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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0707.2230 | Sonjoy Majumder | Gopal Dixit, H. S. Nataraj, B. K. Sahoo, R. K. Chaudhuri and Sonjoy
Majumder | Ab initio relativistic many-body calculation of hyperfine splitting of
^{113}Cd^+ | 8 pages, 1 figure | null | 10.1103/PhysRevA.77.012718 | null | physics.atom-ph physics.comp-ph | null | This work presents accurate ab initio determination of the hyperfine
splitting for the ground state and few low-lying excited states of 113Cd+;
important candidates for the frequency standard in the microwave region, using
coupled-cluster theory (CC) in the relativistic framework. The calculated
hyperfine splitting are well in agreement with recent experimental results. We
have also carried out the lifetimes of the 5p2P1=2 and 5p2P3=2 states, which
are in well agreement with recent experimental result (Moehring et al., PRA 73
023413, 2006). The roles of different electron correlation effects in the
determination of these quantities are discussed and their contributions are
presented in the CC terms.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 18:05:58 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Jul 2007 18:33:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dixit",
"Gopal",
""
],
[
"Nataraj",
"H. S.",
""
],
[
"Sahoo",
"B. K.",
""
],
[
"Chaudhuri",
"R. K.",
""
],
[
"Majumder",
"Sonjoy",
""
]
] |
0707.2231 | Yuri V. Stenkin | Yuri V. Stenkin | EAS Longitudinal Development and the Knee | Talk given at 30th ICRC, Merida, Mexico (2007) 5 pages, 3 figures | null | null | null | astro-ph | null | It is shown that Extensive Air Shower (EAS) longitudinal development has a
critical point where an equilibrium between the main hadronic component and the
secondary electromagnetic one exhibits a brake. This results in a change of
slope in quasi-power law function $N_{e}(Eo)$. The latter leads to a knee in
the EAS size spectrum at primary energy of about 100 TeV/nucleon. Many
``strange'' experimental results can be successfully explained in the frames of
current approach.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 18:35:49 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Stenkin",
"Yuri V.",
""
]
] |
0707.2232 | D. A. Glazov | A.V. Maiorova, D.A. Telnov, V.M. Shabaev, I.I. Tupitsyn, G. Plunien,
T. St\"ohlker | Backward scattering of low-energy antiprotons by highly charged and
neutral uranium: Coulomb glory | 14 pages, 5 figures | Phys. Rev. A 76, 032709 (2007) | 10.1103/PhysRevA.76.032709 | null | physics.atom-ph | null | Collisions of antiprotons with He-, Ne-, Ni-like, bare, and neutral uranium
are studied theoretically for scattering angles close to 180$^{\circ}$ and
antiproton energies with the interval 100 eV -- 10 keV. We investigate the
Coulomb glory effect which is caused by a screening of the Coulomb potential of
the nucleus and results in a prominent maximum of the differential cross
section in the backward direction at some energies of the incident particle. We
found that for larger numbers of electrons in the ion the effect becomes more
pronounced and shifts to higher energies of the antiproton. On the other hand,
a maximum of the differential cross section in the backward direction can also
be found in the scattering of antiprotons on a bare uranium nucleus. The latter
case can be regarded as a manifestation of the screening property of the
vacuum-polarization potential in non-relativistic collisions of heavy
particles.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 18:47:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Maiorova",
"A. V.",
""
],
[
"Telnov",
"D. A.",
""
],
[
"Shabaev",
"V. M.",
""
],
[
"Tupitsyn",
"I. I.",
""
],
[
"Plunien",
"G.",
""
],
[
"Stöhlker",
"T.",
""
]
] |
0707.2233 | M. N. Rebelo | M. N. Rebelo | Nondecoupling of Heavy Fermions and a Special Yukawa Texture | Invited talk at CTP Symposium on Supersymmetry at LHC: Theoretical
and Experimental Prospectives, Cairo, Egypt, 11-14 Mar 2007 | Int.J.Mod.Phys.A22:5853-5859,2007 | 10.1142/S0217751X07039079 | null | hep-ph | null | Talk based on work entitled ``Yukawa textures, new physics and
nondecoupling,'' done in collaboration with G. C. Branco and J. I.
Silva-Marcos, arXiv:hep-ph/0612252, to appear in Phys. Rev. D. In this work we
pointed out that New Physics can play an important r\^ ole in rescuing some of
the Yukawa texture zero ans\" atze which would otherwise be eliminated by the
recent, more precise measurements of $V_{CKM}$. We have shown that the presence
of an isosinglet vector-like quark which mixes with standard quarks, can render
viable a particularly interesting four texture zero Yukawa ansatz. The crucial
point is the nondecoupling of the effects of the isosinglet quark, even for
arbitrary large values of its mass.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 18:52:12 GMT"
}
] | 2010-11-03T00:00:00 | [
[
"Rebelo",
"M. N.",
""
]
] |
0707.2234 | Andy W. C. Lau | A.W.C. Lau, T.C. Lubensky | State-dependent diffusion: thermodynamic consistency and its path
integral formulation | 18 pages, 8 figures, Accepted to PRE | null | 10.1103/PhysRevE.76.011123 | null | cond-mat.soft cond-mat.stat-mech | null | The friction coefficient of a particle can depend on its position as it does
when the particle is near a wall. We formulate the dynamics of particles with
such state-dependent friction coefficients in terms of a general Langevin
equation with multiplicative noise, whose evaluation requires the introduction
of specific rules. Two common conventions, the Ito and the Stratonovich,
provide alternative rules for evaluation of the noise, but other conventions
are possible. We show the requirement that a particle's distribution function
approach the Boltzmann distribution at long times dictates that a drift term
must be added to the Langevin equation. This drift term is proportional to the
derivative of the diffusion coefficient times a factor that depends on the
convention used to define the multiplicative noise. We explore the consequences
of this result in a number examples with spatially varying diffusion
coefficients. We also derive path integral representations for arbitrary
interpretation of the noise, and use it in a perturbative study of correlations
in a simple system.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 19:00:09 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lau",
"A. W. C.",
""
],
[
"Lubensky",
"T. C.",
""
]
] |
0707.2235 | Andy W. C. Lau | Nicholas Sambelashvili, A.W.C. Lau, David Cai | Dynamics of bacterial flow: Emergence of spatiotemporal coherent
structures | 5 pages, 4 figures | Phys. Lett. A 360, 507 (2007) | 10.1016/j.physleta.2006.08.064 | null | cond-mat.soft | null | We propose a simple model of self-propelled particles to show that coherent
structures, such as jets and swirls, can arise from a plausible microscopic
mechanisms: (i) the elongated shape of the self-propelled particles with (ii)
the hardcore interactions among them. We demonstrate via computer simulation
that these coherent structures, which emerge at sufficiently high densities of
particles, have characteristics that are similar to those observed in recent
experiments in bacteria baths.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 19:03:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sambelashvili",
"Nicholas",
""
],
[
"Lau",
"A. W. C.",
""
],
[
"Cai",
"David",
""
]
] |
0707.2236 | Sherman Wang Dr. | Xing M. Wang | Probability Bracket Notation: Probability Space, Conditional Expectation
and Introductory Martingales | 37 pages, 5 figures | null | null | null | math.PR math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we continue to explore the consistence and usability of
Probability Bracket Notation (PBN) proposed in our previous articles. After a
brief review of PBN with dimensional analysis, we investigate probability
spaces in terms of PBN by introducing probability spaces associated with random
variables (R.V) or associated with stochastic processes (S.P). Next, we express
several important properties of conditional expectation (CE) and some their
proofs in PBN. Then, we introduce martingales based on sequence of R.V or based
on filtration in PBN. In the process, we see PBN can be used to investigate
some probability problems, which otherwise might need explicit usage of Measure
theory. Whenever applicable, we use dimensional analysis to validate our
formulas and use graphs for visualization of concepts in PBN. We hope this
study shows that PBN, stimulated by and adapted from Dirac notation in Quantum
Mechanics (QM), may have the potential to be a useful tool in probability
modeling, at least for those who are already familiar with Dirac notation in
QM.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 16:02:17 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Oct 2009 17:22:33 GMT"
}
] | 2009-10-15T00:00:00 | [
[
"Wang",
"Xing M.",
""
]
] |
0707.2237 | Justyn Maund | J.R. Maund (1), J.C. Wheeler (1), F. Patat (2), D. Baade (2), L. Wang
(3), P. Hoflich (4) ((1) Univ. of Texas, (2) ESO, (3) Texas A&M, (4) Florida
State) | Spectropolarimetry of the Type Ib/c SN 2005bf | 12 pages, 7 figures (3 colour), MNRAS accepted | null | 10.1111/j.1365-2966.2007.12230.x | null | astro-ph | null | We present spectropolarimetric observations of the peculiar Type Ib/c SN
2005bf, in MCG+00-27-005, from 3600-8550\AA. The SN was observed on 2005 April
30.9, 18 days after the first B-band light-curve maximum and 6 days before the
second B-band light-curve maximum. The degree of the Interstellar Polarization,
determined from depolarized emission lines in the spectrum, is found to be
large with $p_{max}(ISP)=1.6%$ and $\theta(ISP)=149$\fdg$7\pm4.0$, but this may
be an upper limit on the real value of the ISP. After ISP subtraction,
significant polarization is observed over large wavelength regions, indicating
a significant degree of global asymmetry, $\gtrsim 10%$. Polarizations of 3.5%
and 4% are observed for absorption components of Ca II H&K and IR triplet, and
1.3% for He I 5876\AA and Fe II. On the $Q-U$ plane clear velocity-dependent
loop structure is observed for the He I 5876\AA line, suggestive of departures
from an axial symmetry and possible clumping of the SN ejecta. Weak High
Velocity components of $\mathrm{H\alpha}$, $\mathrm{H\beta}$ and
$\mathrm{H\gamma}$ are observed, with velocities of -15 000\kms. The low degree
of polarization observed at H$\beta$ suggests that the polarization observed
for the other Balmer lines ($\sim 0.4%$ above the background polarization) may
rather be due to blending of $\mathrm{H\alpha}$ and $\mathrm{H\gamma}$ with
polarized Si II and Fe II lines, respectively. We suggest a model in which a
jet of material, that is rich in $\mathrm{^{56}Ni}$, has penetrated the C-O
core, but not the He mantle. The jet axis is tilted with respect to the axis of
the photosphere. This accounts for the lack of significant polarization of O I
7774\AA, the delayed excitation and, hence, observability of He I and,
potentially, the varied geometries of He and Ca.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 20:02:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Maund",
"J. R.",
""
],
[
"Wheeler",
"J. C.",
""
],
[
"Patat",
"F.",
""
],
[
"Baade",
"D.",
""
],
[
"Wang",
"L.",
""
],
[
"Hoflich",
"P.",
""
]
] |
0707.2238 | Damien Chablat | Mazen Zein (IRCCyN), Philippe Wenger (IRCCyN), Damien Chablat (IRCCyN) | A design oriented study for 3R Orthogonal Manipulators With Geometric
Simplifications | null | Congr\`es international Conception et Mod\'elisation des
Syst\`emes M\'ecaniques (03/2007) 1-8 | null | null | cs.RO | null | This paper proposes a method to calculate the largest Regular Dextrous
Workspace (RDW) of some types of three-revolute orthogonal manipulators that
have at least one of their DH parameters equal to zero. Then a new performance
index based on the RDW is introduced, the isocontours of this index are plotted
in the parameter space of the interesting types of manipulators and finally an
inspection of the domains of the parameter spaces is conducted in order to
identify the better manipulator architectures. The RDW is a part of the
workspace whose shape is regular (cube, cylinder) and the performances
(conditioning index) are bounded inside. The groups of 3R orthogonal
manipulators studied have interesting kinematic properties such as, a
well-connected workspace that is fully reachable with four inverse kinematic
solutions and that does not contain any void. This study is of high interest
for the design of alternative manipulator geometries.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 20:25:24 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Zein",
"Mazen",
"",
"IRCCyN"
],
[
"Wenger",
"Philippe",
"",
"IRCCyN"
],
[
"Chablat",
"Damien",
"",
"IRCCyN"
]
] |
0707.2239 | James Storey | J.G. Storey, J.L. Tallon, G.V.M. Williams | Saddle-point van Hove singularity and the phase diagram of high-Tc
cuprates | 5 pages, 2 figures, submitted to Physical Review B | null | 10.1103/PhysRevB.76.174522 | null | cond-mat.supr-con | null | We examine the generic phase behavior of high-Tc cuprate superconductors in
terms a universal van Hove singularity in the strongly overdoped region. Using
a rigid ARPES-derived dispersion we solve the BCS gap equation and show that
the pairing interaction or pairing energy cutoff must be a rapidly declining
function of doping. This result is prejudicial to a phonon-based pairing
interaction and more consistent with a magnetic or magnetically enhanced
interaction.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 20:52:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Storey",
"J. G.",
""
],
[
"Tallon",
"J. L.",
""
],
[
"Williams",
"G. V. M.",
""
]
] |
0707.2240 | Chang Liu | Chang Liu, Jeongwoo Lee, Vasyl Yurchyshyn, Na Deng, Kyung-Suk Cho,
Marian Karlicky, and Haimin Wang | The Eruption from a Sigmoidal Solar Active Region on 2005 May 13 | 10 pages, 10 figures, The Astrophysical Journal, accepted July, 2007 | null | 10.1086/521644 | null | astro-ph | null | This paper presents a multiwavelength study of the M8.0 flare and its
associated fast halo CME that originated from a bipolar active region NOAA
10759 on 2005 May 13. The source active region has a conspicuous sigmoid
structure at TRACE 171 A channel as well as in the SXI soft X-ray images, and
we mainly concern ourselves with the detailed process of the sigmoid eruption
as evidenced by the multiwavelength data ranging from Halpha, WL, EUV/UV,
radio, and hard X-rays (HXRs). The most important finding is that the flare
brightening starts in the core of the active region earlier than that of the
rising motion of the flux rope. This timing clearly addresses one of the main
issues in the magnetic eruption onset of sigmoid, namely, whether the eruption
is initiated by an internal tether-cutting to allow the flux rope to rise
upward or a flux rope rises due to a loss of equilibrium to later induce tether
cutting below it. Our high time cadence SXI and Halpha data shows that the
first scenario is relevant to this eruption. As other major findings, we have
the RHESSI HXR images showing a change of the HXR source from a confined
footpoint structure to an elongated ribbon-like structure after the flare
maximum, which we relate to the sigmoid-to-arcade evolution. Radio dynamic
spectrum shows a type II precursor that occurred at the time of expansion of
the sigmoid and a drifting pulsating structure in the flare rising phase in
HXR. Finally type II and III bursts are seen at the time of maximum HXR
emission, simultaneous with the maximum reconnection rate derived from the
flare ribbon motion in UV. We interpret these various observed properties with
the runaway tether-cutting model proposed by Moore et al. in 2001.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 21:23:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Liu",
"Chang",
""
],
[
"Lee",
"Jeongwoo",
""
],
[
"Yurchyshyn",
"Vasyl",
""
],
[
"Deng",
"Na",
""
],
[
"Cho",
"Kyung-Suk",
""
],
[
"Karlicky",
"Marian",
""
],
[
"Wang",
"Haimin",
""
]
] |
0707.2241 | Lesfari Ahmed | A. Lesfari | Etude Des Solutions Meromorphes D'Equations Differentielles | 21 pages | null | null | null | math.CA math-ph math.MP | null | In this paper we shall study differential equations in the complex domain.
