | The spectrum of supersymmetric theories with R-parity violation are much more
weakly constrained than that of supersymmetric theories with a stable
neutralino. We investigate the signatures of supersymmetry at the LHCb
experiment in the region of parameter space where the neutralino decay leaves a
displaced vertex. We find sensitivity to squark production up to squark masses
of order 1 TeV. We note that if the Higgs decays to neutralinos in this
scenario, LHCb should see the lightest Higgs boson before ATLAS and CMS.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:20:48 GMT"
},
{
"version": "v2",
"created": "Wed, 23 May 2007 22:39:52 GMT"
}
] | 2009-04-22T00:00:00 | [
[
"Kaplan",
"David E.",
""
],
[
"Rehermann",
"Keith",
""
]
] |
0705.3427 | Nicola Romanazzi | Robert Gilmore (1,2), Christophe Letellier (2), Nicola Romanazzi (1)
((1)Physics Department, Drexel University, Philadelphia, PA,(2) CORIA UMR
6614 - Universite de Rouen, France) | Global Topology from an Embedding | null | null | 10.1088/1751-8113/40/44/010 | null | nlin.CD | null | An embedding of chaotic data into a suitable phase space creates a
diffeomorphism of the original attractor with the reconstructed attractor.
Although diffeomorphic, the original and reconstructed attractors may not be
topologically equivalent. In a previous work we showed how the original and
reconstructed attractors can differ when the original is three-dimensional and
of genus-one type. In the present work we extend this result to
three-dimensional attractors of arbitrary genus. This result describes
symmetries exhibited by the Lorenz attractor and its reconstructions.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:24:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gilmore",
"Robert",
""
],
[
"Letellier",
"Christophe",
""
],
[
"Romanazzi",
"Nicola",
""
]
] |
0705.3428 | Sergey Pankov | S. Pankov, V. Dobrosavljevic | Self-doping instability of the Wigner-Mott insulator | 5 pages, 2 figures | Phys. Rev. B 77, 085104 (2008) | 10.1103/PhysRevB.77.085104 | null | cond-mat.str-el | null | We present a theory describing the mechanism for the two-dimensional (2D)
metal-insulator transition (MIT) in absence of disorder. A two-band Hubbard
model is introduced, describing vacancy-interstitial pair excitations within
the Wigner crystal. Kinetic energy gained by delocalizing such excitations is
found to lead to an instability of the insulator to self-doping above a
critical carrier concentration $n=n_c$, mapping the problem to a density-driven
Mott MIT. This mechanism provides a natural microscopic picture of several
puzzling experimental features, including the large effective mass enhancement,
the large resistivity drop, and the large positive magneto-resistance on the
metallic side of the transition. We also present a global phase diagram for the
clean 2D electron gas as a function of $n$ and parallel magnetic field
$B_{\shortparallel}$, which agrees well with experimental findings in ultra
clean samples.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:28:06 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Feb 2008 18:41:54 GMT"
}
] | 2008-02-15T00:00:00 | [
[
"Pankov",
"S.",
""
],
[
"Dobrosavljevic",
"V.",
""
]
] |
0705.3429 | Roby Cherian | Roby Cherian and Priya Mahadevan | Elastic Properties of Carbon nanotubes : An atomistic approach | 10 pages, 4 figures | Journal of Nanoscience and Nanotechnology, Volume 7, Number 6,
June 2007, pp. 1779-1782(4) | null | null | cond-mat.mtrl-sci | null | Energetically the single sheet of graphite (graphene) is more stable than the
nanotube. The energy difference between the two systems can be directly related
to the strain energy involved in rolling up the graphene sheet to form the
nanotube. We have carried out first principle electronic structure calculations
and evaluated the strain energy as a function of the nanotube radius. The
dependence of the strain energy on the diameter of the nanotube has been found
by several groups to be welldescribed by a continuum elasticity model. We
attempt to examine why this is the case and show where atomistics enter the
description.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:28:16 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Cherian",
"Roby",
""
],
[
"Mahadevan",
"Priya",
""
]
] |
0705.3430 | John Angle | John Angle | The Macro Model of the Inequality Process and The Surging Relative
Frequency of Large Wage Incomes | 26 pages, 21 eps figures, Springer style; to be published in
Econophysics of Markets and Business Networks, [Proc. Econophys-Kolkata III],
Eds. A. Chatterjee, B.K. Chakrabarti, New Economic Windows Series, Springer,
Milan, 2007, pp. 171-196 | null | 10.1007/978-88-470-0665-2_14 | null | q-fin.GN physics.data-an physics.soc-ph | null | This paper presents a model of the dynamics of the wage income distribution.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:31:07 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Angle",
"John",
""
]
] |
0705.3431 | Emily Levesque | Emily M. Levesque, Philip Massey, K. A. G. Olsen, Bertrand Plez | Late-Type Red Supergiants: Too Cool for the Magellanic Clouds? | 26 pages, 6 figures; submitted to the Astrophysical Journal | Astrophys.J.667:202-212,2007 | 10.1086/520797 | null | astro-ph | null | We have identified seven red supergiants (RSGs) in the Large Magellanic Cloud
(LMC) and four RSGs in the Small Magellanic Cloud (SMC), all of which have
spectral types that are considerably later than the average type observed in
their parent galaxy. Using moderate-resolution optical spectrophotometry and
the MARCS stellar atmosphere models, we determine their physical properties and
place them on the H-R diagram for comparison with the predictions of current
stellar evolutionary tracks. The radial velocities of these stars suggest that
they are likely all members of the Clouds rather than foreground dwarfs or halo
giants. Their locations in the H-R diagram also show us that those stars are
cooler than the current evolutionary tracks allow, appearing to the right of
the Hayashi limit, a region in which stars are no longer in hydrodynamic
equilibrium. These stars exhibit considerable variability in their V
magnitudes, and three of these stars also show changes in their effective
temperatures (and spectral types) on the time-scales of months. One of these
stars, [M2002] SMC 055188, was caught in an M4.5 I state, as late as that seen
in HV 11423 at its recent extreme: considerable later, and cooler, than any
other supergiant in the SMC. In addition, we find evidence of variable
extinction due to circumstellar dust and changes in the stars' luminosities,
also consistent with our recent findings for HV 11423 - when these stars are
hotter they are also dustier and more luminous. We suggest that these stars
have unusual properties because they are in an unstable (and short-lived)
evolutionary phase.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:31:54 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Levesque",
"Emily M.",
""
],
[
"Massey",
"Philip",
""
],
[
"Olsen",
"K. A. G.",
""
],
[
"Plez",
"Bertrand",
""
]
] |
0705.3432 | Volker Runde | Matthew Daws, Volker Runde | Reiter's properties (P_1) and (P_2) for locally compact quantum groups | 23 pages; some rewriting, references added | J. Math. Anal. Appl. 364 (2010), 352-365 | null | null | math.OA math.FA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A locally compact group $G$ is amenable if and only if it has Reiter's
property $(P_p)$ for $p=1$ or, equivalently, all $p \in [1,\infty)$, i.e.,
there is a net $(m_\alpha)_\alpha$ of non-negative norm one functions in
$L^p(G)$ such that $\lim_\alpha \sup_{x \in K} \| L_{x^{-1}} m_\alpha -
m_\alpha \|_p = 0$ for each compact subset $K \subset G$ ($L_{x^{-1}} m_\alpha$
stands for the left translate of $m_\alpha$ by $x^{-1}$). We extend the
definitions of properties $(P_1)$ and $(P_2)$ from locally compact groups to
locally compact quantum groups in the sense of J. Kustermans and S. Vaes. We
show that a locally compact quantum group has $(P_1)$ if and only if it is
amenable and that it has $(P_2)$ if and only if its dual quantum group is
co-amenable. As a consequence, $(P_2)$ implies $(P_1)$.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:32:30 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Nov 2007 20:48:39 GMT"
},
{
"version": "v3",
"created": "Thu, 14 Feb 2008 16:49:21 GMT"
},
{
"version": "v4",
"created": "Fri, 8 Aug 2008 01:18:56 GMT"
},
{
"version": "v5",
"created": "Fri, 13 Nov 2009 17:13:21 GMT"
}
] | 2010-02-24T00:00:00 | [
[
"Daws",
"Matthew",
""
],
[
"Runde",
"Volker",
""
]
] |
0705.3433 | Volker Runde | Volker Runde | Why prove things? | 6 pages, 4 figures; intended for high school students | Pi in the Sky 11 (2008), 12-15 | null | null | math.HO | null | We illustrate the concept of mathematical proof.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:41:41 GMT"
}
] | 2008-03-17T00:00:00 | [
[
"Runde",
"Volker",
""
]
] |
0705.3434 | Roby Cherian | Roby Cherian, Priya Mahadevan | Bulk and nano GaN: Role of Ga d states | 17 pages, 7 figures | null | 10.1103/PhysRevB.76.075205 | null | cond-mat.mtrl-sci | null | We have studied the role of Ga 3d states in determining the properties of
bulk as well as nanoparticles of GaN using PAW potentials. A significant
contribution of the Ga d states in the valence band is found to arise from the
interaction of Ga 4d states with the dominantly N p states making up the
valence band. The errors arising from not treating the Ga 3d states as a part
of the valence are found to be similar, ~ 1%, for bulk as well as for
nanoclusters of GaN.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:32:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cherian",
"Roby",
""
],
[
"Mahadevan",
"Priya",
""
]
] |
0705.3435 | Martin Schaden | Martin Schaden and Liviu Mateescu | Weak and Repulsive Casimir Force in Piston Geometries | 8 pages, 2 figures, enhanced talk presented at APS March Meeting 2007 | null | null | null | quant-ph cond-mat.mes-hall | null | We study the Casimir force in piston-like geometries semiclassically. The
force on the piston is finite and physical, but to leading semiclassical
approximation depends strongly on the shape of the surrounding cavity. Whereas
this force is attractive for pistons in a parallelepiped with flat cylinder
head, for which the semiclassical approximation by periodic orbits is exact,
this approximation to the force on the piston vanishes for a semi-cylindrical
head and becomes repulsive for a cylinder of circular cross section with a
hemispherical head. In leading semiclassical approximation the sign of the
force is related to the generalized Maslov index of short periodic orbits
between the piston and its casing.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:54:08 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Schaden",
"Martin",
""
],
[
"Mateescu",
"Liviu",
""
]
] |
0705.3436 | Richard Edgar | Richard G. Edgar, Alice C. Quillen, Jaehong Park | The Minimum Gap-opening Planet Mass in an Irradiated Circumstellar
Accretion Disk | Eight pages, submitted to MNRAS Resubmitting accepted version of the
paper | null | 10.1111/j.1365-2966.2007.12305.x | null | astro-ph | null | We consider the minimum mass planet, as a function of radius, that is capable
of opening a gap in an $\alpha$-accretion disk. We estimate that a half Jupiter
mass planet can open a gap in a disk with accretion rate $\dot M \la 10^{-8}
M_\odot$/yr for viscosity parameter $\alpha =0.01$, and Solar mass and
luminosity. The minimum mass is approximately proportional to $\dot M^{0.48}
\alpha^{0.8} M_*^{0.42} L_*^{-0.08}$. This estimate can be used to rule out the
presence of massive planets in gapless accretion disks. We identify two radii
at which an inwardly migrating planet may become able to open a gap and so slow
its migration; the radius at which the heating from viscous dissipation is
similar to that from stellar radiation in a flared disk, and the radius at
which the disk has optical depth order 1 in a self-shadowed disk. If a gap
opening planet cuts off disk accretion allowing the formation of a central hole
or clearing in the disk then we would estimate that the clearing radius would
approximately be proportional to the stellar mass.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:56:09 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 13:36:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Edgar",
"Richard G.",
""
],
[
"Quillen",
"Alice C.",
""
],
[
"Park",
"Jaehong",
""
]
] |
0705.3437 | Vincent Rivasseau | R. Gurau, A.P.C. Malbouisson, V. Rivasseau and A. Tanasa | Non-Commutative Complete Mellin Representation for Feynman Amplitudes | 14 pages, no figure | Lett.Math.Phys.81:161-175,2007 | 10.1007/s11005-007-0170-2 | null | math-ph hep-th math.MP | null | We extend the complete Mellin (CM) representation of Feynman amplitudes to
the non-commutative quantum field theories. This representation is a versatile
tool. It provides a quick proof of meromorphy of Feynman amplitudes in
parameters such as the dimension of space-time. In particular it paves the road
for the dimensional renormalization of these theories. This complete Mellin
representation also allows the study of asymptotic behavior under rescaling of
arbitrary subsets of external invariants of any Feynman amplitude.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:56:38 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gurau",
"R.",
""
],
[
"Malbouisson",
"A. P. C.",
""
],
[
"Rivasseau",
"V.",
""
],
[
"Tanasa",
"A.",
""
]
] |
0705.3438 | Terrence Girard | D. I. Casetti-Dinescu, T. M. Girard, D. Herrera, W. F. van Altena, C.
E. L\'opez and D. J. Castillo | Space Velocities of Southern Globular Clusters. V. A Low Galactic
Latitude Sample | To appear in AJ 134, 195 | Astron.J.134:195-204,2007 | 10.1086/518507 | null | astro-ph | null | We have measured the absolute proper motions of globular clusters NGC 2808,
3201, 4372, 4833, 5927 and 5986. The proper motions are on the Hipparcos system
and they are the first determinations ever made for these low Galactic latitude
clusters. The proper motion uncertainties range from 0.3 to 0.5 mas/yr. The
inferred orbits indicate that 1) the single metal rich cluster in our sample,
NGC 5927, dynamically belongs to the thick disk, 2) the remaining metal poor
clusters have rather low-energy orbits of high eccentricity; among these, there
appear to be two "pairs" of dynamically associated clusters, 3) the most
energetic cluster in our sample, NGC 3201 is on a highly retrograde orbit --
which had already been surmised from its radial velocity alone -- with an
apocentric distance of 22 kpc, and 4) none of the metal poor clusters appear to
be associated with the recently detected SDSS streams, or with the Monoceros
structure.
These are the first results of the Southern Proper-Motion Program (SPM) where
the second-epoch observations are taken with the CCD camera system recently
installed on the double astrograph at El Leoncito, Argentina.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:58:43 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Casetti-Dinescu",
"D. I.",
""
],
[
"Girard",
"T. M.",
""
],
[
"Herrera",
"D.",
""
],
[
"van Altena",
"W. F.",
""
],
[
"López",
"C. E.",
""
],
[
"Castillo",
"D. J.",
""
]
] |
0705.3439 | Magdalena Djordjevic | Magdalena Djordjevic, Ulrich Heinz | Radiative heavy quark energy loss in a dynamical QCD medium | 21 pages, 14 figures, submitted to Physical Review C | Phys.Rev.C77:024905,2008 | 10.1103/PhysRevC.77.024905 | null | nucl-th | null | The computation of radiative energy loss in a dynamically screened QCD medium
is a key ingredient for obtaining reliable predictions for jet quenching in
ultra-relativistic heavy ion collisions. We calculate, to first order in the
opacity, the energy loss suffered by a heavy quark traveling through an
infinite and time-independent QCD medium and show that the result for a
dynamical medium is almost twice that obtained previously for a medium
consisting of randomly distributed static scattering centers. A quantitative
description of jet suppression in RHIC and LHC experiments thus must correctly
account for the dynamics of the medium's constituents.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 17:41:50 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Djordjevic",
"Magdalena",
""
],
[
"Heinz",
"Ulrich",
""
]
] |
0705.3440 | Klaus Bering | K. Bering | Semidensities, Second-Class Constraints and Conversion in Anti-Poisson
Geometry | 32 pages, LaTeX. v2: Minor changes. v3: Published version | J.Math.Phys.49:043516,2008 | 10.1063/1.2890672 | null | hep-th math-ph math.MP math.SG | null | We consider Khudaverdian's geometric version of a Batalin-Vilkovisky (BV)
operator \Delta_E in the case of a degenerate anti-Poisson manifold. The
characteristic feature of such an operator (aside from being a Grassmann-odd,
nilpotent, second-order differential operator) is that it sends semidensities
to semidensities. We find a local formula for the \Delta_E operator in
arbitrary coordinates. As an important application of this setup, we consider
the Dirac antibracket on an antisymplectic manifold with antisymplectic
second-class constraints. We show that the entire Dirac construction, including
the corresponding Dirac BV operator \Delta_{E_D}, exactly follows from
conversion of the antisymplectic second-class constraints into first-class
constraints on an extended manifold.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:09:57 GMT"
},
{
"version": "v2",
"created": "Sun, 30 Sep 2007 09:48:48 GMT"
},
{
"version": "v3",
"created": "Fri, 25 Apr 2008 19:12:48 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bering",
"K.",
""
]
] |
0705.3441 | Vallery Stanishev | V. Stanishev | Correcting second-order contamination in low-resolution spectra | accepted for publication in Astronomical Notes (Astronomische
Nachrichten) | null | 10.1002/asna.200710779 | null | astro-ph | null | An empirical method for correcting low-resolution astronomical spectra for
second-order contamination is presented. The method was developed for
correcting spectra obtained with grism #4 of the ALFOSC spectrograph at the
Nordic Optical Telescope and the performance is demonstrated on spectra of two
nearby bright Type Ia supernovae.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:11:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stanishev",
"V.",
""
]
] |
0705.3442 | Brian Sawyer | Brian C. Sawyer, Benjamin K. Stuhl, Benjamin L. Lev, Eric R. Hudson,
and Jun Ye | Mitigation of loss within a molecular Stark decelerator | 13 pages, 17 figures | Eur. Phys. J. D 48, 197 (2008) | 10.1140/epjd/e2008-00097-y | null | physics.atom-ph physics.atm-clus | null | The transverse motion inside a Stark decelerator plays a large role in the
total efficiency of deceleration. We differentiate between two separate regimes
of molecule loss during the slowing process. The first mechanism involves
distributed loss due to coupling of transverse and longitudinal motion, while
the second is a result of the rapid decrease of the molecular velocity within
the final few stages. In this work, we describe these effects and present means
for overcoming them. Solutions based on modified switching time sequences with
the existing decelerator geometry lead to a large gain of stable molecules in
the intermediate velocity regime, but fail to address the loss at very low
final velocities. We propose a new decelerator design, the quadrupole-guiding
decelerator, which eliminates distributed loss due to transverse/longitudinal
couplings throughout the slowing process and also exhibits gain over normal
deceleration to the lowest velocities.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:49:18 GMT"
}
] | 2008-06-23T00:00:00 | [
[
"Sawyer",
"Brian C.",
""
],
[
"Stuhl",
"Benjamin K.",
""
],
[
"Lev",
"Benjamin L.",
""
],
[
"Hudson",
"Eric R.",
""
],
[
"Ye",
"Jun",
""
]
] |
0705.3443 | Borys Alvarez-Samaniego | Borys Alvarez-Samaniego | Comment on "Orbital stability of solitary wave solutions for an
interaction equation of short and long dispersive waves" | 2 pages | null | null | null | math.AP math-ph math.MP | null | J. Angulo and J. F. Montenegro (J. Differential Equations 174 (2001), no. 1,
181-199) published a paper about nonlinear stability of solitary waves for an
interaction system between a long internal wave and a short surface wave in a
two layer fluid considering that the fluid depth of the lower layer is
sufficiently large in comparison with the wavelength of the internal wave. In
this note, we show that in a critical step during the proof of Lemma 2.4 in the
above mentioned paper, there is a claim used by the authors which fails to be
true. Lemma 2.4 is crucial for the proof of Lemma 2.7, and for the proof of
stability in Theorem 2.1 in the paper before mentioned.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:22:18 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Alvarez-Samaniego",
"Borys",
""
]
] |
0705.3444 | Elisa Quintana | Elisa V. Quintana and Jack J. Lissauer | Terrestrial Planet Formation in Binary Star Systems | Chapter to appear in the book "Planets in Binary Star Systems," ed.
Nader Haghighipour (Springer publishing company), 2007 | null | null | null | astro-ph | null | A binary star system is the most common result of the star formation process,
and binary companions can disrupt both the formation of terrestrial planets and
their long term prospects for stability. We present results from a large set of
numerical simulations of the final stages of terrestrial planet formation -
from Moon- to Mars-sized planetary embryos to planets - in main-sequence binary
star systems. We examine planetary accretion around both stars ('P-type'
circumbinary orbits) or individual stars ('S-type' orbits) in binary systems,
including terrestrial planet formation around each star in Alpha Centauri AB,
the closest binary star system to the Sun. For comparison, we also simulate
planetary growth from the same initial disk placed in the Sun-Jupiter-Saturn
system and also around the Sun with neither giant planets nor a stellar
companion perturbing the system. Our simulations show that giant and stellar
companions not only truncate the disk, but hasten the accretion process by
stirring up the planetary embryos to higher eccentricities and inclinations.