The method of indeterminate coefficients and the majorant method lead to a
proof of the existence and uniqueness of meromorphic solution of differential
equations. We discuss their connection with the concept of algebraic
integrability systems.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 22:02:04 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Lesfari",
"A.",
""
]
] |
0707.2242 | Debdeep Jena | Tian Fang, Aniruddha Konar, Huili Xing, Debdeep Jena | Carrier Statistics and Quantum Capacitance of Graphene Sheets and
Ribbons | 3 pages, 3 figures, submitted to Applied Physics Letters | null | 10.1063/1.2776887 | null | cond-mat.mtrl-sci | null | In this work, fundamental results for carrier statistics in graphene
2-dimensional sheets and nanoscale ribbons are derived. Though the behavior of
intrinsic carrier densities in 2d graphene sheets is found to differ
drastically from traditional semiconductors, very narrow (sub-10 nm) ribbons
are found to be similar to traditional narrow-gap semiconductors. The quantum
capacitance, an important parameter in the electrostatic design of devices, is
derived for both 2d graphene sheets and nanoribbons.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 22:33:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fang",
"Tian",
""
],
[
"Konar",
"Aniruddha",
""
],
[
"Xing",
"Huili",
""
],
[
"Jena",
"Debdeep",
""
]
] |
0707.2243 | Lauro Tomio | F.Kh. Abdullaev, A. Gammal, H.L.F. da Luz, and Lauro Tomio | Dissipative Dynamics of Matter Wave Soliton in Nonlinear Optical Lattice | 9 pages, 8 figures | null | 10.1103/PhysRevA.76.043611 | null | cond-mat.other | null | Dynamics and stability of solitons in two-dimensional (2D) Bose-Einstein
condensates (BEC), with low-dimensional (1D) conservative plus dissipative
nonlinear optical lattices are investigated. In the case of focusing media
(with attractive atomic systems) the collapse of the wave packet is arrested by
the dissipative periodic nonlinearity. The adiabatic variation of the
background scattering length leads to metastable matter-wave solitons.
When the atom feeding mechanism is used, a dissipative soliton can exist in
focusing 2D media with 1D periodic nonlinearity. In the defocusing media
(repulsive BEC case) with harmonic trap in one dimension and one dimensional
nonlinear optical lattice in other direction, the stable soliton can exist.
This prediction of variational approach is confirmed by the full numerical
simulation of 2D Gross-Pitaevskii equation.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 22:42:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Abdullaev",
"F. Kh.",
""
],
[
"Gammal",
"A.",
""
],
[
"da Luz",
"H. L. F.",
""
],
[
"Tomio",
"Lauro",
""
]
] |
0707.2244 | Debdeep Jena | Debdeep Jena, and Aniruddha Konar | Enhancement of Carrier Mobility in Semiconductor Nanostructures by
Dielectric Engineering | 5 Pages, 4 Figures | Physical Review Letters, 98, 136805, 2007 | 10.1103/PhysRevLett.98.136805 | null | cond-mat.mtrl-sci | null | We propose a technique for achieving large improvements in carrier mobilities
in 2- and 1-dimensional semiconductor nanostructures by modifying their
dielectric environments. We show that by coating the nanostructures with
high-$\kappa$ dielectrics, scattering from Coulombic impurities can be strongly
damped. Though screening is also weakened, the damping of Coulombic scattering
is much larger, and the resulting improvement in mobilities of carriers can be
as much as an order of magnitude for thin 2D semiconductor membranes, and more
for semiconductor nanowires.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 23:00:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jena",
"Debdeep",
""
],
[
"Konar",
"Aniruddha",
""
]
] |
0707.2245 | Ioan Valeriu Grossu | I. V. Grossu, C. Besliu, Al. Jipa, D. Felea, C. C. Bordeianu | Some phenomenological considerations on the nuclear collisions at high
energies | 7 pages, 2 figures, preliminary results presented at Conference of
Physics, Bucharest, 2007 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present some results obtained by applying the chaos theory on the
numerical study of one threedimensional, relativistic, many-body quark system.
The asymptotic freedom property is introduced by employing a harmonic term in
the bi-particle potential. In this context, we used also the outcome of a
semiclassical study, applied to the quark constituents of nucleons. Depending
on the initial temperature parameter, the system can evolve toward an
oscillating or an expansion regime. It is important to notice also a transition
region, characterized by a partial fragmentation (higher degree of order). This
effect can be observed near the critical temperature and is related to the
partial overcoming of the potential barrier (corresponding to the farthest
particles from the system). The degree of fragmentation is defined on the
Shannon entropy basis and using the graphs theory. For analyzing the expansion
tendency of one relativistic many-body system, we employed also the virial
coefficient.
| [
{
"version": "v1",
"created": "Sun, 15 Jul 2007 23:07:38 GMT"
},
{
"version": "v2",
"created": "Tue, 20 Nov 2007 09:21:26 GMT"
},
{
"version": "v3",
"created": "Wed, 26 Mar 2008 18:44:39 GMT"
},
{
"version": "v4",
"created": "Sun, 15 Feb 2009 22:01:04 GMT"
},
{
"version": "v5",
"created": "Mon, 6 Jul 2009 22:04:08 GMT"
}
] | 2009-07-07T00:00:00 | [
[
"Grossu",
"I. V.",
""
],
[
"Besliu",
"C.",
""
],
[
"Jipa",
"Al.",
""
],
[
"Felea",
"D.",
""
],
[
"Bordeianu",
"C. C.",
""
]
] |
0707.2246 | Aleks Kleyn | Aleks Kleyn | Fibered Correspondence | English text - 19 pages; Russian text - 21 pages | null | null | null | math.DG math.AT | null | Base of fibered correspondence is arbitrary correspondence. Fibered
correspondence is interesting when we consider relationship between different
bundles. However composition of fibered correspondences may not always be
defined. Reduced fibered correspondence is defined only between fibers over the
same point of base. Reduced fibered correspondence in bundle is called 2-ary
fibered relation. We considered fibered equivalence and isomorphism theorem in
case of fibered morphisms.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 02:33:26 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Dec 2007 06:14:30 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Kleyn",
"Aleks",
""
]
] |
0707.2247 | Akihito Wachi | Tadahito Harima and Akihito Wachi | Generic initial ideals, graded Betti numbers and $k$-Lefschetz
properties | 36 pages; a refererence [CP07] added | null | null | null | math.AC | null | We introduce the $k$-strong Lefschetz property ($k$-SLP) and the $k$-weak
Lefschetz property ($k$-WLP) for graded Artinian $K$-algebras, which are
generalizations of the Lefschetz properties. The main results obtained in this
paper are as follows:
1. Let $I$ be a graded ideal of $R=K[x_1, x_2, x_3]$ whose quotient ring
$R/I$ has the SLP. Then the generic initial ideal of $I$ is the unique almost
revlex ideal with the same Hilbert function as $R/I$.
2. Let $I$ be a graded ideal of $R=K[x_1, x_2, ..., x_n]$ whose quotient ring
$R/I$ has the $n$-SLP. Suppose that all $k$-th differences of the Hilbert
function of $R/I$ are quasi-symmetric. Then the generic initial ideal of $I$ is
the unique almost revlex ideal with the same Hilbert function as $R/I$.
3. We give a sharp upper bound on the graded Betti numbers of Artinian
$K$-algebras with the $k$-WLP and a fixed Hilbert function.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 00:21:30 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 05:44:02 GMT"
}
] | 2007-07-19T00:00:00 | [
[
"Harima",
"Tadahito",
""
],
[
"Wachi",
"Akihito",
""
]
] |
0707.2248 | Joel Kamnitzer | Joel Kamnitzer, Peter Tingley | The crystal commutor and Drinfeld's unitarized R-matrix | 15 pages | null | null | AIM 2007 - 36 | math.QA math.CO | null | Drinfeld defined a unitarized R-matrix for any quantum group U_q(g). This
gives a commutor for the category of U_q(g) representations, making it into a
coboundary category. Henriques and Kamnitzer defined another commutor which
also gives U_q(g) representations the structure of a coboundary category. We
show that a particular case of Henriques and Kamnitzer's construction agrees
with Drinfeld's commutor. We then describe the action of Drinfeld's commutor on
a tensor product of two crystal bases, and explain the relation to the crystal
commutor.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 00:30:14 GMT"
},
{
"version": "v2",
"created": "Sun, 30 Mar 2008 06:23:11 GMT"
}
] | 2008-03-30T00:00:00 | [
[
"Kamnitzer",
"Joel",
""
],
[
"Tingley",
"Peter",
""
]
] |
0707.2249 | Satoshi Miyazaki | Satoshi Miyazaki (1), Takashi Hamana (1), Richard S. Ellis (2),
Nobunari Kashikawa (1), Richard J. Massey (2), James Taylor (3), Alexandre
Refregier (4) ((1) National Astronomical Observatory of Japan, (2) Caltech,
(3) University of Waterloo, (4) CEA/Saclay) | A Subaru Weak Lensing Survey I: Cluster Candidates and Spectroscopic
Verification | To appear in ApJ, High resolution preprint available at
http://anela.mtk.nao.ac.jp/suprime33/papers/p1.ps.gz | null | 10.1086/521621 | null | astro-ph | null | We present the results of an ongoing weak lensing survey conducted with the
Subaru telescope whose initial goal is to locate and study the distribution of
shear-selected structures or halos. Using a Suprime-cam imaging survey spanning
21.82 square degree, we present a catalog of 100 candidate halos located from
lensing convergence maps. Our sample is reliably drawn from that subset of our
survey area, (totaling 16.72 square degree) uncontaminated by bright stars and
edge effects and limited at a convergence signal to noise ratio of 3.69. To
validate the sample detailed spectroscopic measures have been made for 26
candidates using the Subaru multi-object spectrograph, FOCAS. All are confirmed
as clusters of galaxies but two arise as the superposition of multiple clusters
viewed along the line of sight. Including data available in the literature and
an ongoing Keck spectroscopic campaign, a total of 41 halos now have reliable
redshifts. For one of our survey fields, the XMM LSS (Pierre et al. 2004)
field, we compare our lensing-selected halo catalog with its X-ray equivalent.