Terrestrial planets similar to those in our Solar System formed around
individual stars in simulations with the binary periastron (closest approach)
greater than about 5 AU. Terrestrial planet growth within circumbinary disks
was uninhibited around inner binary star systems with binary apastrons (maximum
separation) less than ~0.2 AU. Results from our simulations can be scaled for
different stellar and disk parameters. Approximately 50 - 60% of binary star
systems - from contact binaries to separations of nearly a parsec - satisfy
these constraints. Given that the galaxy contains more than 100 billion star
systems, a large number of systems remain habitable based on the dynamic
considerations of this research.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:37:14 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Quintana",
"Elisa V.",
""
],
[
"Lissauer",
"Jack J.",
""
]
] |
0705.3445 | Michael Kinyon | Michael K. Kinyon, Kyle Pula, and Petr Vojtechovsky | Admissible orders of Jordan loops | 15 pages. V2: final version with small changes suggested by referee,
to appear in J. Combinatorial Design | J. Combinatorial Designs 17 (2009), no. 2, 103-118 | null | null | math.GR | null | A commutative loop is Jordan if it satisfies the identity $x^2 (y x) = (x^2
y) x$. Using an amalgam construction and its generalizations, we prove that a
nonassociative Jordan loop of order $n$ exists if and only if $n\geq 6$ and
$n\neq 9$. We also consider whether powers of elements in Jordan loops are
well-defined, and we construct an infinite family of finite simple
nonassociative Jordan loops.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:51:57 GMT"
},
{
"version": "v2",
"created": "Thu, 24 Jan 2008 14:52:19 GMT"
}
] | 2011-08-19T00:00:00 | [
[
"Kinyon",
"Michael K.",
""
],
[
"Pula",
"Kyle",
""
],
[
"Vojtechovsky",
"Petr",
""
]
] |
0705.3446 | James S. Milne | J.S. Milne | The fundamental theorem of complex multiplication | 33 pages | null | null | null | math.NT math.AG | null | The goal of this expository article is to present a proof that is as direct
and elementary as possible of the fundamental theorem of complex multiplication
(Shimura, Taniyama, Langlands, Tate, Deligne et al.).
The article is a revision of part of my manuscript, Complex Multiplication,
April 7, 2006.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:35:34 GMT"
}
] | 2007-05-24T00:00:00 | [
[
"Milne",
"J. S.",
""
]
] |
0705.3447 | Alvaro de Souza Dutra | Alvaro de Souza Dutra and M. B. Hott (UNESP/Campus de
Guaratingueta-DFQ) | Dirac equation exact solutions for generalized asymmetrical Hartmann
potentials | 8 pages, no figures | null | 10.1016/j.physleta.2006.03.042 | null | quant-ph hep-th | null | In this work we solve the Dirac equation by constructing the exact bound
state solutions for a mixing of vector and scalar generalized Hartmann
potentials. This is done provided the vector potential is equal to or minus the
scalar potential. The cases of some quasi-exactly solvable and Morse-like
potentials are briefly commented.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 18:53:52 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Dutra",
"Alvaro de Souza",
"",
"UNESP/Campus de\n Guaratingueta-DFQ"
],
[
"Hott",
"M. B.",
"",
"UNESP/Campus de\n Guaratingueta-DFQ"
]
] |
0705.3448 | Saul Stahl Professor | Saul Stahl | Mass in the Hyperbolic Plane | null | null | null | null | math.MG math-ph math.MP | null | The notions of mass and center of mass are extended to laminae of the
hyperbolic plane. The resulting formulae contain many surprises.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:22:10 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Stahl",
"Saul",
""
]
] |
0705.3449 | Anna Morozovska Nickolaevna | Anna N. Morozovska, Eugene A. Eliseev, and Sergei V. Kalinin | The Piezoresponse Force Microscopy of surface layers and thin films:
effective response and resolution function | 54 pages, 10 figures, 2 appendices, to be submitted to J. Appl. Phys | null | 10.1063/1.2785824 | null | cond-mat.mtrl-sci | null | Signal formation mechanism of Piezoresponse Force Microscopy of piezoelectric
surface layers and thin films on stiff and elastically matched substrates is
analyzed and thickness dependence of effective piezoelectric response, object
transfer function components and Rayleigh two-point resolution are derived.
Obtained exact series and simple Pade approximations can be applied for the
effective piezoresponse analytical calculations in the case of films capped on
different substrates. The effective piezoresponse is thickness dependent for
piezoelectric films on substrates with low dielectric permittivity (extrinsic
size effect), whereas the thickness dependence is essentially suppressed for
giant permittivity or metallic substrates. Thus implications of analysis for
ferroelectric data storage and device applications are discussed.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:31:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Morozovska",
"Anna N.",
""
],
[
"Eliseev",
"Eugene A.",
""
],
[
"Kalinin",
"Sergei V.",
""
]
] |
0705.3450 | Ivan Smith | Kenji Fukaya, Paul Seidel, Ivan Smith | The symplectic geometry of cotangent bundles from a categorical
viewpoint | 27 pages, 2 figures. Version 4 -- application added (to exact
Lagrangians in Euclidean space which are standard at infinity), results
sharpened for cotangent bundles of tori | null | null | null | math.SG math.AT | null | We describe various approaches to understanding Fukaya categories of
cotangent bundles. All of the approaches rely on introducing a suitable class
of noncompact Lagrangian submanifolds. We review the work of Nadler-Zaslow
(math/0604379, math/0612399) and the authors (math/0701783), before discussing
a new approach using family Floer cohomology and the ``wrapped Fukaya
category''. The latter, inspired by Viterbo's symplectic homology, emphasises
the connection to loop spaces, hence seems particularly suitable when trying to
extend the existing theory beyond the simply-connected case.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:50:25 GMT"
},
{
"version": "v2",
"created": "Sun, 27 May 2007 13:46:31 GMT"
},
{
"version": "v3",
"created": "Thu, 13 Sep 2007 06:51:01 GMT"
},
{
"version": "v4",
"created": "Wed, 26 Sep 2007 10:27:50 GMT"
}
] | 2007-09-26T00:00:00 | [
[
"Fukaya",
"Kenji",
""
],
[
"Seidel",
"Paul",
""
],
[
"Smith",
"Ivan",
""
]
] |
0705.3451 | Alexander Lutovinov | T.I.Larchenkova (1) and A.A.Lutovinov (2), ((1) Astro Space Center,
Lebedev Physical Institute, Russian Academy of Sciences, (2) Space Research
Institute, Russian Academy of Sciences) | On the Possibility of Observing the Shapiro Effect for Pulsars in
Globular Clusters | 26 pages, 9 figures | Astron.Lett.33:455-467,2007 | 10.1134/S1063773707070031 | null | astro-ph | null | For pulsars in globular clusters, we suggest using observations of the
relativistic time delay of their radiation in the gravitational eld of a
massive body (the Shapiro effect) located close to the line of sight to detect
and identify invisible compact objects and to study the distribution of both
visible and dark matter in globular clusters and various components of the
Galaxy. We have derived the dependences of the event probability on the
Galactic latitude and longitude of sources for two models of the mass
distribution in the Galaxy: the classical Bahcall-Soneira model and the more
recent Dehnen-Binney model. Using three globular clusters (M15, 47 Tuc, Terzan
5) as an example, we show that the ratios of the probability of the events due
to the passages of massive Galactic objects close to the line of sight to the
parameter f2 for pulsars in the globular clusters 47 Tuc and M15 are comparable
to those for close passages of massive objects in the clusters themselves and
are considerably higher than those for the cluster Terzan 5. We have estimated
the rates of such events. We have determined the number of objects near the
line of sight toward the pulsar that can produce a modulation of its pulse
arrival times characteristic of the effect under consideration; the population
of brown dwarfs in the Galactic disk, whose concentration is comparable to that
of the disk stars, has been taken into account for the first time.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:43:19 GMT"
},
{
"version": "v2",
"created": "Wed, 23 May 2007 20:38:06 GMT"
},
{
"version": "v3",
"created": "Sun, 8 Jul 2007 10:28:38 GMT"
}
] | 2009-11-16T00:00:00 | [
[
"Larchenkova",
"T. I.",
""
],
[
"Lutovinov",
"A. A.",
""
]
] |
0705.3452 | Bruno Bertrand | Bruno Bertrand (1) and Jan Govaerts (2,3) ((1) CP3, UCL,
Louvain-la-Neuve, Belgium, (2) Department of Physics, University of
Stellenbosch, Stellenbosch, Rep. South Africa, (3) International Chair in
Mathematical Physics and Applications (ICMPA-UNESCO), Cotonou, Rep. Benin) | Topologically Massive Gauge Theories and their Dual Factorised Gauge
Invariant Formulation | 1+7 pages, no figures | J.Phys.A40:F979-F986,2007 | 10.1088/1751-8113/40/46/F01 | CP3-07-14, ICMPA-MPA/2007/15 | hep-th | null | There exists a well-known duality between the Maxwell-Chern-Simons theory and
the self-dual massive model in 2+1 dimensions. This dual description has been
extended to topologically massive gauge theories (TMGT) in any dimension. This
Letter introduces an unconventional approach to the construction of this type
of duality through a reparametrisation of the master theory action. The dual
action thereby obtained preserves the same gauge symmetry structure as the
original theory. Furthermore, the dual action is factorised into a propagating
sector of massive gauge invariant variables and a sector with gauge variant
variables defining a pure topological field theory. Combining results obtained
within the Lagrangian and Hamiltonian formulations, a new completed structure
for a gauge invariant dual factorisation of TMGT is thus achieved.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:50:26 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bertrand",
"Bruno",
""
],
[
"Govaerts",
"Jan",
""
]
] |
0705.3453 | Abhijit Champanerkar | Abhijit Champanerkar, Ilya Kofman, Neal Stoltzfus | Graphs on surfaces and Khovanov homology | 8 pages, 5 figures | Algebr. Geom. Topol. 7 (2007) 1531-1540 | 10.2140/agt.2007.7.1531 | null | math.GT math.CO math.QA | null | Oriented ribbon graphs (dessins d'enfant) are graphs embedded in oriented
surfaces. A quasi-tree of a ribbon graph is a spanning subgraph with one face,
which is described by an ordered chord diagram. We show that for any link
diagram $L$, there is an associated ribbon graph whose quasi-trees correspond
bijectively to spanning trees of the graph obtained by checkerboard coloring
$L$. This correspondence preserves the bigrading used for the spanning tree
model of Khovanov homology, whose Euler characteristic is the Jones polynomial
of $L$. Thus, Khovanov homology can be expressed in terms of ribbon graphs,
with generators given by ordered chord diagrams.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 19:50:53 GMT"
}
] | 2016-01-20T00:00:00 | [
[
"Champanerkar",
"Abhijit",
""
],
[
"Kofman",
"Ilya",
""
],
[
"Stoltzfus",
"Neal",
""
]
] |
0705.3454 | Joshua Bodyfelt | J.D. Bodyfelt, M. Hiller and T. Kottos | Engineering fidelity echoes in Bose-Hubbard Hamiltonians | 6 pages, use epl2.cls class, 5 figures Cross reference with nlin,
quant-phys | Europhysics Letters 78 (2007) 50003 | 10.1209/0295-5075/78/50003 | null | cond-mat.other | null | We analyze the fidelity decay for a system of interacting bosons described by
a Bose-Hubbard Hamiltonian. We find echoes associated with "non-universal"
structures that dominate the energy landscape of the perturbation operator.
Despite their classical origin, these echoes persist deep into the quantum
(perturbative) regime and can be described by an improved random matrix
modeling. In the opposite limit of strong perturbations (and high enough
energies), classical considerations reveal the importance of self-trapping
phenomena in the echo efficiency.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:33:10 GMT"
}
] | 2008-07-02T00:00:00 | [
[
"Bodyfelt",
"J. D.",
""
],
[
"Hiller",
"M.",
""
],
[
"Kottos",
"T.",
""
]
] |
0705.3455 | J\"org P. Dietrich | J. P. Dietrich, T. Erben, G. Lamer, P. Schneider, A. Schwope, J.
Hartlap, M. Maturi | BLOX: The Bonn Lensing, Optical, and X-ray selected galaxy clusters --
I. Cluster catalog construction | Accepted for publication in Astronomy & Astrophysics, 14 pages, 5
figures. The cluster catalogs are available at
http://www.eso.org/~jdietric/publications.html | null | 10.1051/0004-6361:20077281 | null | astro-ph | null | The mass function of galaxy clusters is an important cosmological probe.
Differences in the selection method could potentially lead to biases when
determining the mass function. From the optical and X-ray data of the
XMM-Newton Follow-Up Survey, we obtained a sample of galaxy cluster candidates
using weak gravitational lensing, the optical Postman matched filter method,
and a search for extended X-ray sources. We developed our weak-lensing search
criteria by testing the performance of the aperture mass statistic on realistic
ray-tracing simulations matching our survey parameters and by comparing two
filter functions. We find that the dominant noise source for our survey is
shape noise at almost all significance levels and that spurious cluster
detections due to projections of large-scale structures are negligible, except
possibly for highly significantly detected peaks. Our full cluster catalog has
155 cluster candidates, 116 found with the Postman matched filter, 59 extended
X-ray sources, and 31 shear selected potential clusters. Most of these cluster
candidates were not previously known. The present catalog will be a solid
foundation for studying possible selection effects in either method.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:00:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dietrich",
"J. P.",
""
],
[
"Erben",
"T.",
""
],
[
"Lamer",
"G.",
""
],
[
"Schneider",
"P.",
""
],
[
"Schwope",
"A.",
""
],
[
"Hartlap",
"J.",
""
],
[
"Maturi",
"M.",
""
]
] |
0705.3456 | Jens Eisert | Christopher M. Dawson, Jens Eisert, Tobias J. Osborne | Unifying variational methods for simulating quantum many-body systems | 5 pages, 3 figures, replaced with published version | Phys. Rev. Lett. 100, 130501 (2008) | 10.1103/PhysRevLett.100.130501 | null | quant-ph cond-mat.str-el | null | We introduce a unified formulation of variational methods for simulating
ground state properties of quantum many-body systems. The key feature is a
novel variational method over quantum circuits via infinitesimal unitary
transformations, inspired by flow equation methods. Variational classes are
represented as efficiently contractible unitary networks, including the
matrix-product states of density matrix renormalization, multiscale
entanglement renormalization (MERA) states, weighted graph states, and quantum
cellular automata. In particular, this provides a tool for varying over classes
of states, such as MERA, for which so far no efficient way of variation has
been known. The scheme is flexible when it comes to hybridizing methods or
formulating new ones. We demonstrate the functioning by numerical
implementations of MERA, matrix-product states, and a new variational set on
benchmarks.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 18:50:48 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jan 2008 11:49:03 GMT"
},
{
"version": "v3",
"created": "Mon, 31 Mar 2008 18:39:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dawson",
"Christopher M.",
""
],
[
"Eisert",
"Jens",
""
],
[
"Osborne",
"Tobias J.",
""
]
] |
0705.3457 | Vladimir Nikiforov | Vladimir Nikiforov | The spectral radius of subgraphs of regular graphs | null | null | null | null | math.CO | null | We give a bound on the spectral radius of subgraphs of regular graphs with
given order and diameter. We give a lower bound on the smallest eigenvalue of a
nonbipartite regular graph of given order and diameter.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:03:02 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Nikiforov",
"Vladimir",
""
]
] |
0705.3458 | Ilya S. Kofman | Abhijit Champanerkar, Ilya Kofman, Neal Stoltzfus | Quasi-tree expansion for the Bollob\'as-Riordan-Tutte polynomial | This version to be published in the Bulletin of the London
Mathematical Society. 17 pages, 4 figures | Bulletin of the London Mathematical Society, 43 (2011), no. 5,
972-984 | 10.1112/blms/bdr034 | null | math.CO math.GT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Oriented ribbon graphs (dessins d'enfant) are graphs embedded in oriented
surfaces. The Bollob\'as-Riordan-Tutte polynomial is a three-variable
polynomial that extends the Tutte polynomial to oriented ribbon graphs. A
quasi-tree of a ribbon graph is a spanning subgraph with one face, which is
described by an ordered chord diagram. We generalize the spanning tree
expansion of the Tutte polynomial to a quasi-tree expansion of the
Bollob\'as-Riordan-Tutte polynomial.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:04:08 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Jun 2011 21:57:40 GMT"
}
] | 2016-08-02T00:00:00 | [
[
"Champanerkar",
"Abhijit",
""
],
[
"Kofman",
"Ilya",
""
],
[
"Stoltzfus",
"Neal",
""
]
] |
0705.3459 | Jonathan Williams | Jonathan P. Williams and Eric Gaidos (Univ. of Hawaii Manoa) | On the likelihood of supernova enrichment of protoplanetary disks | accepted to ApJ Letters | null | 10.1086/519972 | null | astro-ph | null | We estimate the likelihood of direct injection of supernova ejecta into
protoplanetary disks using a model in which the number of stars with disks
decreases linearly with time, and clusters expand linearly with time such that
their surface density is independent of stellar number. The similarity of disk
dissipation and main sequence lifetimes implies that the typical supernova
progenitor is very massive, ~ 75-100 Msun. Such massive stars are found only in
clusters with > 10^4 members. Moreover, there is only a small region around a
supernova within which disks can survive the blast yet be enriched to the level
observed in the Solar System. These two factors limit the overall likelihood of
supernova enrichment of a protoplanetary disk to < 1%. If the presence of short
lived radionucleides in meteorites is to be explained in this way, however, the
Solar System most likely formed in one of the largest clusters in the Galaxy,
more than two orders of magnitude greater than Orion, where multiple supernovae
impacted many disks in a short period of time.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 02:04:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Williams",
"Jonathan P.",
"",
"Univ. of Hawaii Manoa"
],
[
"Gaidos",
"Eric",
"",
"Univ. of Hawaii Manoa"
]
] |
0705.3460 | Joseph Conlon | Joseph P. Conlon, Fernando Quevedo | Astrophysical and Cosmological Implications of Large Volume String
Compactifications | 31 pages, 2 figures; v2. refs added | JCAP 0708:019,2007 | 10.1088/1475-7516/2007/08/019 | DAMTP-2007-43 | hep-ph astro-ph hep-th | null | We study the spectrum, couplings and cosmological and astrophysical
implications of the moduli fields for the class of Calabi-Yau IIB string
compactifications for which moduli stabilisation leads to an exponentially
large volume V ~ 10^{15} l_s^6 and an intermediate string scale m_s ~
10^{11}GeV, with TeV-scale observable supersymmetry breaking. All K\"ahler
moduli except for the overall volume are heavier than the susy breaking scale,
with m ~ ln(M_P/m_{3/2}) m_{3/2} ~ (\ln(M_P/m_{3/2}))^2 m_{susy} ~ 500 TeV and,
contrary to standard expectations, have matter couplings suppressed only by the
string scale rather than the Planck scale. These decay to matter early in the
history of the universe, with a reheat temperature T ~ 10^7 GeV, and are free
from the cosmological moduli problem (CMP). The heavy moduli have a branching
ratio to gravitino pairs of 10^{-30} and do not suffer from the gravitino
overproduction problem. The overall volume modulus is a distinctive feature of
these models and is an M_{planck}-coupled scalar of mass m ~ 1 MeV and subject
to the CMP. A period of thermal inflation can help relax this problem. This
field has a lifetime ~ 10^{24}s and can contribute to dark matter. It may be
detected through its decays to 2\gamma or e^+e^-. If accessible the e^+e^-
decay mode dominates, with Br(\chi \to 2 \gamma) suppressed by a factor
(ln(M_P/m_{3/2}))^2. We consider the potential for detection of this field
through different astrophysical sources and find that the observed gamma-ray
background constrains \Omega_{\chi} <~ 10^{-4}. The decays of this field may
generate the 511 keV emission line from the galactic centre observed by
INTEGRAL/SPI.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:20:17 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Jun 2007 16:04:30 GMT"
}
] | 2009-04-21T00:00:00 | [
[
"Conlon",
"Joseph P.",
""
],
[
"Quevedo",
"Fernando",
""
]
] |
0705.3461 | Yaroslav Kartashov | Yaroslav V. Kartashov, Victor A. Vysloukh, Lluis Torner | Soliton emission in amplifying optical lattice surfaces | 14 pages, 4 figures, to appear in Optics Letters | Optics Letters 32, 2061 (2007) | 10.1364/OL.32.002061 | null | physics.optics nlin.PS | null | We address surface solitons supported by the interface of optical lattices
imprinted in saturable media with surface-localized gain. The nonlinearity
saturation puts restrictions on the maximal energy flow carried by surface
solitons. As a consequence, the presence of thin amplifying layer near the
surface results in the controllable emission of solitons towards the lattice at
angles depending on the amplification rate and on lattice depth.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:12:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kartashov",
"Yaroslav V.",
""
],
[
"Vysloukh",
"Victor A.",
""
],
[
"Torner",
"Lluis",
""
]
] |
0705.3462 | Berkeley Zych | Berkeley J. Zych, Michael T. Murphy, Max Pettini, Paul C. Hewett, Emma
V. Ryan-Weber, Sara L. Ellison | The host galaxies of strong CaII QSO absorption systems at z<0.5 | Accepted for publication in MNRAS, 14 pages, 9 figures. Version with
full resolution images available at
http://www.ast.cam.ac.uk/~bjz/papers/Zych_etal_2007a.pdf | Mon.Not.Roy.Astron.Soc.379:1409-1422,2007 | 10.1111/j.1365-2966.2007.12015.x | null | astro-ph | null | We present new imaging and spectroscopic observations of the fields of five
QSOs with very strong intervening CaII absorption systems at redshifts z<0.5
selected from the Sloan Digital Sky Survey. Recent studies of these very rare
absorbers indicate that they may be related to damped Lyman alpha systems
(DLAs). In all five cases we identify a galaxy at the redshift of the CaII
system with impact parameters up to ~24 kpc. In four out of five cases the
galaxies are luminous (L ~L*), metal-rich (Z ~Zsun), massive (velocity
dispersion, sigma ~100 km/s) spirals. Their star formation rates, deduced from
Halpha emission, are high, in the range SFR = 0.3 - 30 Msun/yr. In our
analysis, we paid particular attention to correcting the observed emission line
fluxes for stellar absorption and dust extinction. We show that these effects
are important for a correct SFR estimate; their neglect in previous low-z
studies of DLA-selected galaxies has probably led to an underestimate of the
star formation activity in at least some DLA hosts. We discuss possible links
between CaII-selected galaxies and DLAs and outline future observations which
will help clarify the relationship between these different classes of QSO
absorbers.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 14:21:05 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Zych",
"Berkeley J.",
""
],
[
"Murphy",
"Michael T.",
""
],
[
"Pettini",
"Max",
""
],
[
"Hewett",
"Paul C.",
""
],
[
"Ryan-Weber",
"Emma V.",
""
],
[
"Ellison",
"Sara L.",
""
]
] |
0705.3463 | Alexander Plyukhin V | A.V. Plyukhin and A.M. Froese | Transient rectification of Brownian diffusion with asymmetric initial
distribution | null | Phys. Rev. E 76, 031121 (2007) | 10.1103/PhysRevE.76.031121 | null | cond-mat.stat-mech | null | In an ensemble of non-interacting Brownian particles, a finite systematic
average velocity may temporarily develop, even if it is zero initially. The
effect originates from a small nonlinear correction to the dissipative force,
causing the equation for the first moment of velocity to couple to moments of
higher order. The effect may be relevant when a complex system dissociates in a
viscous medium with conservation of momentum.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:20:32 GMT"
},
{
"version": "v2",
"created": "Fri, 25 May 2007 18:24:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Plyukhin",
"A. V.",
""
],
[
"Froese",
"A. M.",
""
]
] |
0705.3464 | Eva Noyola | Eva Noyola (1,2) and Karl Gebhardt (2), ((1) MPE, (2) UT Austin) | Surface Brightness Profiles for a sample of LMC, SMC and Fornax galaxy
Globular Clusters | 15 pages, 9 figures, AJ accepted | Astron.J.134:912-925,2007 | 10.1086/520061 | null | astro-ph | null | We use Hubble Space Telescope archival images to measure central surface
brightness profiles of globular clusters around satellite galaxies of the Milky
Way. We report results for 21 clusters around the LMC, 5 around the SMC, and 4
around the Fornax dwarf galaxy. The profiles are obtained using a recently
developed technique based on measuring integrated light, which is tested on an
extensive simulated dataset. Our results show that for 70% of the sample, the
central photometric points of our profiles are brighter than previous
measurements using star counts with deviations as large as 2 mag/arcsec^2.