Of 15 halos detected in the XMM-LSS field, 10 match with published X-ray
selected clusters and a further 2 are newly-detected and spectroscopically
confirmed in this work. Although three halos have not yet been confirmed, the
high success rate within the XMM-LSS field (12/15) confirms that weak lensing
provides a reliable method for constructing cluster catalogs, irrespective of
the nature of the constituent galaxies or the intracluster medium.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 00:47:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Miyazaki",
"Satoshi",
""
],
[
"Hamana",
"Takashi",
""
],
[
"Ellis",
"Richard S.",
""
],
[
"Kashikawa",
"Nobunari",
""
],
[
"Massey",
"Richard J.",
""
],
[
"Taylor",
"James",
""
],
[
"Refregier",
"Alexandre",
""
]
] |
0707.2250 | Yanxia Zhang | Dan Wang, Yan-Xia Zhang, Chao Liu and Yong-Heng Zhao | Two novel approaches for photometric redshift estimation based on SDSS
and 2MASS databases | accepted for publication in ChJAA | null | 10.1088/1009-9271/8/1/13 | null | astro-ph | null | We investigate two training-set methods: support vector machines (SVMs) and
Kernel Regression (KR) for photometric redshift estimation with the data from
the Sloan Digital Sky Survey Data Release 5 and Two Micron All Sky Survey
databases. We probe the performances of SVMs and KR for different input
patterns. Our experiments show that the more parameters considered, the
accuracy doesn't always increase, and only when appropriate parameters chosen,
the accuracy can improve. Moreover for different approaches, the best input
pattern is different. With different parameters as input, the optimal bandwidth
is dissimilar for KR. The rms errors of photometric redshifts based on SVM and
KR methods are less than 0.03 and 0.02, respectively. Finally the strengths and
weaknesses of the two approaches are summarized. Compared to other methods of
estimating photometric redshifts, they show their superiorities, especially KR,
in terms of accuracy.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 01:14:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wang",
"Dan",
""
],
[
"Zhang",
"Yan-Xia",
""
],
[
"Liu",
"Chao",
""
],
[
"Zhao",
"Yong-Heng",
""
]
] |
0707.2251 | Ewelina Hankiewicz | E. M. Hankiewicz and G. Vignale | "Phase Diagram" of the Spin Hall Effect | Some typos corrected | Phys. Rev. Lett. 100, 026602 (2008) | 10.1103/PhysRevLett.100.026602 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | We obtain analytic formulas for the frequency-dependent spin-Hall
conductivity of a two-dimensional electron gas (2DEG) in the presence of
impurities, linear spin-orbit Rashba interaction, and external magnetic field
perpendicular to the 2DEG. We show how different mechanisms (skew-scattering,
side-jump, and spin precession) can be brought in or out of focus by changing
controllable parameters such as frequency, magnetic field, and temperature. We
find, in particular, that the d.c. spin Hall conductivity vanishes in the
absence of a magnetic field, while a magnetic field restores the
skew-scattering and side-jump contributions proportionally to the ratio of
magnetic and Rashba fields.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 01:35:59 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Jul 2007 17:33:26 GMT"
},
{
"version": "v3",
"created": "Mon, 30 Jul 2007 21:54:35 GMT"
},
{
"version": "v4",
"created": "Thu, 9 Aug 2007 19:11:26 GMT"
},
{
"version": "v5",
"created": "Tue, 4 Sep 2007 16:09:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hankiewicz",
"E. M.",
""
],
[
"Vignale",
"G.",
""
]
] |
0707.2252 | Bruce Elmegreen | Bruce G. Elmegreen (IBM T.J. Watson Research Center) | On the Rapid Collapse and Evolution of Molecular Clouds | 46 pages, 5 figures, scheduled for ApJ 668, October 20, 2007 | null | 10.1086/521327 | null | astro-ph | null | Stars generally form faster than the ambipolar diffusion time, suggesting
that several processes short circuit the delay and promote a rapid collapse.
These processes are considered here, including turbulence compression in the
outer parts of giant molecular cloud (GMC) cores and GMC envelopes, GMC core
formation in an initially supercritical state, and compression-induced
triggering in dispersing GMC envelopes. The classical issues related to star
formation timescales are addressed: high molecular fractions, low efficiencies,
long consumption times for CO and HCN, rapid GMC core disruption and the lack
of a stable core, long absolute but short relative timescales with accelerated
star formation, and the slow motions of protostars. We consider stimuli to
collapse from changes in the density dependence of the ionization fraction, the
cosmic ray ionization rate, and various dust properties at densities above
~10^5 cm^{-3}. We favor the standard model of subcritical GMC envelops and
suggest they would be long lived if not for disruption by rapid star formation
in GMC cores. The lifecycle of GMCs is illustrated by a spiral arm section in
the Hubble Heritage image of M51, showing GMC formation, star formation, GMC
disruption with lingering triggered star formation, and envelope dispersal.
There is no delay between spiral arm dustlanes and star formation; the
classical notion results from heavy extinction in the dust lane and triggered
star formation during cloud dispersal. Differences in the IMF for the different
modes of star formation are considered.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 01:55:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Elmegreen",
"Bruce G.",
"",
"IBM T.J. Watson Research Center"
]
] |
0707.2253 | Robert J. McQueeney | R. J. McQueeney, M. Yethiraj, S. Chang, W. Montfrooij, T. G. Perring,
J. Honig, P. Metcalf | Zener double exchange from local valence fluctuations in magnetite | 4 pages, 5 figures | null | 10.1103/PhysRevLett.99.246401 | null | cond-mat.str-el | null | Magnetite (Fe$_{3}$O$_{4}$) is a mixed valent system where electronic
conductivity occurs on the B-site (octahedral) iron sublattice of the spinel
structure. Below $T_{V}=122$ K, a metal-insulator transition occurs which is
argued to arise from the charge ordering of 2+ and 3+ iron valences on the
B-sites (Verwey transition). Inelastic neutron scattering measurements show
that optical spin waves propagating on the B-site sublattice ($\sim$80 meV) are
shifted upwards in energy above $T_{V}$ due to the occurrence of B-B
ferromagnetic double exchange in the mixed valent metallic phase. The double
exchange interaction affects only spin waves of $\Delta_{5}$ symmetry, not all
modes, indicating that valence fluctuations are slow and the double exchange is
constrained by electron correlations above $T_{V}$.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 03:00:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"McQueeney",
"R. J.",
""
],
[
"Yethiraj",
"M.",
""
],
[
"Chang",
"S.",
""
],
[
"Montfrooij",
"W.",
""
],
[
"Perring",
"T. G.",
""
],
[
"Honig",
"J.",
""
],
[
"Metcalf",
"P.",
""
]
] |
0707.2254 | Yi Ming | Yi Ming, Zhexian Wang, Qiang Li and Zejun Ding | Nonlinear Thermal Properties of Three-Terminal Mesoscopic Dielectric
Systems | 9 pages, 3 figures | APPLIED PHYSICS LETTERS 91, 143508 (2007) | 10.1063/1.2794799 | null | cond-mat.mes-hall | null | This paper studies the thermal properties of three-terminal mesoscopic
dielectric systems in the nonlinear response regime at low temperature. For a
symmetric three-terminal system, when the temperature is finitely different
between the left and right thermal reservoirs, the temperature of the central
thermal reservoir is always higher than the averaging temperature of the
others. This nonlinear thermal phenomenon is also observed for asymmetric
three-terminal systems. At the end, a model of thermal rectification is
presented.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 02:29:48 GMT"
},
{
"version": "v2",
"created": "Thu, 4 Oct 2007 01:13:33 GMT"
}
] | 2007-10-04T00:00:00 | [
[
"Ming",
"Yi",
""
],
[
"Wang",
"Zhexian",
""
],
[
"Li",
"Qiang",
""
],
[
"Ding",
"Zejun",
""
]
] |
0707.2255 | Takami Kuroda | Takami Kuroda, Shinya Wanajo, Ken'ichi Nomoto | The r-Process in Supersonic Neutrino-Driven Winds: The Roll of Wind
Termination Shock | 11 pages, 7 figures, submitted to ApJ, revised following referee's
comments,Accepted for publication in ApJ | AIP Conf.Proc.1016:436-438,2008 | 10.1063/1.2943617 | null | astro-ph | null | Recent hydrodynamic studies of core-collapse supernovae imply that the
neutrino-heated ejecta from a nascent neutron star develops to supersonic
outflows. These supersonic winds are influenced by the reverse shock from the
preceding supernova ejecta, forming the wind termination shock. We investigate
the effects of the termination shock in neutrino-driven winds and its roll on
the r-process. Supersonic outflows are calculated with a semi-analytic
neutrino-driven wind model. Subsequent termination-shocked, subsonic outflows
are obtained by applying the Rankine-Hugoniot relations. We find a couple of
effects that can be relevant for the r-process. First is the sudden slowdown of
the temperature decrease by the wind termination. Second is the entropy jump by
termination-shock heating, up to several 100NAk. Nucleosynthesis calculations
in the obtained winds are performed to examine these effects on the r-process.
We find that 1) the slowdown of the temperature decrease plays a decisive roll
to determine the r-process abundance curves. This is due to the strong
dependences of the nucleosynthetic path on the temperature during the r-process
freezeout phase. Our results suggest that only the termination-shocked winds
with relatively small shock radii (~500km) are relevant for the bulk of the
solar r-process abundances (A~100-180). The heaviest part in the solar
r-process curve (A~180-200), however, can be reproduced both in shocked and
unshocked winds. These results may help to constrain the mass range of
supernova progenitors relevant for the r-process. We find, on the other hand,
2) negligible roles of the entropy jump on the r-process. This is a consequence
that the sizable entropy increase takes place only at a large shock radius
(~10,000km) where the r-process has already ceased.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 03:10:59 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Sep 2007 00:18:20 GMT"
},
{
"version": "v3",
"created": "Mon, 17 Sep 2007 21:49:49 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kuroda",
"Takami",
""
],
[
"Wanajo",
"Shinya",
""
],
[
"Nomoto",
"Ken'ichi",
""
]
] |
0707.2256 | Eduard Alexis Larranaga Rubio | Alexis Larranaga | On the First Law of Thermodynamics for (2+1) Dimensional Charged BTZ
Black Hole and Charged de Sitter Space | 4 pages | Turk. J. Phys. 32, 1 (2008) | null | null | gr-qc | null | In this paper we will show that using the cosmological constant as a new
thermodynamical state variable, the differential and integral mass formulas of
the first law of thermodynamics for asymptotic flat spacetimes can be extended
to (2+1) dimensional charged BTZ black holes and charged de Sitter space.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 02:52:17 GMT"
}
] | 2008-03-06T00:00:00 | [
[
"Larranaga",
"Alexis",
""
]
] |
0707.2257 | Man-Wai Ho | Man-Wai Ho | A Bayes method for a Bathtub Failure Rate via two $\mathbf{S}$-paths | 30 pages, 5 figures | null | null | null | stat.ME | null | A class of semi-parametric hazard/failure rates with a bathtub shape is of
interest. It does not only provide a great deal of flexibility over existing
parametric methods in the modeling aspect but also results in a closed and
tractable Bayes estimator for the bathtub-shaped failure rate (BFR). Such an
estimator is derived to be a finite sum over two $\mathbf{S}$-paths due to an
explicit posterior analysis in terms of two (conditionally independent)
$\mathbf{S}$-paths. These, newly discovered, explicit results can be proved to
be a Rao-Blackwellization of counterpart results in terms of partitions that
are readily available by a specialization of James (2005)'s work. We develop
both iterative and non-iterative computational procedures based on existing
efficient Monte Carlo methods for sampling one single $\mathbf{S}$-path.