About 40% of the objects have central profiles deviating from a flat central
core, with central logarithmic slopes continuously distributed between -0.2 and
-1.2. These results are compared with those found for a sample of Galactic
clusters using the same method. We confirm the known correlation in which
younger clusters tend to have smaller core radii, and we find that they also
have brighter central surface brightness values. This seems to indicate that
globular clusters might be born relatively concentrated, and that a profile
with extended flat cores might not be the ideal choice for initial profiles in
theoretical models.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:20:38 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Noyola",
"Eva",
"",
"MPE",
"UT Austin"
],
[
"Gebhardt",
"Karl",
"",
"UT Austin"
]
] |
0705.3465 | Joshua Younger | Joshua D. Younger (1,2), Greg L. Bryan (3) ((1) Columbia Astrophysics
Lab; (2) Harvard/CfA; (3) Department of Astronomy, Columbia University) | Cosmological Simulations of the Preheating Scenario for Galaxy Cluster
Formation: Comparison to Analytic Models and Observations | 11 pages, 13 figures, accepted for publication in ApJ | Astrophys.J.666:647-657,2007 | 10.1086/520619 | null | astro-ph | null | We perform a set of non--radiative cosmological simulations of a preheated
intracluster medium in which the entropy of the gas was uniformly boosted at
high redshift. The results of these simulations are used first to test the
current analytic techniques of preheating via entropy input in the smooth
accretion limit. When the unmodified profile is taken directly from
simulations, we find that this model is in excellent agreement with the results
of our simulations. This suggests that preheated efficiently smoothes the
accreted gas, and therefore a shift in the unmodified profile is a good
approximation even with a realistic accretion history. When we examine the
simulation results in detail, we do not find strong evidence for entropy
amplification, at least for the high-redshift preheating model adopted here. In
the second section of the paper, we compare the results of the preheating
simulations to recent observations. We show -- in agreement with previous work
-- that for a reasonable amount of preheating, a satisfactory match can be
found to the mass-temperature and luminosity-temperature relations. However --
as noted by previous authors -- we find that the entropy profiles of the
simulated groups are much too flat compared to observations. In particular,
while rich clusters converge on the adiabatic self--similar scaling at large
radius, no single value of the entropy input during preheating can
simultaneously reproduce both the core and outer entropy levels. As a result,
we confirm that the simple preheating scenario for galaxy cluster formation, in
which entropy is injected universally at high redshift, is inconsistent with
observations.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:26:08 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Younger",
"Joshua D.",
""
],
[
"Bryan",
"Greg L.",
""
]
] |
0705.3466 | Travis C. Brooks | Travis C. Brooks | Open Access Publishing in Particle Physics: A Brief Introduction for the
non-Expert | null | null | null | SLAC-PUB-12507 | cs.DL | null | Open Access to particle physics literature does not sound particularly new or
exciting, since particle physicists have been reading preprints for decades,
and arXiv.org for 15 years. However new movements in Europe are attempting to
make the peer-reviewed literature of the field fully Open Access. This is not a
new movement, nor is it restricted to this field. However, given the field's
history of preprints and eprints, it is well suited to a change to a fully Open
Access publishing model. Data shows that 90% of HEP published literature is
freely available online, meaning that HEP libraries have little need for
expensive journal subscriptions. As libraries begin to cancel journal
subscriptions, the peer review process will lose its primary source of funding.
Open Access publishing models can potentially address this issue. European
physicists and funding agencies are proposing a consortium, SCOAP3, that might
solve many of the objections to traditional Open Access publishing models in
Particle Physics. These proposed changes should be viewed as a starting point
for a serious look at the field's publication model, and are at least worthy of
attention, if not adoption.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:28:47 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Brooks",
"Travis C.",
""
]
] |
0705.3467 | Bruno Bertrand | Bruno Bertrand (CP3, UCL, Louvain-la-Neuve, Belgium) | New insights into abelian topologically massive gauge theories | To appear in the Proceedings of the IV Summer School in Modern
Mathematical Physics, 3-14 September 2006, Belgrade, Serbia, 8 pages | null | null | CP3-07-06 | hep-th | null | Abelian topologically massive gauge theories (TMGT) provide a topological
mechanism to generate mass for any p-tensor boson in any dimension. Within the
Hamiltonian formulation, the embedded topological field theory (TFT) is not
made manifest. We therefore introduce a gauge invariant factorization of the
classical phase space in two orthogonal sectors. The first of these sectors is
that of gauge invariant dynamical variables with massive excitations. The
second is that of a decoupled TFT. Through canonical quantization, a
factorization of quantum states arises, enabling the projection from TMGT onto
topological quantum field theories in a most transparent way.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:51:39 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Bertrand",
"Bruno",
"",
"CP3, UCL, Louvain-la-Neuve, Belgium"
]
] |
0705.3468 | Neng-Fa Zhou | Neng-Fa Zhou, Taisuke Sato, and Yi-Dong Shen | Linear Tabling Strategies and Optimizations | 29 pages, 1 figure, TPLP | null | null | null | cs.PL | null | Recently, the iterative approach named linear tabling has received
considerable attention because of its simplicity, ease of implementation, and
good space efficiency. Linear tabling is a framework from which different
methods can be derived based on the strategies used in handling looping
subgoals. One decision concerns when answers are consumed and returned. This
paper describes two strategies, namely, {\it lazy} and {\it eager} strategies,
and compares them both qualitatively and quantitatively. The results indicate
that, while the lazy strategy has good locality and is well suited for finding
all solutions, the eager strategy is comparable in speed with the lazy strategy
and is well suited for programs with cuts. Linear tabling relies on depth-first
iterative deepening rather than suspension to compute fixpoints. Each cluster
of inter-dependent subgoals as represented by a top-most looping subgoal is
iteratively evaluated until no subgoal in it can produce any new answers. Naive
re-evaluation of all looping subgoals, albeit simple, may be computationally
unacceptable. In this paper, we also introduce semi-naive optimization, an
effective technique employed in bottom-up evaluation of logic programs to avoid
redundant joins of answers, into linear tabling. We give the conditions for the
technique to be safe (i.e. sound and complete) and propose an optimization
technique called {\it early answer promotion} to enhance its effectiveness.
Benchmarking in B-Prolog demonstrates that with this optimization linear
tabling compares favorably well in speed with the state-of-the-art
implementation of SLG.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:52:42 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Zhou",
"Neng-Fa",
""
],
[
"Sato",
"Taisuke",
""
],
[
"Shen",
"Yi-Dong",
""
]
] |
0705.3469 | Joe Helmboldt | J. F. Helmboldt | The HI content of elliptical and lenticular galaxies with recent star
formation | Accepted by MNRAS | Mon.Not.Roy.Astron.Soc.379:1227-1236,2007 | 10.1111/j.1365-2966.2007.12022.x | null | astro-ph | null | As a first step toward constraining the efficiency of the star formation
episodes that lead to elliptical (E) and lenticular (S0) K+A galaxies, a survey
for HI within a sample of E and S0 K+A galaxies and their likely progenitors
(i.e., actively star forming E and S0 galaxies) has been conducted with the
NRAO Green Bank Telescope (GBT). The sample was taken from a larger parent
sample drawn from the Sloan Digital Sky Survey (SDSS). Here, the GBT data and
initial results are discussed. Over half (19 out of 30) of all observed
galaxies have detectable 21-cm emission. It was found that both the K+A and
star forming early-type (SFE) galaxies were on average more gas poor than disk
galaxies at the same luminosity while being more gas rich than more typical E
and S0 galaxies with detected 21-cm emission. The gas richness of K+A galaxies
appears to be similar to that of SFE galaxies. The star formation rates and
estimated star formation time scales of the SFE galaxies imply that they are
capable of only marginally changing their atomic hydrogen content. Follow-up
observations are required to explore these same issues in terms of molecular
gas, which is more likely to actively participate in the star formation
process. Kinematic data for the HI gas, the warm ionised gas, and the stars
within the galaxies combined with the SDSS $g$ and $i$ band surface brightness
profiles imply that the atomic hydrogen is most likely spatially coincident
with the star forming regions within ~1 kpc of the galaxies' centres.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 20:57:01 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Helmboldt",
"J. F.",
""
]
] |
0705.3470 | Nicola Romanazzi | Nicola Romanazzi (Drexel U.), Marc Lefranc (PhLAM), Robert Gilmore
(Drexel U.) | Embeddings of low-dimensional strange attractors: Topological invariants
and degrees of freedom | null | Phys. Rev. E 75, 066214 (2007) | 10.1103/PhysRevE.75.066214 | null | nlin.CD | null | When a low dimensional chaotic attractor is embedded in a three dimensional
space its topological properties are embedding-dependent. We show that there
are just three topological properties that depend on the embedding: parity,
global torsion, and knot type. We discuss how they can change with the
embedding. Finally, we show that the mechanism that is responsible for creating
chaotic behavior is an invariant of all embeddings. These results apply only to
chaotic attractors of genus one, which covers the majority of cases in which
experimental data have been subjected to topological analysis. This means that
the conclusions drawn from previous analyses, for example that the mechanism
generating chaotic behavior is a Smale horseshoe mechanism, a reverse
horseshoe, a gateau roule, an S-template branched manifold, ..., are not
artifacts of the embedding chosen for the analysis.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 21:03:57 GMT"
}
] | 2007-07-26T00:00:00 | [
[
"Romanazzi",
"Nicola",
"",
"Drexel U."