Nmerical simulations are given to demonstrate the practicality and the
effectiveness of our methodology. Last but not least, two applications of the
proposed method are discussed, of which one is about a Bayesian test for
failure rates and the other is related to modeling with covariates.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 03:37:39 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Ho",
"Man-Wai",
""
]
] |
0707.2258 | Jie Jiang | Jie Jiang, Piyali Chatterjee, and Arnab Rai Choudhuri | Solar activity forecast with a dynamo model | 17 pages, 18 figures, submitted to MNRAS | null | 10.1111/j.1365-2966.2007.12267.x | null | astro-ph | null | Although systematic measurements of the solar polar magnetic field exist only
from mid 1970s, other proxies can be used to infer the polar field at earlier
times. The observational data indicate a strong correlation between the polar
field at a sunspot minimum and the strength of the next cycle, although the
strength of the cycle is not correlated well with the polar field produced at
its end. This suggests that the Babcock Leighton mechanism of poloidal field
generation from decaying sunspots involves randomness, whereas the other
aspects of the dynamo process must be reasonably ordered and deterministic.
Only if the magnetic diffusivity within the convection zone is assumed to be
high, we can explain the correlation between the polar field at a minimum and
the next cycle. We give several independent arguments that the diffusivity must
be of this order. In a dynamo model with diffusivity like this, the poloidal
field generated at the mid latitudes is advected toward the poles by the
meridional circulation and simultaneously diffuses towards the tachocline,
where the toroidal field for the next cycle is produced. To model actual solar
cycles with a dynamo model having such high diffusivity, we have to feed the
observational data of the poloidal field at the minimum into the theoretical
model. We develop a method of doing this in a systematic way. Our model
predicts that cycle 24 will be a very weak cycle. Hemispheric asymmetry of
solar activity is also calculated with our model and compared with
observational data.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 04:09:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jiang",
"Jie",
""
],
[
"Chatterjee",
"Piyali",
""
],
[
"Choudhuri",
"Arnab Rai",
""
]
] |
0707.2259 | Vladimir Nikiforov | Vladimir Nikiforov | A spectral Erdos-Stone-Bollobas theorem | Some polishing. Updated refrences | null | null | null | math.CO | null | We give a bound on the spectral radius of a graph implying a quantitative
version of the Erdos-Stone theorem.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 05:17:45 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 20:31:58 GMT"
},
{
"version": "v3",
"created": "Thu, 22 Nov 2007 00:14:20 GMT"
}
] | 2007-11-22T00:00:00 | [
[
"Nikiforov",
"Vladimir",
""
]
] |
0707.2260 | Michael M. Wolf | David Perez-Garcia, Frank Verstraete, J. Ignacio Cirac, Michael M.
Wolf | PEPS as unique ground states of local Hamiltonians | 8 pages | Quant. Inf. Comp. 8, 0650-0663 (2008). | null | null | quant-ph cond-mat.stat-mech math-ph math.MP | null | In this paper we consider projected entangled pair states (PEPS) on arbitrary
lattices. We construct local parent Hamiltonians for each PEPS and isolate a
condition under which the state is the unique ground state of the Hamiltonian.
This condition, verified by generic PEPS and examples like the AKLT model, is
an injective relation between the boundary and the bulk of any local region.
While it implies the existence of an energy gap in the 1D case we will show
that in certain cases (e.g., on a 2D hexagonal lattice) the parent Hamiltonian
can be gapless with a critical ground state. To show this we invoke a mapping
between classical and quantum models and prove that in these cases the
injectivity relation between boundary and bulk solely depends on the lattice
geometry.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 05:21:57 GMT"
}
] | 2008-06-27T00:00:00 | [
[
"Perez-Garcia",
"David",
""
],
[
"Verstraete",
"Frank",
""
],
[
"Cirac",
"J. Ignacio",
""
],
[
"Wolf",
"Michael M.",
""
]
] |
0707.2261 | Michael Gillon | M. Gillon (1, 2), B.-O. Demory (1), T. Barman (3), X. Bonfils (4), T.
Mazeh (5), F. Pont (1), S. Udry (1), M. Mayor (1), D. Queloz (1) ((1)
Observatoire de l'Universite de Geneve, Sauverny, Switzerland, (2) Institut
d'Astrophysique et de Geophysique, Universite de Liege, Liege, Belgium, (3)
Lowell Observatory, Flagstaff, USA, (4) Observatorio Astronomico de Lisboa,
Lisboa, Portugal, (5) School of Physics and Astronomy, Raymond and Beverly
Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel) | Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b | Accepted for publication in A&A on 21/07/2007; 5 pages, 3 figures | null | 10.1051/0004-6361:20078283 | null | astro-ph | null | We present Spitzer Space Telescope infrared photometry of a primary transit
of the hot Neptune GJ 436b. The observations were obtained using the 8 microns
band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data
and the weak limb-darkening in the 8 microns IRAC band allow us to derive
(assuming M = 0.44 +- 0.04 Msun for the primary) a precise value for the
planetary radius (4.19 +0.21-0.16 Rearth), the stellar radius (0.463
+0.022-0.017 Rsun), the orbital inclination (85.90 +0.19-0.18 degrees) and
transit timing (2454280.78186 +0.00015-0.00008 HJD). Assuming current planet
models, an internal structure similar to that of Neptune with a small H/He
envelope is necessary to account for the measured radius of GJ 436b.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:27:36 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Jul 2007 15:43:31 GMT"
},
{
"version": "v3",
"created": "Fri, 20 Jul 2007 06:04:52 GMT"
},
{
"version": "v4",
"created": "Tue, 24 Jul 2007 01:36:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gillon",
"M.",
""
],
[
"Demory",
"B. -O.",
""
],
[
"Barman",
"T.",
""
],
[
"Bonfils",
"X.",
""
],
[
"Mazeh",
"T.",
""
],
[
"Pont",
"F.",
""
],
[
"Udry",
"S.",
""
],
[
"Mayor",
"M.",
""
],
[
"Queloz",
"D.",
""
]
] |
0707.2262 | Andrew Putman | Nathan Broaddus, Benson Farb, Andrew Putman | Irreducible Sp-representations and subgroup distortion in the mapping
class group | 17 pages; fixed TeX errors in arXiv title and abstract, paper
unchanged | Comment. Math. Helv. 86 (2011), 537-556 | 10.4171/CMH/233 | null | math.GT math.GR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We prove that various subgroups of the mapping class group $Mod(\Sigma)$ of a
surface $\Sigma$ are at least exponentially distorted. Examples include the
Torelli group (answering a question of Hamenstadt), the "point-pushing" and
surface braid subgroups, and the Lagrangian subgroup. Our techniques include a
method to compute lower bounds on distortion via representation theory and an
extension of Johnson theory to arbitrary subgroups of $H_1(\Sigma;\mathbb{Z})$.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 06:02:29 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Jan 2009 21:32:34 GMT"
},
{
"version": "v3",
"created": "Tue, 2 Jun 2009 02:17:09 GMT"
},
{
"version": "v4",
"created": "Mon, 8 Jun 2020 21:24:38 GMT"
}
] | 2020-06-11T00:00:00 | [
[
"Broaddus",
"Nathan",
""
],
[
"Farb",
"Benson",
""
],
[
"Putman",
"Andrew",
""
]
] |
0707.2263 | Kyrill Bugaev | K. A. Bugaev | The Role of Surface Tension for the Equation of State of Quark-Gluon
Bags | Talk given at the School-seminar `New Physics and Quantum
Chromodynamics at External Conditions', Dnieproperovsk, Ukraine, May 3-6,
2007. Typos corrected | null | null | null | nucl-th | null | The temperature and chemical potential dependent surface tension of bags is
introduced into the gas of quark-gluon bags model. The suggested model is
solved analytically. It resolves a long standing problem of a unified
description of the first and second order phase transition with the cross-over.
Such an approach is necessary to model the complicated properties of
quark-gluon plasma and hadronic matter from the first principles of statistical
mechanics. In addition to the deconfinement phase transition, we found that at
the curve of a zero surface tension coefficient there must exist the surface
induced phase tranition of the 2-nd or higher order, which separates the pure
quark gluon plasma (QGP) from the cross-over states. Thus, the present model
predicts that the critical endpoint of quantum chromodynamics is the
tricritical endpoint.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:42:31 GMT"
},
{
"version": "v2",
"created": "Tue, 20 Nov 2007 16:48:56 GMT"
}
] | 2007-11-20T00:00:00 | [
[
"Bugaev",
"K. A.",
""
]
] |
0707.2264 | Andrew Putman | Nathan Broaddus, Benson Farb, Andrew Putman | The Casson invariant and the word metric on the Torelli group | 5 pages, minor corrections; to appear in C. R. Math. Acad. Sci. Paris | C. R. Acad. Sci. Paris, Ser. I 345 (2007) 449--452 | 10.1016/j.crma.2007.09.018 | null | math.GT math.GR | null | We bound the value of the Casson invariant of any integral homology 3-sphere
$M$ by a constant times the distance-squared to the identity, measured in any
word metric on the Torelli group $\T$, of the element of $\T$ associated to any
Heegaard splitting of $M$. We construct examples which show this bound is
asymptotically sharp.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 06:09:19 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Sep 2007 21:29:18 GMT"
}
] | 2020-06-08T00:00:00 | [
[
"Broaddus",
"Nathan",
""
],
[
"Farb",
"Benson",
""
],
[
"Putman",
"Andrew",
""
]
] |
0707.2265 | Rajesh Sundaresan | Arun Padakandla and Rajesh Sundaresan | Separable convex optimization problems with linear ascending constraints | 15 pages, Submitted to SIAM J. on Opt | SIAM J. on Optim., vol. 20, no. 3, pp. 1185-1204, online version
19 August 2009 | 10.1137/07069729X | null | cs.IT math.IT math.OC | null | Separable convex optimization problems with linear ascending inequality and
equality constraints are addressed in this paper. Under an ordering condition
on the slopes of the functions at the origin, an algorithm that determines the
optimum point in a finite number of steps is described. The optimum value is
shown to be monotone with respect to a partial order on the constraint
parameters. Moreover, the optimum value is convex with respect to these
parameters. Examples motivated by optimizations for communication systems are
used to illustrate the algorithm.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 06:23:38 GMT"
}
] | 2011-07-22T00:00:00 | [
[
"Padakandla",
"Arun",
""
],
[
"Sundaresan",
"Rajesh",
""
]
] |
0707.2266 | Yoav Tsori | Yoav Tsori and Ludwik Leibler | Phase-separation of miscible liquids in a centrifuge | 6 pages, 3 figures | Comptes Rendus Physique, vol 8, 955 (2007) | 10.1016/j.crhy.2007.09.017 | null | cond-mat.soft cond-mat.stat-mech | null | We show that a liquid mixture in the thermodynamically stable homogeneous
phase can undergo a phase-separation transition when rotated at sufficiently
high frequency $\omega$. This phase-transition is different from the usual case
where two liquids are immiscible or where the slow sedimentation process of one
component (e.g. a polymer) is accelerated due to centrifugation. For a binary
mixture, the main coupling is due to a term $\propto \Delta\rho(\omega r)^2$,
where $\Delta\rho$ is the difference between the two liquid densities and $r$
the distance from the rotation axis. Below the critical temperature there is a
critical rotation frequency $\omega_c$, below which smooth density gradients
occur. When $\omega>\omega_c$, we find a sharp interface between the low
density liquid close to the center of the centrifuge and a high density liquid
far from the center. These findings may be relevant to various separation
processes and to the control of chemical reactions, in particular their
kinetics.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 06:50:14 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Dec 2007 08:59:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Tsori",
"Yoav",
""
],
[
"Leibler",
"Ludwik",
""
]
] |
0707.2267 | Avinash Singh | Pooja Srivastava, Saptarshi Ghosh, and Avinash Singh | High energy kink in the dispersion of a hole in an antiferromagnet --
double-occupancy effects on electronic excitations | 5 pages, 7 figures | Phys. Rev. B 76, 184435 (2007) | 10.1103/PhysRevB.76.184435 | null | cond-mat.str-el | null | Evolution of the hole spectral function along the Gamma-(pi,pi) cut is
studied in the antiferromagnetic state of the Hubbard model. The kink in the
calculated hole dispersion, the sharp spectral-weight transfer between the
branches, and the drastically suppressed coherent spectral weight near k=(0,0),
as observed recently in the high-resolution ARPES studies of cuprate
antiferromagnets, are shown to be strongly enhanced by finite-U
double-occupancy effects. Together with the anomalous spin-wave dispersion
observed earlier in high-resolution neutron-scattering studies, the present
study provides further evidence of a unified description of magnetic and
electronic excitations in cuprate antiferromagnets in terms of the Hubbard
model.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 06:56:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Srivastava",
"Pooja",
""
],
[
"Ghosh",
"Saptarshi",
""
],
[
"Singh",
"Avinash",
""
]
] |
0707.2268 | Azeem Mir | Azeem Mir, Farida Tahir, Kamaluddin Ahmed | Lepton Polarization Asymmetry in B l l(bar) decays in R-parity violating
Minimal Supersymmetric Standard Model | 6 pages, 4 figures Changes of notation in Eq(8-11,17-19),Eq.20 added | Europhys.Lett.83:41002,2008 | 10.1209/0295-5075/83/41002 | null | hep-ph | null | We study the implication of R-parity violating Rp Minimal Supersymmetric
Standard Model (MSSM) model in lepton polarization asymmetry ALP in B l l(bar)
decays . The analysis show that the ALP is significant in a certain
phenomenological parametric region of Yukawa couplings. We have also placed
indirect bounds on Lambda' lambda couplings as obtained from B t t(bar).