],
[
"Lefranc",
"Marc",
"",
"PhLAM"
],
[
"Gilmore",
"Robert",
"",
"Drexel U."
]
] |
0705.3471 | Mason A. Porter | Mason A. Porter, Chiara Daraio, Eric B. Herbold, Ivan Szelengowicz,
and P. G. Kevrekidis | Highly Nonlinear Solitary Waves in Periodic Dimer Granular Chains | 4.2 pages, 3 figures (each with multiple panels); adjustments in
title, text, and figures; typos corrected; to appear in Physical Review E
(rapid communication) | null | 10.1103/PhysRevE.77.015601 | null | nlin.PS cond-mat.mtrl-sci cond-mat.soft | null | We report the propagation of highly nonlinear solitary waves in
heterogeneous, periodic granular media using experiments, numerical
simulations, and theoretical analysis. We examine periodic arrangements of
particles in experiments in which stiffer/heavier beads (stainless steel) are
alternated with softer/lighter ones (PTFE beads). We find excellent agreement
between experiments and numerics in a model with Hertzian interactions between
adjacent beads, which in turn agrees very well with a theoretical analysis of
the model in the long-wavelength regime that we derive for heterogeneous
environments and general bead interactions. Our analysis encompasses
previously-studied examples as special cases and also provides key insights on
the influence of the dimer lattice on the properties (width and propagation
speed) of the obtained highly nonlinear wave solutions.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 21:05:31 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Sep 2007 23:28:15 GMT"
},
{
"version": "v3",
"created": "Fri, 14 Dec 2007 22:12:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Porter",
"Mason A.",
""
],
[
"Daraio",
"Chiara",
""
],
[
"Herbold",
"Eric B.",
""
],
[
"Szelengowicz",
"Ivan",
""
],
[
"Kevrekidis",
"P. G.",
""
]
] |
0705.3472 | Sushil Singh Chauhan | Satyaki Bhattacharya, Sushil S. Chauhan, Brajesh C. Choudhary,
Debajyoti Choudhury | Search for Excited Quarks in $q\bar{q} \to \gamma\gamma$ at the LHC | 11 pages, 11 figures | Phys.Rev.D76:115017,2007 | 10.1103/PhysRevD.76.115017 | null | hep-ph | null | If quarks are composite particles, then excited states are expected to play a
r\^ole in the Large Hadron Collider phenomena. Concentrating on virtual
effects, and using a large part of the CMS detection criteria, we present here
a realistic examination of their effect in diphoton production at the LHC. For
various luminosities, we present the 99 % confidence limit (CL) achievable in
$\Lambda-M_{q*}$ parameter space where $\Lambda$ is the compositeness scale and
M_{q^*} the mass of the state. For a q^* of mass 0.5 TeV, $\Lambda \leq 1.55
(2.95)$ can be excluded at 99% CL with 30 (200)${\rm fb}^{-1}$ integrated
luminosity.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:45:07 GMT"
},
{
"version": "v2",
"created": "Sat, 28 Jul 2007 11:50:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bhattacharya",
"Satyaki",
""
],
[
"Chauhan",
"Sushil S.",
""
],
[
"Choudhary",
"Brajesh C.",
""
],
[
"Choudhury",
"Debajyoti",
""
]
] |
0705.3473 | Alex Barnett | A. H. Barnett and P. R. Moorcroft | Analytic steady-state space use patterns and rapid computations in
mechanistic home range analysis | 14 pages, 7 figures, submit to J. Math. Biol | null | null | null | q-bio.QM | null | Mechanistic home range models are important tools in modeling animal dynamics
in spatially-complex environments. We introduce a class of stochastic models
for animal movement in a habitat of varying preference. Such models interpolate
between spatially-implicit resource selection analysis (RSA) and
advection-diffusion models, possessing these two models as limiting cases. We
find a closed-form solution for the steady-state (equilibrium) probability
distribution u* using a factorization of the redistribution operator into
symmetric and diagonal parts. How space use is controlled by the preference
function w then depends on the characteristic width of the redistribution
kernel: when w changes rapidly compared to this width, u* ~ w, whereas on
global scales large compared to this width, u* ~ w^2. We analyse the behavior
at discontinuities in w which occur at habitat type boundaries. We simulate the
dynamics of space use given two-dimensional prey-availability data and explore
the effect of the redistribution kernel width. Our factorization allows such
numerical simulations to be done extremely fast; we expect this to aid the
computationally-intensive task of model parameter fitting and inverse modeling.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 21:53:04 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Barnett",
"A. H.",
""
],
[
"Moorcroft",
"P. R.",
""
]
] |
0705.3474 | Joseph Turnbull | Joseph Turnbull and Massimo Boninsegni | Molecular hydrogen isotopes adsorbed on krypton-preplated graphite:
Quantum Monte Carlo simulations | 7 pages, 7 figures | Phys. Rev. B 76, 104524 (2007) | 10.1103/PhysRevB.76.104524 | null | cond-mat.stat-mech | null | Adsorption of ortho-deuterium and para-hydrogen films on a graphite
substrate, pre-plated with a single atomic layer of krypton, is studied
theoretically by means of quantum Monte Carlo simulations at low temperature.
Our model explicitly includes substrate corrugation. Energetic and structural
properties of these adsorbed films are computed for a range of hydrogen
coverages. Thermodynamically stable adsorbed films are solid, with no clear
evidence of any liquid-like phase. Quantum exchanges of ortho-deuterium and
para-hydrogen are essentially absent in this system, down to zero temperature;
consequently, this system displays no superfluidity in this limit. Our
simulations provide evidence of a stable domain wall fluid at low temperature,
consistently with recent experimental observations.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 21:56:22 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 14:26:12 GMT"
},
{
"version": "v3",
"created": "Wed, 11 Jul 2007 05:27:45 GMT"
}
] | 2007-09-28T00:00:00 | [
[
"Turnbull",
"Joseph",
""
],
[
"Boninsegni",
"Massimo",
""
]
] |
0705.3475 | Mauricio Bellini | Mariano Anabitarte (Mar del Plata University - CONICET), Mauricio
Bellini (Mar del Plata University - CONICET) | Gauge invariant metric fluctuations in the early universe from STM
theory of gravity: nonperturbative formalism | version accepted in Physics Letters B | Phys.Lett.B652:233-237,2007 | 10.1016/j.physletb.2007.07.028 | null | gr-qc hep-th | null | We develop a nonperturbative quantum field formalism to describe scalar
gauge-invariant metric flucturations in the early universe from a 5D apparent
(Ricci flat) vacuum.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:04:08 GMT"
},
{
"version": "v2",
"created": "Wed, 30 May 2007 20:19:17 GMT"
},
{
"version": "v3",
"created": "Fri, 6 Jul 2007 17:27:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Anabitarte",
"Mariano",
"",
"Mar del Plata University - CONICET"
],
[
"Bellini",
"Mauricio",
"",
"Mar del Plata University - CONICET"
]
] |
0705.3476 | Mikhail Dubrovin | M.S. Dubrovin | D Hadronic Analyses at CLEO | 6 pages, 9 figures, XLII Rencontres de Moriond, La Thuile, Italy,
17-24 March 2007 | null | null | null | hep-ex | null | The CLEO-c results on D meson production and hadronic decays obtained with
currently available data sets are presented.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:20:40 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Dubrovin",
"M. S.",
""
]
] |
0705.3477 | Ho-Tsang Ng | H. T. Ng and K. Burnett | Vacuum Fluctuations induced Entanglement between Two Mesoscopic Systems | 4 pages, 4 figures | New J. Phys. 10 123014 (2008) | 10.1088/1367-2630/10/12/123014 | null | quant-ph | null | We study the dynamics of a pair of molecular ensembles trapped inside a
superconducting resonator through which they are strongly coupled via a
microwave field mode. We find that entanglement can be generated via "vacuum
fluctuations" even when the molecules and cavity field are initially prepared
in their ground state. This entanglement is created in a relatively short time
and without the need for further manipulation of the system. It does,
therefore, provide a convenient scheme to entangle two mesoscopic systems, and
may well be useful quantum information processing.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:21:40 GMT"
}
] | 2011-08-02T00:00:00 | [
[
"Ng",
"H. T.",
""
],
[
"Burnett",
"K.",
""
]
] |
0705.3478 | Robert Quimby | Robert M. Quimby, J. Craig Wheeler, Peter H\"oflich, Carl W. Akerlof,
Peter J. Brown and Eli S. Rykoff | SN 2006bp: Probing the Shock Breakout of a Type II-P Supernova | ApJ accepted, 43 pages | Astrophys.J.666:1093-1107,2007 | 10.1086/520532 | null | astro-ph | null | HET optical spectroscopy and unfiltered ROTSE-III photometry spanning the
first 11 months since explosion of the Type II-P SN 2006bp are presented. Flux
limits from the days before discovery combined with the initial rapid
brightening suggest the supernova was first detected just hours after shock
breakout. Optical spectra obtained about 2 days after breakout exhibit narrow
emission lines corresponding to HeII 4200, HeII 4686, and CIV 5805 in the rest
frame, and these features persist in a second observation obtained 5 hours
later; however, these emission lines are not detected the following night nor
in subsequent observations. We suggest that these lines emanate from material
close to the explosion site, possibly in the outer layers of the progenitor
that have been ionized by the high energy photons released at shock breakout. A
P-Cygni profile is observed around 4450 A in the +2 and +3 day spectra.
Previous studies have attributed this feature to high velocity H-beta, but we
discuss the possibility that this profile is instead due to HeII 4687. Further
HET observations (14 nights in total) covering the spectral evolution across
the photometric plateau up to 73 days after breakout and during the nebular
phase around day +340 are presented, and expansion velocities are derived for
key features. The measured decay slope for the unfiltered light curve is 0.0073
+/- 0.0004 mag/day between days +121 and +335, which is significantly slower
than the decay of rate 56Co. We combine our HET measurements with published
X-ray, UV, and optical data to obtain a quasi-bolometric light curve through
day +60. We see a slow cooling over the first 25 days, but no sign of an early
sharp peak; any such feature from the shock breakout must have lasted less than
~1 day.[ABRIDGED]
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:21:55 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Quimby",
"Robert M.",
""
],
[
"Wheeler",
"J. Craig",
""
],
[
"Höflich",
"Peter",
""
],
[
"Akerlof",
"Carl W.",
""
],
[
"Brown",
"Peter J.",
""
],
[
"Rykoff",
"Eli S.",
""
]
] |
0705.3479 | Rubens Ramos Viana | Joao Batista Rosa Silva and Rubens Viana Ramos | Implementation of non-local XOR function for coherent-state qubit | 12 pages and 6 figures | null | null | null | quant-ph | null | This work describes how to implement a non-local xor function for
coherent-state qubit using only linear optics. The setup proposed does not use
gates based on teleportation and it has probability of success equal to 0.5, in
the lossless case, when the necessary entangled state is available. The key
element that makes possible the realization of the non-local xor function is a
tripartite GHZ-type entangled coherent state. Its generation is proposed
firstly using an ideal lossless setup and secondly considering the decoherence
caused by losses in the optical devices.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:22:13 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Silva",
"Joao Batista Rosa",
""
],
[
"Ramos",
"Rubens Viana",
""
]
] |
0705.3480 | Petr Chaloupka | Petr Chaloupka (for STAR collaboration) | pi-Xi correlations in d+Au and Au+Au collisions at STAR | prepared for the poster-session proceedings of the 19th International
Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006) | null | 10.1142/S0218301307007726 | null | nucl-ex | null | Qualitative comparison of source sizes from pi-Xi correlations analyses in
d+Au and Au+Au collisions at sqrt(s_NN)=200G GeV and sqrt(s_NN)=62 GeV is
presented. For the most central Au+Au collisions at sqrt(s_NN)=200 GeV we
report first quantitative results concerning size of the pi-Xi source and
relative shift of the average emission points between pi and Xi showing that
the homogeneity region of Xi source is smaller then that of pion and
significantly shifted in the transverse direction.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:52:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chaloupka",
"Petr",
"",
"for STAR collaboration"
]
] |
0705.3481 | Matyas Vasuth | M\'aty\'as Vas\'uth and J\'anos Maj\'ar | Gravitational waveforms for finite mass binaries | 7 pages, to appear in IJMPA; corrected typos | Int.J.Mod.Phys.A22:2405-2414,2007 | 10.1142/S0217751X07036488 | null | gr-qc | null | One of the promising sources of gravitational radiation is a binary system
composed of compact stars. It is an important question how the rotation of the
bodies and the eccentricity of the orbit affect the detectable signal. Here we
present a method to evaluate the gravitational wave polarization states for
inspiralling compact binaries with comparable mass. We consider eccentric
orbits and the spin-orbit contribution in the case of one spinning object up to
1.5 post-Newtonian order. For circular orbits our results are in agreement with
existing calculations.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 22:54:24 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 19:42:57 GMT"
}
] | 2010-10-27T00:00:00 | [
[
"Vasúth",
"Mátyás",
""
],
[
"Majár",
"János",
""
]
] |
0705.3482 | Jan Johannes | Jan Johannes | Deconvolution with unknown error distribution | Published in at http://dx.doi.org/10.1214/08-AOS652 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org) | Annals of Statistics 2009, Vol. 37, No. 5A, 2301-2323 | 10.1214/08-AOS652 | IMS-AOS-AOS652 | math.ST stat.TH | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the problem of estimating a density $f_X$ using a sample
$Y_1,...,Y_n$ from $f_Y=f_X\star f_{\epsilon}$, where $f_{\epsilon}$ is an
unknown density. We assume that an additional sample
$\epsilon_1,...,\epsilon_m$ from $f_{\epsilon}$ is observed. Estimators of
$f_X$ and its derivatives are constructed by using nonparametric estimators of
$f_Y$ and $f_{\epsilon}$ and by applying a spectral cut-off in the Fourier
domain. We derive the rate of convergence of the estimators in case of a known
and unknown error density $f_{\epsilon}$, where it is assumed that $f_X$
satisfies a polynomial, logarithmic or general source condition. It is shown
that the proposed estimators are asymptotically optimal in a minimax sense in
the models with known or unknown error density, if the density $f_X$ belongs to
a Sobolev space $H_{\mathbh p}$ and $f_{\epsilon}$ is ordinary smooth or
supersmooth.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:06:26 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Aug 2009 13:06:20 GMT"
}
] | 2009-08-21T00:00:00 | [
[
"Johannes",
"Jan",
""
]
] |
0705.3483 | Bernd Surrow | Bernd Surrow (MIT) (For the STAR Collaboration) | Recent results of the STAR high-energy polarized proton-proton program
at RHIC at BNL | 8 pages, 5 figures, Invited talk given at the 17th International Spin
Physics Symposium (SPIN 2006), October 2006, Kyoto, Japan | AIPConf.Proc.915:293-300,2007 | 10.1063/1.2750783 | null | hep-ex | null | The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at
Brookhaven National Laboratory (BNL) is carrying out a spin physics program
colliding transverse or longitudinal polarized proton beams at
$\sqrt{s}=200-500 $GeV to gain a deeper insight into the spin structure and
dynamics of the proton. These studies provide fundamental tests of Quantum
Chromodynamics (QCD).
One of the main objectives of the STAR spin physics program is the
determination of the polarized gluon distribution function through a
measurement of the longitudinal double-spin asymmetry, $A_{LL}$, for various
processes. Recent results will be shown on the measurement of $A_{LL}$ for
inclusive jet production, neutral pion production and charged pion production
at $\sqrt{s}=200 $GeV. In addition to these measurements involving longitudinal
polarized proton beams, the STAR collaboration has performed several important
measurements employing transverse polarized proton beams. New results on the
measurement of the transverse single-spin asymmetry, $A_{N}$, for forward
neutral pion production and the first measurement of $A_{N}$ for mid-rapidity
di-jet production will be discussed.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:15:48 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Surrow",
"Bernd",
"",
"MIT"
]
] |
0705.3484 | Hisham Sati | Hisham Sati | An approach to anomalies in M-theory via KSpin | 23 pages | J.Geom.Phys.58:387-401,2008 | 10.1016/j.geomphys.2007.11.010 | null | hep-th | null | The M-theory fieldstrength and its dual, given by the integral lift of the
left hand side of the equation of motion, both satisfy certain cohomological
properties. We study the combined fields and observe that the multiplicative
structure on the product of the corresponding degree four and degree eight
cohomology fits into that given by Spin K-theory. This explains some earlier
results and leads naturally to the use of Spin characteristic classes. We
reinterpret the one-loop term in terms of such classes and we show that it is
homotopy invariant. We argue that the various anomalies have natural
interpretations within Spin K-theory. In the process, mod 3 reductions play a
special role.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:54:44 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sati",
"Hisham",
""
]
] |
0705.3485 | Craig Antonio Pastro | Brian J. Day | Biclosed bicategories: localisation of convolution | 4 pages | null | null | null | math.CT math.QA | null | We give a summary (without proofs) of the main results in the author's thesis
entitled ``Construction of biclosed categories'' (University of New South
Wales, Australia, 1970). This summary is reprinted directly from Report 81-0030
of the School of Mathematics and Physics, Macquarie University, April 1981. In
particular, it gives sufficient conditions for existence of an extension of a
(pro)monoidal category structure along a given dense functor to a cocomplete
category. The two basic procedures used in the proof turn out to be special
cases of the final result, the two respective dense functors then being the
Yoneda embedding followed by a localisation. The final result has a standard
universal property based on left Kan extension of (pro)monoidal functors along
the given dense functor, however this property is not stated explicitly here.