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:26:22 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Jul 2007 12:01:43 GMT"
},
{
"version": "v3",
"created": "Thu, 26 Jul 2007 07:21:49 GMT"
}
] | 2010-11-23T00:00:00 | [
[
"Mir",
"Azeem",
""
],
[
"Tahir",
"Farida",
""
],
[
"Ahmed",
"Kamaluddin",
""
]
] |
0707.2269 | Amir Levinson | Amir Levinson | Gamma Ray and Neutrino Emission as a Probe of Relativistic Jets | 6 pages; to appear in "Extragalactic Jets: Theory and Observation
from Radio to Gamma Ray", eds. T.A. Rector and D.S. De Young, ASP conf. proc | null | null | null | astro-ph | null | Constraints on the dynamics, dissipation, and production of VHE neutrinos in
relativistic jets are derived using opacity calculations and VHE $\gamma$-ray
observations. In particular, it is demonstrated how rapid variability of the
$\gamma$-ray emission at very high energies ($> 100$ GeV) can be used to map
the location of the $\gamma$-spheres, to derive lower limits on the Doppler
factor of the $\gamma$-ray emission zone, and to constrain the photopion
production opacity. The apparent discrepancy between jet Lorentz factors
inferred from superluminal motions and source statistics in the TeV blazars and
those derived from the $\gamma$-ray emission is discussed. The relation to the
high-energy emission from the HST1 knot in M87 is briefly mentioned. Estimates
of neutrino yields in upcoming neutrino telescopes are given for various
sources. It is shown that for TeV blazars, the rapid variability of the TeV
emission implies neutrino yields well below detection limit.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:37:03 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Levinson",
"Amir",
""
]
] |
0707.2270 | Damien Chablat | Damien Chablat (IRCCyN), Philippe Wenger (IRCCyN) | Design of a Spherical Wrist with Parallel Architecture: Application to
Vertebrae of an Eel Robot | null | Proc. IEEE Int. Conf. Rob. and Automation (04/2005) 1-6 | null | null | cs.RO | null | The design of a spherical wrist with parallel architecture is the object of
this article. This study is part of a larger project, which aims to design and
to build an eel robot for inspection of immersed piping. The kinematic analysis
of the mechanism is presented first to characterize the singular configurations
as well as the isotropic configurations. We add the design constraints related
to the application, such as (i) the compactness of the mechanism, (ii) the
symmetry of the elements in order to ensure static and dynamic balance and
(iii) the possibility of the mechanism to fill the elliptic form of the ell
sections.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:41:16 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Chablat",
"Damien",
"",
"IRCCyN"
],
[
"Wenger",
"Philippe",
"",
"IRCCyN"
]
] |
0707.2271 | Raffaele Romano | Raffaele Romano | Entanglement magnification induced by local manipulations | 4 pages | Phys. Rev. A 76, 042315 (2007) | 10.1103/PhysRevA.76.042315 | null | quant-ph | null | We study the entanglement capability of the evolution of a pair of qubits
evolving under unitary dynamics, when the local dynamical parameters cannot be
modified during the time-evolution. Unlike the fast local control regime, we
find that local and non-local contributions to the dynamics are strictly
interconnected. Moreover, it is possible to strongly increase the entanglement
capability by suitably initializing the characteristic energies of the two
parties.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:41:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Romano",
"Raffaele",
""
]
] |
0707.2272 | Christian Reinboth | Ulrich H.P. Fischer, Christian Reinboth, Jens-Uwe Just, Matthias Haupt | Applying the Principles of Augmented Learning to Photonics Laboratory
Work | Published at the ETOP (Education and Training in Optics and
Photonics) Conference in 2007 | null | 10.1117/12.2207925 | null | physics.optics physics.pop-ph | null | This paper introduces "OPTOTEACH", a new teaching system for photonics lab
work, designed by Harz University and successfully released on the German
market by HarzOptics. OPTOTEACH is the first POF-WDM teaching system,
specifically designed to cover a multitude of lab experiments in the field of
optical communication technology.
It is illustrated, how this lab system is supplemented by a newly developed
optical teaching software - "OPTOSOFT" - and how the combination of system and
software creates a unique augmented learning environment. The paper details,
how the didactic concept for the software was conceptualised and introduces the
latest beta version. OPTOSOFT is specifically designed not only as an
attachment to OPTOTEACH, it also allows students to rehearse various aspects of
theoretical optics and experience a fully interactive and feature-rich
self-learning environment.
The paper further details the first experiences educators at Harz University
have made working with the lab system as well as the teaching software. So far,
the augmented learning concept was received mostly positive, although there is
some potential for further optimisation concerning integration and pacing of
various interactive modules.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:52:44 GMT"
}
] | 2015-12-09T00:00:00 | [
[
"Fischer",
"Ulrich H. P.",
""
],
[
"Reinboth",
"Christian",
""
],
[
"Just",
"Jens-Uwe",
""
],
[
"Haupt",
"Matthias",
""
]
] |
0707.2273 | Jan Cie\'sli\'nski L. | Jan L. Cieslinski | Pseudospherical surfaces on time scales: a geometric definition and the
spectral approach | 20 pages | null | 10.1088/1751-8113/40/42/S02 | null | math.DG nlin.SI | null | We define and discuss the notion of pseudospherical surfaces in asymptotic
coordinates on time scales. Thus we extend well known notions of discrete
pseudospherical surfaces and smooth pseudosperical surfaces on more exotic
domains (e.g, the Cantor set). In particular, we present a new expression for
the discrete Gaussian curvature which turns out to be valid for asymptotic nets
on any time scale. We show that asymptotic Chebyshev nets on an arbitrary time
scale have constant negative Gaussian curvature. We present also the
quaternion-valued spectral problem (the Lax pair) and the Darboux-Backlund
transformation for pseudospherical surfaces (in asymptotic coordinates) on
arbitrary time scales.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:02:46 GMT"
}
] | 2009-11-20T00:00:00 | [
[
"Cieslinski",
"Jan L.",
""
]
] |
0707.2274 | Tobias Micklitz | Jan M\"uller, Tobias Micklitz, Alexander Altland | Universal spectral correlations from the ballistic sigma model | 10 pages, 3 figures | null | 10.1103/PhysRevE.76.056204 | null | nlin.CD cond-mat.mes-hall | null | We consider the semiclassical ballistic sigma-model as an effective theory
describing the quantum mechanics of classically chaotic systems. Specifically,
we elaborate on close analogies to the recently developed semiclassical theory
of quantum interference in chaotic systems and show how semiclassical
'diagrams' involving near action degenerate sets of periodic orbits emerge in
the field theoretical description. We further discuss how the universality
phenomenon (i.e. the fact that individual chaotic systems behave according to
the prescriptions of random matrix theory) can be understood from the
perspective of the field theory.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:04:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Müller",
"Jan",
""
],
[
"Micklitz",
"Tobias",
""
],
[
"Altland",
"Alexander",
""
]
] |
0707.2275 | Damien Chablat | Antoine Rennuit (IRCCyN), Alain Micaelli (CEA/LIST), Xavier Merlhiot
(CEA/LIST), Claude Andriot (CEA/LIST), Fran\c{c}ois Guillaume, Nicolas
Chevassus, Damien Chablat (IRCCyN), Patrick Chedmail (IRCCyN) | Passive Control Architecture for Virtual Humans | null | Proceeding International Conference on Intelligent Robots ans
Systems (08/2005) 1-6 | null | null | cs.RO | null | In the present paper, we introduce a new control architecture aimed at
driving virtual humans in interaction with virtual environments, by motion
capture. It brings decoupling of functionalities, and also of stability thanks
to passivity. We show projections can break passivity, and thus must be used
carefully. Our control scheme enables task space and internal control, contact,
and joint limits management. Thanks to passivity, it can be easily extended.
Besides, we introduce a new tool as for manikin's control, which makes it able
to build passive projections, so as to guide the virtual manikin when sharp
movements are needed.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:33:43 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Rennuit",
"Antoine",
"",
"IRCCyN"
],
[
"Micaelli",
"Alain",
"",
"CEA/LIST"
],
[
"Merlhiot",
"Xavier",
"",
"CEA/LIST"
],
[
"Andriot",
"Claude",
"",
"CEA/LIST"
],
[
"Guillaume",
"François",
"",
"IRCCyN"
],
[
"Chevassus",
"Nicolas",
"",
"IRCCyN"
],
[
"Chablat",
"Damien",
"",
"IRCCyN"
],
[
"Chedmail",
"Patrick",
"",
"IRCCyN"
]
] |
0707.2276 | Taro Nagao | Taro Nagao and Keiji Saito | Semiclassical Approach to Parametric Spectral Correlation with Spin 1/2 | 25 pages, 2 figures | J. Phys. A: Math. Theor. 40 (2007) 12055 | 10.1088/1751-8113/40/40/004 | null | nlin.CD | null | The spectral correlation of a chaotic system with spin 1/2 is universally
described by the GSE (Gaussian Symplectic Ensemble) of random matrices in the
semiclassical limit. In semiclassical theory, the spectral form factor is
expressed in terms of the periodic orbits and the spin state is simulated by
the uniform distribution on a sphere. In this paper, instead of the uniform
distribution, we introduce Brownian motion on a sphere to yield the parametric
motion of the energy levels. As a result, the small time expansion of the form
factor is obtained and found to be in agreement with the prediction of
parametric random matrices in the transition within the GSE universality class.
Moreover, by starting the Brownian motion from a point distribution on the
sphere, we gradually increase the effect of the spin and calculate the form
factor describing the transition from the GOE (Gaussian Orthogonal Ensemble)
class to the GSE class.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:35:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Nagao",
"Taro",
""
],
[
"Saito",
"Keiji",
""
]
] |
0707.2277 | Roland Kaiser | Roland Kaiser (Marseille, CPT) | On the two-loop contributions to the pion mass | Typos corrected and minor changes in Table 2. Published version. 19
pages, 1 figure, 2 tables | JHEP 0709:065,2007 | 10.1088/1126-6708/2007/09/065 | CPT-P32-2007 | hep-ph | null | We derive a simplified representation for the pion mass to two loops in
three-flavour chiral perturbation theory. For this purpose, we first determine
the reduced expressions for the tensorial two-loop 2-point sunset integrals
arising in chiral perturbation theory calculations. Making use of those
relations, we obtain the expression for the pion mass in terms of the minimal
set of master integrals. On the basis of known results for these, we arrive at
an explicit analytic representation, up to the contribution from K-K-eta
intermediate states where a closed-form expression for the corresponding sunset
integral is missing. However, the expansion of this function for a small pion
mass leads to a simple representation which yields a very accurate
approximation of this contribution. Finally, we also give a discussion of the
numerical implications of our results.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:52:39 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 13:45:36 GMT"
}
] | 2009-01-06T00:00:00 | [
[
"Kaiser",
"Roland",
"",
"Marseille, CPT"
]
] |
0707.2278 | Jun-Hong An | Jun-Hong An, Wei-Min Zhang | Non-Markovian entanglement dynamics of noisy continuous variable quantum
channels | The final version | Phys. Rev. A 76, 042127 (2007) | 10.1103/PhysRevA.76.042127 | null | quant-ph | null | We investigate the entanglement dynamics of continuous-variable quantum
channels in terms of an entangled squeezed state of two cavity fields in a
general non-Markovian environment. Using the Feynman-Vernon influence
functional theory in the coherent-state representation, we derive an exact
master equation with time-dependent coefficients reflecting the non-Markovian
influence of the environment. The influence of environments with different
spectral densities, e.g., Ohmic, sub-Ohmic, and super-Ohmic, is numerically
studied. The non-Markovian process shows its remarkable influences on the
entanglement dynamics due to the sensitive time-dependence of the dissipation
and noise functions within the typical time scale of the environment. The Ohmic
environment shows a weak dissipation-noise effect on the entanglement dynamics,
while the sub-Ohmic and super-Ohmic environments induce much more severe noise.
In particular, the memory of the system interacting with the environment
contributes a strong decoherence effect to the entanglement dynamics in the
super-Ohmic case.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:40:43 GMT"
},
{
"version": "v2",
"created": "Thu, 1 Nov 2007 13:59:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"An",
"Jun-Hong",
""
],
[
"Zhang",
"Wei-Min",
""
]
] |
0707.2279 | E. V. Pakhtusova | M. N. Achasov, K. I. Beloborodov, A. V. Berdyugin, A. G. Bogdanchikov,
A. D. Bukin, D. A. Bukin, T. V. Dimova, V. P. Druzhinin, V. B. Golubev, I. A.
Koop, A. A. Korol, S. V. Koshuba, E. V. Pakhtusova, E. A. Perevedentsev, S.
I. Serednyakov, Yu. M. Shatunov, Z. K. Silagadze, A. N. Skrinsky, Yu. V.
Usov, A. V. Vasiljev | Measurement of the e+e- -> K+K- cross section in the energy range
s**(1/2) = 1.04 - 1.38 GeV with the SND detector in the experiment at the
VEPP-2M e+e- collider | 20 pages, 11 figures | Phys.Rev.D76:072012,2007 | 10.1103/PhysRevD.76.072012 | null | hep-ex | null | The cross section of the process $e^+e^- \to K^+K^-$ was measured in the
energy range $\sqrt{s}$ = 1.04--1.38 GeV in the SND experiment at the VEPP-2M
$e^+e^-$ collider. The measured cross section is described by the model of
vector meson dominance with contributions from the light vector mesons $\rho$,
$\omega$, $\phi$ and their lowest excitations. The mean statistical accuracy of
the measurement is 4.4 %, and the systematic uncertainty is 5.2 %.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:47:44 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Nov 2007 09:51:29 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Achasov",
"M. N.",
""
],
[
"Beloborodov",
"K. I.",
""
],
[
"Berdyugin",
"A. V.",
""
],
[
"Bogdanchikov",
"A. G.",
""
],
[
"Bukin",
"A. D.",
""
],
[
"Bukin",
"D. A.",
""
],
[
"Dimova",
"T. V.",
""
],
[
"Druzhinin",
"V. P.",
""
],
[
"Golubev",
"V. B.",
""
],
[
"Koop",
"I. A.",
""
],
[
"Korol",
"A. A.",
""
],
[
"Koshuba",
"S. V.",
""
],
[
"Pakhtusova",
"E. V.",
""
],
[
"Perevedentsev",
"E. A.",
""
],
[
"Serednyakov",
"S. I.",
""
],
[
"Shatunov",
"Yu. M.",
""
],
[
"Silagadze",
"Z. K.",
""
],
[
"Skrinsky",
"A. N.",
""
],
[
"Usov",
"Yu. V.",
""
],
[
"Vasiljev",
"A. V.",
""
]
] |
0707.2280 | Nikolai Kolachevsky | N. Kolachevsky, A. Akimov, I. Tolstikhina, K. Chebakov, A. Sokolov, P.
Rodionov, S. Kanorski, V. Sorokin | Blue laser cooling transitions in Tm I | 8 pages, 5 figures | Appl. Phys. B 89, 589-594 (2007) | 10.1007/s00340-007-2835-z | null | physics.optics | null | We have studied possible candidates for laser cooling transitions in
$^{169}$Tm in the spectral region 410 -- 420 nm. By means of saturation
absorption spectroscopy we have measured the hyperfine structure and rates of
two nearly closed cycling transitions from the ground state
$4\textrm{f}^{13}6\textrm{s}^2(^2\textrm{F}_0)(J_g=7/2)$ to upper states
$4\textrm{f}^{12}(^3\textrm{H}_5)5\textrm{d}_{3/2}6\textrm{s}^2(J_e=9/2)$ at
410.6 nm and
$4\textrm{f}^{12}(^3\textrm{F}_4)5\textrm{d}_{5/2}6\textrm{s}^2(J_e=9/2)$ at
420.4 nm and evaluated the life times of the excited levels as 15.9(8) ns and
48(6) ns respectively. Decay rates from these levels to neighboring
opposite-parity levels are evaluated by means of Hartree-Fock calculations. We
conclude, that the strong transition at 410.6 nm has an optical leak rate of
less then $2\cdot10^{-5}$ and can be used for efficient laser cooling of
$^{169}$Tm from a thermal atomic beam. The hyperfine structure of two other
even-parity levels which can be excited from the ground state at 409.5 nm and
418.9 nm is also measured by the same technique. In addition we give a
calculated value of $7(2)$ s$^{-1}$ for the rate of magnetic-dipole transition
at 1.14 $\mu$m between the fine structure levels
$(J_g=7/2)\leftrightarrow(J'_g=5/2)$ of the ground state which can be
considered as a candidate for applications in atomic clocks.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:49:04 GMT"
},
{
"version": "v2",
"created": "Sun, 30 Dec 2007 20:25:52 GMT"
}
] | 2008-01-02T00:00:00 | [
[
"Kolachevsky",
"N.",
""
],
[
"Akimov",
"A.",
""
],
[
"Tolstikhina",
"I.",
""
],
[
"Chebakov",
"K.",
""
],
[
"Sokolov",
"A.",
""
],
[
"Rodionov",
"P.",
""
],
[
"Kanorski",
"S.",
""
],
[
"Sorokin",
"V.",
""
]
] |
0707.2281 | Linus Kramer | Linus Kramer and Katrin Tent | A Maslov cocycle for unitary groups | To appear in Proc. London Math. Soc | null | 10.1112/plms/pdp023 | null | math.KT math.GR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a 2-cocycle for symplectic and skew-hermitian hyperbolic groups
over arbitrary fields and skew fields, with values in the Witt group of
hermitian forms. This cocycle has good functorial properties: it is natural
under extension of scalars and stable, so it can be viewed as a universal
2-dimensional characteristic class for these groups. Over R and C, it coincides
with the first Chern class.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 08:56:51 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Aug 2007 16:19:36 GMT"
},
{
"version": "v3",
"created": "Mon, 20 Aug 2007 14:35:44 GMT"
},
{
"version": "v4",
"created": "Sat, 16 May 2009 08:36:26 GMT"
}
] | 2014-02-26T00:00:00 | [
[
"Kramer",
"Linus",
""
],
[
"Tent",
"Katrin",
""
]
] |
0707.2282 | Galina Lazareva G | G.G.Lazareva, A.V.Snytnikov, V.A.Vshivkov | The impact of initial density profile on protoplanetary disc evolution
simulation | 6 pages, 3 figures | Bull. Nov. Comp. Center, Comp. Science, 25 (2006), 63-68 | null | null | astro-ph | null | In the simulation of protoplanetary disc with a power law density profile a
disc instability is detected. The instability arises only with a power law
profile and is affected by power index. Thus the impact of initial density
profile is large within the employed numerical model.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:05:50 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Lazareva",
"G. G.",
""
],
[
"Snytnikov",
"A. V.",
""
],
[
"Vshivkov",
"V. A.",
""
]
] |
0707.2283 | Philip D. Mannheim | Philip D. Mannheim | Conformal Gravity Challenges String Theory | LaTex, 8 pages. Proceedings write-up of talk presented at PASCOS-07,
Imperial College London, July 2007 | null | null | null | hep-th gr-qc | null | The cosmological constant problem and the compatibility of gravity with
quantum mechanics are the two most pressing problems in all of gravitational
theory. While string theory nicely addresses the latter, it has so far failed
to provide any compelling solution to the former. On the other hand, while
conformal gravity nicely addresses the cosmological constant problem (by
naturally quenching the amount by which the cosmological constant gravitates
rather than by quenching the cosmological constant itself), the fourth order
derivative conformal theory has long been thought to possess a ghost when
quantized. However, it has recently been shown by Bender and Mannheim that not
only do theories based on fourth order derivative equations of motion not have
ghosts, they actually never had any to begin with, with the apparent presence
of ghosts being due entirely to treating operators which were not Hermitian on
the real axis as though they were. When this is taken care of via an underlying
$\cal P$$\cal T$ symmetry that such theories are found to possess, there are
then no ghosts at all and the $S$-matrix is fully unitary. Conformal gravity is
thus advanced as a fully consistent four-dimensional alternative to
ten-dimensional string theory.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:32:05 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Mannheim",
"Philip D.",
""
]
] |
0707.2284 | Wei-Xing Zhou | Xi-Yuan Qian, Fu-Tie Song, Wei-Xing Zhou (ECUST) | Nonlinear behavior of the Chinese SSEC index with a unit root: Evidence
from threshold unit root tests | 10 Elsart pages + 5 tables + 1 eps figure | Physica A 387 (2-3), 503-510 (2008) | 10.1016/j.physa.2007.09.029 | null | q-fin.ST physics.data-an physics.soc-ph | null | We investigate the behavior of the Shanghai Stock Exchange Composite (SSEC)
index for the period from 1990:12 to 2007:06 using an unconstrained two-regime
threshold autoregressive (TAR) model with an unit root developed by Caner and
Hansen. The method allows us to simultaneously consider non-stationarity and
nonlinearity in financial time series. Our finding indicates that the Shanghai
stock market exhibits nonlinear behavior with two regimes and has unit roots in
both regimes. The important implications of the threshold effect in stock
markets are also discussed.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:08:13 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Qian",
"Xi-Yuan",
"",
"ECUST"
],
[
"Song",
"Fu-Tie",
"",
"ECUST"
],
[
"Zhou",
"Wei-Xing",
"",
"ECUST"
]
] |
0707.2285 | Zheng-Tao Wei | Xue-Qian Li, Yong Liu, Zheng-Tao Wei, Liang Tang | Neutrino decay as a possible interpretation to the MiniBooNE observation
with unparticle scenario | 14 pages, conclusions are changed; published version for EPJC | Eur.Phys.J.C56:97-103,2008 | 10.1140/epjc/s10052-008-0630-6 | null | hep-ph | null | In a new measurement on neutrino oscillation $\nu_{\mu}\to\nu_e$, the
MiniBooNE Collaboration observes an excess of electron-like events at low
energy and the phenomenon may demand an explanation which obviously is beyond
the oscillation picuture. We propose that heavier neutrino $\nu_2$ decaying
into a lighter one $\nu_1$ via the transition process $\nu_{\mu}\to \nu_e+X$
where $X$ denotes any light products, could be a natural mechanism. The
theoretical model we employ here is the unparticle scenario established by
Georgi. We have studied two particular modes $\nu_\mu\to \nu_e+\Un$ and
$\nu_\mu\to \nu_e+\bar\nu_e+\nu_e$. Unfortunately, the number coming out from
the computation is too small to explain the observation. Moreover, our results
are consistent with the cosmology constraint on the neutrino lifetime and the
theoretical estimation made by other groups, therefore we can conclude that
even though neutrino decay seems plausible in this case, it indeed cannot be
the source of the peak at lower energy observed by the MiniBooNE collaboration
and there should be other mechanisms responsible for the phenomenon.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:08:30 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 12:50:16 GMT"
},
{
"version": "v3",
"created": "Sat, 3 May 2008 13:00:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Li",
"Xue-Qian",
""
],
[
"Liu",
"Yong",
""
],
[
"Wei",
"Zheng-Tao",
""
],
[
"Tang",
"Liang",
""
]
] |
0707.2286 | Pierre Rouchon | S. Bonnabel, P. Martin and P. Rouchon | Non-linear Symmetry-preserving Observer on Lie Groups | 12 pages. Submitted. Preliminary version publicated in french in the
CIFA proceedings and IFAC08 | IEEE Trans. Automatic Control. Vol 54 (7) pp:1709 - 1713, 2009 | 10.1109/TAC.2009.2020646 | null | math.OC | null | In this paper we give a geometrical framework for the design of observers on
finite-dimensional Lie groups for systems which possess some specific
symmetries. The design and the error (between true and estimated state)
equation are explicit and intrinsic. We consider also a particular case:
left-invariant systems on Lie groups with right equivariant output. The theory
yields a class of observers such that error equation is autonomous. The
observers converge locally around any trajectory, and the global behavior is
independent from the trajectory, which reminds of the linear stationary case.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:10:33 GMT"
},
{
"version": "v2",
"created": "Sat, 5 Apr 2008 14:53:28 GMT"
}
] | 2016-11-15T00:00:00 | [
[
"Bonnabel",
"S.",
""
],
[
"Martin",
"P.",
""
],
[
"Rouchon",
"P.",
""
]
] |
0707.2287 | Yaroslav Kartashov | Yaroslav V. Kartashov, Victor A. Vysloukh, Lluis Torner | Stability of vortex solitons in thermal nonlinear media with cylindrical