| [
{
"version": "v1",
"created": "Wed, 23 May 2007 23:45:20 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Day",
"Brian J.",
""
]
] |
0705.3486 | K. R. Goodearl | K. R. Goodearl and S. Launois | The Dixmier-Moeglin equivalence and a Gel'fand-Kirillov problem for
Poisson polynomial algebras | null | null | null | null | math.RT math.QA math.RA | null | The structure of Poisson polynomial algebras of the type obtained as
semiclassical limits of quantized coordinate rings is investigated. Sufficient
conditions for a rational Poisson action of a torus on such an algebra to leave
only finitely many Poisson prime ideals invariant are obtained. Combined with
previous work of the first-named author, this establishes the Poisson
Dixmier-Moeglin equivalence for large classes of Poisson polynomial rings, such
as semiclassical limits of quantum matrices, quantum symplectic and euclidean
spaces, quantum symmetric and antisymmetric matrices. For a similarly large
class of Poisson polynomial rings, it is proved that the quotient field of the
algebra (respectively, of any Poisson prime factor ring) is a rational function
field $F(x_1,...,x_n)$ over the base field (respectively, over an extension
field of the base field) with $\{x_i,x_j\}= \lambda_{ij} x_ix_j$ for suitable
scalars $\lambda_{ij}$, thus establishing a quadratic Poisson version of the
Gel'fand-Kirillov problem. Finally, partial solutions to the isomorphism
problem for Poisson fields of the type just mentioned are obtained.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 00:06:23 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Goodearl",
"K. R.",
""
],
[
"Launois",
"S.",
""
]
] |
0705.3487 | Antoine Meyer | Arnaud Carayol (IRISA), Antoine Meyer (LIAFA) | Linearly bounded infinite graphs | null | Acta Informatica 43, 4 (25/08/2006) p. 265-292 | 10.1007/s00236-006-0022-z | null | cs.LO | null | Linearly bounded Turing machines have been mainly studied as acceptors for
context-sensitive languages. We define a natural class of infinite automata
representing their observable computational behavior, called linearly bounded
graphs. These automata naturally accept the same languages as the linearly
bounded machines defining them. We present some of their structural properties
as well as alternative characterizations in terms of rewriting systems and
context-sensitive transductions. Finally, we compare these graphs to rational
graphs, which are another class of automata accepting the context-sensitive
languages, and prove that in the bounded-degree case, rational graphs are a
strict sub-class of linearly bounded graphs.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 15:29:21 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Carayol",
"Arnaud",
"",
"IRISA"
],
[
"Meyer",
"Antoine",
"",
"LIAFA"
]
] |
0705.3488 | Ann Sophie Rittner | Ann Sophie C. Rittner, John D. Reppy | Annealing in solid $^4$He | 6 pages, 4 figures conference proceedings for QFS2007 (to be
published in Journal of Low Temperature Physics) | null | null | null | cond-mat.other cond-mat.stat-mech | null | We have used a torsional oscillator with square cross section and a resonance
frequency of 185 Hz to confirm the nonclassical rotational inertia (NCRI)
discovered by Kim and Chan\cite{1,2}. We have also found a strong correlation
between the NCRI signal and a high dissipation Q$^{-1}$ of 4 $\times$ 10$^{-6}$
of the oscillation above the transition temperature. Here, we present
preliminary results of the annealing process in $^{4}$He at a pressure of 26
bar. When holding the temperature constant above 1 K we have observed a
immediate rise in the period and a slow decay of the dissipation. The
equilibrium value of Q$^{-1}$ decreases with increasing temperature.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 00:23:10 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Rittner",
"Ann Sophie C.",
""
],
[
"Reppy",
"John D.",
""
]
] |
0705.3489 | Edward Tetteh-lartey | E. Tetteh-Lartey | A New Perspective to Cosmic Evolution and Vacuum Selection on a
Superspace | 7 pages, 1 figure, fixed minor typo errors, restructured and added a
bit more | null | null | null | hep-th | null | I conjecture that a flat 10D compact universe emerged out of nothing (By
``nothing'' I mean no notion of space and time) with all it's symmetries
intact: Poincare invariance, conformal invariance and supersymmetry, it's
massless moduli fields, and a zero energy density. Its subsequent evolution and
spontaneous breaking of these symmetries or by quantum fluctuations leads to
topological defects on this superspace which are the fields we observe (or
haven't yet observed) propagating in this spacetime. By the law of naturalness
it will restore all these broken symmetries. In recent years, the cosmological
constant problem has metamorphosed to a new problem of finding a selection
mechanism that selects our vacuum out of a string theory landscape or resign to
anthropic reasoning. I provide a new perspective for solving this problem using
a multistep approach based on the wavefunction, inflation and conformal
symmetry.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 19:27:13 GMT"
},
{
"version": "v2",
"created": "Thu, 24 May 2007 21:07:06 GMT"
},
{
"version": "v3",
"created": "Sun, 27 May 2007 21:47:43 GMT"
},
{
"version": "v4",
"created": "Mon, 28 May 2007 20:45:53 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Tetteh-Lartey",
"E.",
""
]
] |
0705.3490 | Ken-Ji Hamada | Ken-ji Hamada (KEK), Shinichi Horata (Sokendai), Naoshi Sugiyama
(Nagoya Univ.), Tetsuyuki Yukawa (Sokendai) | Analyzing WMAP Observation by Quantum Gravity | 12 pages, 7 figures | null | 10.1143/PTP.119.253 | null | astro-ph gr-qc hep-ph hep-th | null | The angular power spectra of cosmic microwave background are analyzed under
the light of the evolutional scenario of the universe based on the
renormalizable quantum theory of gravity in four dimensions. The equation of
evolution is solved numerically fixing the power law spectrum predicted by the
conformal gravity for the initial condition. The equation requires to introduce
a dynamical energy scale about 10^{17}GeV, where the inflationary space-time
evolution makes a transition to the big-bang of the conventional Friedmann
universe. The quality of fit to the three-year data of WMAP implies the
possibility to understand the observation by quantum gravity.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 01:00:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hamada",
"Ken-ji",
"",
"KEK"
],
[
"Horata",
"Shinichi",
"",
"Sokendai"
],
[
"Sugiyama",
"Naoshi",
"",
"Nagoya Univ."
],
[
"Yukawa",
"Tetsuyuki",
"",
"Sokendai"
]
] |
0705.3491 | Alex D. Gottlieb | Alex D. Gottlieb, Thorsten Schumm | Opposite sign correlations in fermion or boson gases | null | null | null | null | quant-ph | null | We investigate pair correlations in trapped fermion and boson gases as a
means to probe the quantum states producing the density fluctuations. We point
out that "opposite sign correlations" (meaning pair correlations that are
positive for fermions and negative for bosons) unambiguously indicate that the
quantum many-particle state cannot be "free." In particular, a system of
fermions that exhibits positive pair correlations cannot be described by any
Slater determinant wavefunction. This insight may help one to interpret results
of current experiments on ultracold atomic gases.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 01:13:23 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Gottlieb",
"Alex D.",
""
],
[
"Schumm",
"Thorsten",
""
]
] |
0705.3492 | Andr\'e Carvalho R. R. | A. R. R. Carvalho and J. J. Hope | Stabilising entanglement by quantum jump-based feedback | 5 pages, 4 figures | null | 10.1103/PhysRevA.76.010301 | null | quant-ph | null | We show that direct feedback based on quantum jump detection can be used to
generate entangled steady states. We present a strategy that is insensitive to
detection inefficiencies and robust against errors in the control Hamiltonian.
This feedback procedure is also shown to overcome spontaneous emission effects
by stabilising states with high degree of entanglement.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 01:42:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Carvalho",
"A. R. R.",
""
],
[
"Hope",
"J. J.",
""
]
] |
0705.3493 | Kochelev Nikolai Innokentevich | Dong-Pil Min and Nikolai Kochelev | Glueball-Induced Partonic Energy Loss in Quark-Gluon Plasma | 5 pages, 3 figures, version to appear in Phys.Rev.C | Phys.Rev.C77:014901,2008 | 10.1103/PhysRevC.77.014901 | null | hep-ph | null | We discuss the energy loss of energetic parton jets in quark-gluon plasma
above the deconfinement temperature $T_c$ by the interaction with scalar and
pseudoscalar glueballs. It is shown that the loss by this mechanism is quite
important and may play the important role of the observed jet-quenching.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 02:04:42 GMT"
},
{
"version": "v2",
"created": "Fri, 8 Jun 2007 12:43:56 GMT"
},
{
"version": "v3",
"created": "Fri, 20 Jul 2007 13:25:47 GMT"
},
{
"version": "v4",
"created": "Tue, 18 Dec 2007 13:28:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Min",
"Dong-Pil",
""
],
[
"Kochelev",
"Nikolai",
""
]
] |
0705.3494 | Hiroshi Umetsu | Satoshi Iso, Takeshi Morita, Hiroshi Umetsu | Fluxes of Higher-spin Currents and Hawking Radiations from Charged Black
Holes | 15 pages | Phys.Rev.D76:064015,2007 | 10.1103/PhysRevD.76.064015 | KEK-TH-1152, OIQP-07-07, YITP-07-29 | hep-th gr-qc | null | This is an extended version of the previous paper (hep-th/0701272). Quantum
fields near horizons can be described in terms of an infinite set of
two-dimensional conformal fields. We first generalize the method of Christensen
and Fulling to charged black holes to derive fluxes of energy and charge. These
fluxes can be obtained by employing a conformal field theory technique. We then
apply this technique to obtain the fluxes of higher-spin currents and show that
the thermal distribution of Hawking radiation from a charged black hole can be
completely reproduced by investigating transformation properties of the
higher-spin currents under conformal and gauge transformations.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 09:10:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Iso",
"Satoshi",
""
],
[
"Morita",
"Takeshi",
""
],
[
"Umetsu",
"Hiroshi",
""
]
] |
0705.3495 | Ilya Vitebskiy | Alex Figotin and Ilya Vitebskiy | Slow wave resonance in periodic stacks of anisotropic layers | To be submitted to Phys. Rev. E | null | 10.1103/PhysRevA.76.053839 | null | physics.optics physics.gen-ph | null | We consider transmission band edge resonance in periodic layered structures
involving birefringent layers. Previously we have shown that the presence of
birefringent layers with misaligned in-plane anisotropy can dramatically
enhance the performance of the photonic-crystal Fabry-Perot resonator. It
allows to reduce its size by an order of magnitude without compromising on its
performance. The key characteristic of the enhanced photonic-crystal cavity is
that its Bloch dispersion relation displays a degenerate photonic band edge,
rather than only regular ones. This can be realized in specially arranged
stacks of misaligned anisotropic layers. On the down side, the presence of
birefringent layers results in the Fabry-Perot resonance being coupled only
with one (elliptic) polarization component of the incident wave, while the
other polarization component is reflected back to space. In this paper we show
how a small modification of the periodic layered array can solve the above
fundamental problem and provide a perfect impedance match regardless of the
incident wave polarization, while preserving the giant transmission resonance,
characteristic of a degenerate photonic band edge. Both features are of
critical importance for a variety of practical applications, including
antennas, light amplification, optical and microwave filters, etc.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 02:07:22 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 09:27:25 GMT"
},
{
"version": "v3",
"created": "Wed, 11 Jul 2007 20:42:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Figotin",
"Alex",
""
],
[
"Vitebskiy",
"Ilya",
""
]
] |
0705.3496 | Kenji Handa | Kenji Handa | The two-parameter Poisson--Dirichlet point process | Published in at http://dx.doi.org/10.3150/08-BEJ180 the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm) | Bernoulli 2009, Vol. 15, No. 4, 1082-1116 | 10.3150/08-BEJ180 | IMS-BEJ-BEJ180 | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The two-parameter Poisson--Dirichlet distribution is a probability
distribution on the totality of positive decreasing sequences with sum 1 and
hence considered to govern masses of a random discrete distribution. A
characterization of the associated point process (that is, the random point
process obtained by regarding the masses as points in the positive real line)
is given in terms of the correlation functions. Using this, we apply the theory
of point processes to reveal the mathematical structure of the two-parameter
Poisson--Dirichlet distribution. Also, developing the Laplace transform
approach due to Pitman and Yor, we are able to extend several results
previously known for the one-parameter case. The Markov--Krein identity for the
generalized Dirichlet process is discussed from the point of view of functional
analysis based on the two-parameter Poisson--Dirichlet distribution.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 02:18:31 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Dec 2007 07:54:59 GMT"
},
{
"version": "v3",
"created": "Tue, 12 Jan 2010 09:25:53 GMT"
}
] | 2010-01-12T00:00:00 | [
[
"Handa",
"Kenji",
""
]
] |
0705.3497 | Yuichiro Manabe | Y. Manabe, A. Hosaka and H. Toki | Effect of negative energy components for two-nucleon systems in the
relativistic framework with the separable ansatz | 18 pages, 15 figures | null | null | null | nucl-th hep-ph | null | We investigate the electromagnetic properties of the deuteron such as the
charge and magnetic form factors by solving the Bethe-Salpeter equation (BSE)
with the separable ansatz. In solving the deuteron bound state solution to the
BSE, we include negative energy components of $P$-wave in addition to the
$^3S_1$ and $^3D_1$ states of positive energy, employing a rank IV separable
ansatz. We found that the inclusion of the negative energy components improves
systematically the electromagnetic properties which are not described in the
conventional non-relativistic impulse approximation.
| [
{
"version": "v1",
"created": "Thu, 24 May 2007 02:20:22 GMT"
}
] | 2007-05-25T00:00:00 | [
[
"Manabe",
"Y.",
""
],
[
"Hosaka",
"A.",
""
],
[
"Toki",
"H.",
""
]
] |
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