symmetry | 7 pages, 4 figures | Optics Express 15, 9378 (2007) | 10.1364/OE.15.009378 | null | physics.optics nlin.PS | null | We analyze the salient features of vortex-ring solitons supported by
cylindrically symmetric media with nonlocal thermal nonlinearity. We discover
the existence of a maximum allowed topological charge for such vortex solitons
to be stable on propagation: Only vortex-ring solitons with topological charge
m<=2 are found to be stable. This remarkable result holds independently of the
radius of the sample.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:11:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kartashov",
"Yaroslav V.",
""
],
[
"Vysloukh",
"Victor A.",
""
],
[
"Torner",
"Lluis",
""
]
] |
0707.2288 | Maria Lugaro | A. Bonacic Marinovic, M. Lugaro, M. Reyniers, and H. Van Winckel | Stellar population synthesis of post-AGB stars: the s-process in
MACHO47.2496.8 | accepted for publication on Astronomy & Astrophysics Letters | null | 10.1051/0004-6361:20078055 | null | astro-ph | null | The low-metallicity RV Tauri star MACHO47.2496.8, recently discovered in the
Large Magellanic Cloud, is highly enriched in carbon and heavy elements
produced by the slow neutron capture process (s-process), and is most probably
a genuine post-C(N-type) asymptotic giant branch (AGB) star. We use the
analysis of the abundances of MACHO47.2496.8 to constrain free parameters in
AGB models. We test which values of the free parameters describing uncertain
physical mechanisms in AGB stars, namely the third dredge-up and the features
of the 13C neutron source, produce models that better match the abundances
observed in MACHO47.2496.8. We carry out stellar population synthesis coupled
with s-process nucleosynthesis using a synthetic stellar evolution code. The
s-process ratios observed in MACHO47.2496.8 can be matched by the same models
that explain the s-process ratios of Galactic AGB and post-AGB stars of
metallicity > Z_sun/10, except for the choice of the effectiveness of 13C as a
neutron source, which has to be lower by roughly a factor of 3 to 6. The less
effective neutron source for lower metallicities is also required when
comparing population synthesis results to observations of Galactic halo
$s$-enhanced stars, such as Pb stars. The 12C/13C ratio in MACHO47.2496.8
cannot be matched simultaneously and requires the occurrence of extra-mixing
processes. The confirmed trend of the decreased efficiency of the 13C neutron
source with metallicity requires an explanation from AGB s-process models. The
present work is to date the first comparison between theoretical models and the
detailed abundances of an extragalactic post-AGB star.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:30:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marinovic",
"A. Bonacic",
""
],
[
"Lugaro",
"M.",
""
],
[
"Reyniers",
"M.",
""
],
[
"Van Winckel",
"H.",
""
]
] |
0707.2289 | Rainer Wanke | Rainer Wanke | Lepton Universality Tests with Kaons | 9 pages, to appear in Proceedings of Science (PoS) of KAON07
Conference; typos corrected | PoSKAON:051,2008 | null | null | hep-ex | null | Precision data on Kl3 and Kl2 decay rates and form factors allow us to
perform significant tests of lepton universality and to constrain the strength
of non-standard interactions. The present status of these tests and new physics
searches are discussed, as obtained by combining all the available results of
the various kaon physics experiments.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:22:59 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Jul 2007 14:04:29 GMT"
},
{
"version": "v3",
"created": "Fri, 21 Sep 2007 15:26:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wanke",
"Rainer",
""
]
] |
0707.2290 | Felix Finster | Felix Finster and Joel Smoller | A Time Independent Energy Estimate for Outgoing Scalar Waves in the Kerr
Geometry | 31 pages, LaTeX, minor changes (published version) | J.Hyperbol.Diff.Equat.5:221-255,2008 | 10.1142/S0219891608001453 | null | math-ph gr-qc math.MP | null | The Cauchy problem for the scalar wave equation in the Kerr geometry is
considered, with initial data which is smooth and compactly supported outside
the event horizon. A time-independent energy estimate for the outgoing wave is
obtained. As an application we estimate the outgoing energy for wave-packet
initial data, uniformly as the support of the initial data is shifted to
infinity. The main mathematical tool is our previously derived integral
representation of the wave propagator.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:33:23 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Mar 2008 09:01:28 GMT"
}
] | 2014-01-28T00:00:00 | [
[
"Finster",
"Felix",
""
],
[
"Smoller",
"Joel",
""
]
] |
0707.2291 | Marius Marin | Marius Marin, Leon Moonen, Arie van Deursen | An Integrated Crosscutting Concern Migration Strategy and its
Application to JHotDraw | 10+ 4 pages | null | null | TUD-SERG-2007-019 | cs.SE | null | In this paper we propose a systematic strategy for migrating crosscutting
concerns in existing object-oriented systems to aspect-based solutions. The
proposed strategy consists of four steps: mining, exploration, documentation
and refactoring of crosscutting concerns. We discuss in detail a new approach
to aspect refactoring that is fully integrated with our strategy, and apply the
whole strategy to an object-oriented system, namely the JHotDraw framework. The
result of this migration is made available as an open-source project, which is
the largest aspect refactoring available to date. We report on our experiences
with conducting this case study and reflect on the success and challenges of
the migration process, as well as on the feasibility of automatic aspect
refactoring.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:38:23 GMT"
},
{
"version": "v2",
"created": "Sun, 22 Jul 2007 22:13:50 GMT"
}
] | 2007-07-23T00:00:00 | [
[
"Marin",
"Marius",
""
],
[
"Moonen",
"Leon",
""
],
[
"van Deursen",
"Arie",
""
]
] |
0707.2292 | Pierre-Henri Chavanis | Pierre-Henri Chavanis | Relativistic stars with a linear equation of state: analogy with
classical isothermal spheres and black holes | A minor mistake in calculation has been corrected in the second
version (v2) | Astron. Astrophys. 483, 673 (2008) | 10.1051/0004-6361:20078287 | null | astro-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We complete our previous investigation concerning the structure and the
stability of "isothermal" spheres in general relativity. This concerns objects
that are described by a linear equation of state $P=q\epsilon$ so that the
pressure is proportional to the energy density. In the Newtonian limit $q\to
0$, this returns the classical isothermal equation of state. We consider
specifically a self-gravitating radiation (q=1/3), the core of neutron stars
(q=1/3) and a gas of baryons interacting through a vector meson field (q=1). We
study how the thermodynamical parameters scale with the size of the object and
find unusual behaviours due to the non-extensivity of the system. We compare
these scaling laws with the area scaling of the black hole entropy. We also
determine the domain of validity of these scaling laws by calculating the
critical radius above which relativistic stars described by a linear equation
of state become dynamically unstable. For photon stars, we show that the
criteria of dynamical and thermodynamical stability coincide. Considering
finite spheres, we find that the mass and entropy as a function of the central
density present damped oscillations. We give the critical value of the central
density, corresponding to the first mass peak, above which the series of
equilibria becomes unstable. Finally, we extend our results to d-dimensional
spheres. We show that the oscillations of mass versus central density disappear
above a critical dimension d_{crit}(q). For Newtonian isothermal stars (q=0) we
recover the critical dimension d_{crit}=10. For the stiffest stars (q=1) we
find d_{crit}=9 and for a self-gravitating radiation (q=1/d) we find
d_{crit}=9.96404372... very close to 10. Finally, we give analytical solutions
of relativistic isothermal spheres in 2D gravity.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:00:31 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Jul 2007 11:45:12 GMT"
},
{
"version": "v3",
"created": "Thu, 3 Sep 2009 09:18:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chavanis",
"Pierre-Henri",
""
]
] |
0707.2293 | Maziar Nekovee | Maziar Nekovee | Worm Epidemics in Wireless Adhoc Networks | null | Published in New J. Phys. 9 189, 2007 | 10.1088/1367-2630/9/6/189 | null | cs.NI cond-mat.stat-mech cs.CR physics.soc-ph | null | A dramatic increase in the number of computing devices with wireless
communication capability has resulted in the emergence of a new class of
computer worms which specifically target such devices. The most striking
feature of these worms is that they do not require Internet connectivity for
their propagation but can spread directly from device to device using a
short-range radio communication technology, such as WiFi or Bluetooth. In this
paper, we develop a new model for epidemic spreading of these worms and
investigate their spreading in wireless ad hoc networks via extensive Monte
Carlo simulations. Our studies show that the threshold behaviour and dynamics
of worm epidemics in these networks are greatly affected by a combination of
spatial and temporal correlations which characterize these networks, and are
significantly different from the previously studied epidemics in the Internet.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 09:58:18 GMT"
}
] | 2008-07-10T00:00:00 | [
[
"Nekovee",
"Maziar",
""
]
] |
0707.2294 | Raymond L. Culbertson | CDF Collaboration, T. Aaltonen, et al | Search for a High-Mass Diphoton State and Limits on Randall-Sundrum
Gravitons at CDF | submitted to Phys. Rev. Lett | Phys.Rev.Lett.99:171801,2007 | 10.1103/PhysRevLett.99.171801 | FERMILAB-PUB-07-376-E | hep-ex | null | We have performed a search for new particles which decay to two photons using
1.2/fb of integrated luminosity from p-pbar collisions at sqrt(s) = 1.96 TeV
collected using the CDF II Detector at the Fermilab Tevatron. We find the
diphoton mass spectrum to be in agreement with the standard model expectation,
and set limits on the cross section times branching ratio for the
Randall-Sundrum graviton, as a function of diphoton mass. We subsequently
derive lower limits for the graviton mass of 230 GeV/c2 and 850 GeV/c2, at the
95% confidence level, for coupling parameters (k/M_Pl) of 0.01 and 0.1
respectively.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:29:46 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jul 2007 20:57:07 GMT"
}
] | 2010-05-12T00:00:00 | [
[
"CDF Collaboration",
"",
""
],
[
"Aaltonen",
"T.",
""
]
] |
0707.2295 | Vahan Mkrtchyan | R.R. Kamalian, V. V. Mkrtchyan | Two polynomial algorithms for special maximum matching constructing in
trees | 55 pages, 38 figures, Submitted to Discrete Applied Mathematics | null | null | null | cs.DM | null | For an arbitrary tree we investigate the problems of constructing a maximum
matching which minimizes or maximizes the cardinality of a maximum matching of
the graph obtained from original one by its removal and present corresponding
polynomial algorithms.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:17:13 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Kamalian",
"R. R.",
""
],
[
"Mkrtchyan",
"V. V.",
""
]
] |
0707.2296 | Tim Browning | T.D. Browning | Counting rational points on cubic hypersurfaces | 19 pages | null | null | null | math.NT math.AG | null | Let X be a geometrically integral projective cubic hypersurface defined over
the rationals, with dimension D and singular locus of dimension at most D-4.
For any \epsilon>0, we show that X contains O(B^{D+\epsilon}) rational points
of height at most B. The implied constant in this estimate depends upon the
choice of \epsilon and the coefficients of the cubic form defining X.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:17:56 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Apr 2008 07:07:13 GMT"
}
] | 2008-04-16T00:00:00 | [
[
"Browning",
"T. D.",
""
]
] |
0707.2297 | Andrew Goodall | Andrew J. Goodall | Edge colouring models for the Tutte polynomial and related graph
invariants | 33 pages | null | null | null | math.CO | null | For integer q>1, we derive edge q-colouring models for (i) the Tutte
polynomial of a graph G on the hyperbola H_q, (ii) the symmetric weight
enumerator of the set of group-valued q-flows of G, and (iii) a more general
vertex colouring model partition function that includes these polynomials and
the principal specialization order q of Stanley's symmetric monochrome
polynomial. In the second half of the paper we exhibit a family of
non-symmetric edge q-colouring models defined on k-regular graphs, whose
partition functions for q >= k each evaluate the number of proper edge
k-colourings of G when G is Pfaffian.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:04:29 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Goodall",
"Andrew J.",
""
]
] |
0707.2298 | Alberto Lerda | Marco Billo, Marialuisa Frau, Alberto Lerda | N=2 Instanton Calculus In Closed String Background | 12 pages, 2 figures; to appear in the proceedings of 21st
Nishinomiya-Yukawa Memorial Symposium on Theoretical Physics: Noncommutative
Geometry and Quantum Spacetime in Physics, Nishinomiya and Kyoto, Japan,
11-15 Nov 2006 | null | 10.1143/PTPS.171.279 | null | hep-th | null | In this contribution we describe how to obtain instanton effects in four
dimensional gauge theories by computing string scattering amplitudes in
D3/D(-1) brane systems. In particular we study a system of fractional D3/D(-1)
branes in a Z_2 orbifold and in a Ramond-Ramond closed string background, and
show that it describes the gauge instantons of N=2 super Yang-Mills theory and
their interactions with the graviphoton of N=2. Using string theory methods we
compute the prepotential of the effective gauge theory exploiting the
localization methods of the instanton calculus, showing that this leads to the
same information given by the topological string.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:44:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Billo",
"Marco",
""
],
[
"Frau",
"Marialuisa",
""
],
[
"Lerda",
"Alberto",
""
]
] |
0707.2299 | Raul Horvat | Raul Horvat, Diego Pavon | Constraining interacting dark energy models with flux destabilization | 12 pages, minor correction, to appear in Physics Letters B | Phys.Lett.B653:373-377,2007 | 10.1016/j.physletb.2007.07.058 | null | gr-qc astro-ph hep-th | null | A destabilization in the transfer energy flux from the vacuum to radiation,
for two vacuum decay laws relevant to the dark energy problem, is analyzed
using the Landau-Lifshitz fluctuation hydrodynamic theory. Assuming thermal (or
near thermal) equilibrium between the vacuum and radiation, at the earliest
epoch of the Universe expansion, we show that the law due to
renormalization-group running of the cosmological constant term, with
parameters chosen not to spoil the primordial nucleosynthesis scenario, does
soon drive the flux to fluctuate beyond its statistical average value thereby
distorting the cosmic background radiation spectrum beyond observational
limits. While the law coming from the saturated holographic dark energy does
not lead the flux to wildly fluctuate, a more realistic non--saturated form
shows again such anomalous behavior.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:46:48 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 14:31:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Horvat",
"Raul",
""
],
[
"Pavon",
"Diego",
""
]
] |
0707.2300 | Hiroshi Fujisaki | Hiroshi Fujisaki, John E. Straub | Vibrational energy relaxation (VER) of isotopically labeled amide I
modes in cytochrome c: Theoretical investigation of VER rates and pathways | 10 pages, 5 figures, to be published in J. Phys. Chem. B | null | null | null | q-bio.BM | null | Using a time-dependent perturbation theory, vibrational energy relaxation
(VER) of isotopically labeled amide I modes in cytochrome c solvated with water
is investigated. Contributions to the VER are decomposed into two contributions
from the protein and water. The VER pathways are visualized using radial and
angular excitation functions for resonant normal modes. Key differences of VER
among different amide I modes are demonstrated, leading to a detailed picture
of the spatial anisotropy of the VER. The results support the experimental
observation that amide I modes in proteins relax with sub picosecond
timescales, while the relaxation mechanism turns out to be sensitive to the
environment of the amide I mode.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:04:29 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Fujisaki",
"Hiroshi",
""
],
[
"Straub",
"John E.",
""
]
] |
0707.2301 | Thomas Kronberger | T. Kronberger (1 and 2), W. Kapferer (1), S. Schindler (1), B. L.
Ziegler (2 and 3) ((1) Institut fuer Astro- und Teilchenphysik, Universitaet
Innsbruck, Austria, (2) Institut fuer Astrophysik, Universitaet Goettingen,
Germany, (3) Argelander-Institut fuer Astronomie, Universitaet Bonn, Germany) | 2D velocity fields of simulated interacting disc galaxies | 12 pages, 18 figures, accepted for publication in A&A, high
resolution version can be found at
http://astro.uibk.ac.at/~thomas/kronberger.pdf | null | 10.1051/0004-6361:20077696 | null | astro-ph | null | We investigate distortions in the velocity fields of disc galaxies and their
use to reveal the dynamical state of interacting galaxies at different
redshift. For that purpose, we model disc galaxies in combined
N-body/hydrodynamic simulations. 2D velocity fields of the gas are extracted
from these simulations which we place at different redshifts from z=0 to z=1 to
investigate resolution effects on the properties of the velocity field. To
quantify the structure of the velocity field we also perform a kinemetry
analysis. If the galaxy is undisturbed we find that the rotation curve
extracted from the 2D field agrees well with long-slit rotation curves. This is
not true for interacting systems, as the kinematic axis is not well defined and
does in general not coincide with the photometric axis of the system. For large
(Milky way type) galaxies we find that distortions are still visible at
intermediate redshifts but partly smeared out. Thus a careful analysis of the
velocity field is necessary before using it for a Tully-Fisher study. For small
galaxies (disc scale length ~2 kpc) even strong distortions are not visible in
the velocity field at z~0.5 with currently available angular resolution.
Therefore we conclude that current distant Tully-Fisher studies cannot give
reliable results for low-mass systems. Additionally to these studies we confirm
the power of near-infrared integral field spectrometers in combination with
adaptive optics (such as SINFONI) to study velocity fields of galaxies at high
redshift (z~2).
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 10:59:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kronberger",
"T.",
"",
"1 and 2"
],
[
"Kapferer",
"W.",
"",
"2 and 3"
],
[
"Schindler",
"S.",
"",
"2 and 3"
],
[
"Ziegler",
"B. L.",
"",
"2 and 3"
]
] |
0707.2302 | Timothy J. Hollowood | Timothy J. Hollowood and Graham M. Shore | Causality and Micro-Causality in Curved Spacetime | 16 pages, 11 figures, JHEP3, microcausality now shown to be respected
even when the Kramers-Kronig relation is violated | Phys.Lett.B655:67-74,2007 | 10.1016/j.physletb.2007.08.073 | null | hep-th gr-qc | null | We consider how causality and micro-causality are realised in QED in curved
spacetime. The photon propagator is found to exhibit novel non-analytic
behaviour due to vacuum polarization, which invalidates the Kramers-Kronig
dispersion relation and calls into question the validity of micro-causality in
curved spacetime. This non-analyticity is ultimately related to the generic
focusing nature of congruences of geodesics in curved spacetime, as implied by
the null energy condition, and the existence of conjugate points. These results
arise from a calculation of the complete non-perturbative frequency dependence
of the vacuum polarization tensor in QED, using novel world-line path integral
methods together with the Penrose plane-wave limit of spacetime in the
neighbourhood of a null geodesic. The refractive index of curved spacetime is
shown to exhibit superluminal phase velocities, dispersion, absorption (due to
\gamma \to e^+e^-) and bi-refringence, but we demonstrate that the wavefront
velocity (the high-frequency limit of the phase velocity) is indeed c, thereby
guaranteeing that causality itself is respected.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:13:48 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 13:38:27 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hollowood",
"Timothy J.",
""
],
[
"Shore",
"Graham M.",
""
]
] |
0707.2303 | Timothy J. Hollowood | Timothy J. Hollowood and Graham M. Shore | The Refractive Index of Curved Spacetime: the Fate of Causality in QED | 43 pages, 19 figures, JHEP3, conclusions respecting microcausality
modified | Nucl.Phys.B795:138-171,2008 | 10.1016/j.nuclphysb.2007.11.034 | null | hep-th gr-qc | null | It has been known for a long time that vacuum polarization in QED leads to a
superluminal low-frequency phase velocity for light propagating in curved
spacetime. Assuming the validity of the Kramers-Kronig dispersion relation,
this would imply a superluminal wavefront velocity and the violation of
causality. Here, we calculate for the first time the full frequency dependence
of the refractive index using world-line sigma model techniques together with
the Penrose plane wave limit of spacetime in the neighbourhood of a null
geodesic. We find that the high-frequency limit of the phase velocity (i.e. the
wavefront velocity) is always equal to c and causality is assured. However, the
Kramers-Kronig dispersion relation is violated due to a non-analyticity of the
refractive index in the upper-half complex plane, whose origin may be traced to
the generic focusing property of null geodesic congruences and the existence of
conjugate points. This puts into question the issue of micro-causality, i.e.
the vanishing of commutators of field operators at spacelike separated points,
in local quantum field theory in curved spacetime.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:31:48 GMT"
},
{
"version": "v2",
"created": "Mon, 29 Oct 2007 15:59:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hollowood",
"Timothy J.",
""
],
[
"Shore",
"Graham M.",
""
]
] |
0707.2304 | Gorsky Alexander | A. Gorsky and V. Mikhailov | Nonabelian strings in a dense matter | 14 pages | Phys.Rev.D76:105008,2007 | 10.1103/PhysRevD.76.105008 | null | hep-th hep-ph | null | We consider gauge theories with scalar matter with and without supersymmetry
at nonzero chemical potential. It is argued that a chemical potential plays a
role similar to the FI term. We analyze theory at weak coupling regime at large
chemical potential and argue that it supports nonabelian non-BPS strings.
Worldsheet theory on the nonabelian string in a dense matter is briefly
discussed.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:38:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gorsky",
"A.",
""
],
[
"Mikhailov",
"V.",
""
]
] |
0707.2305 | Dieter Luest | Dieter Lust | String Landscape and the Standard Model of Particle Physics | Contribution to the 11th. Marcel Grossmann Meeting on General
Relativity in Berlin, July 2006}, new refs. added, typos corrected | null | 10.1142/9789812834300_0009 | MPP-2007-94, LMU-ASC 49/07 | hep-th | null | In this paper we describe ideas about the string landscape, and how to relate
it to the physics of the Standard Model of particle physics. First, we give a
short status report about heterotic string compactifications. Then we focus on
the statistics of D-brane models, on the problem of moduli stabilization, and
finally on some attempts to derive a probability wave function in moduli space,
which goes beyond the purely statistical count of string vacua.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 11:51:31 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Jul 2007 06:23:34 GMT"
}
] | 2016-11-15T00:00:00 | [
[
"Lust",
"Dieter",
""
]
] |
0707.2306 | Andrew Goodall | Andrew J. Goodall | Parity, eulerian subgraphs and the Tutte polynomial | 31 pages | null | null | null | math.CO | null | Identities obtained by elementary finite Fourier analysis are used to derive
a variety of evaluations of the Tutte polynomial of a graph G at certain points
(a,b) where (a-1)(b-1) equals 2 or 4. These evaluations are expressed in terms
of eulerian subgraphs of G and the size of subgraphs modulo 2,3,4 or 6. In
particular, a graph is found to have a nowhere-zero 4-flow if and only if there
is a correlation between the event that three subgraphs A,B,C chosen uniformly
at random have pairwise eulerian symmetric differences and the event that the
integer part of (|A| + |B| + |C|) / 3 is even. Some further evaluations of the
Tutte polynomial at points (a,b) where (a-1)(b-1) = 3 are also given that
illustrate the unifying power of the methods used. The connection between
results of Matiyasevich, Alon and Tarsi and Onn is highlighted by indicating
how they may all be derived by the techniques adopted in this paper.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:02:06 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 11:16:23 GMT"
}
] | 2007-09-20T00:00:00 | [
[
"Goodall",
"Andrew J.",
""
]
] |
0707.2307 | Peter Talkner | Peter Talkner, Peter Hanggi, Manuel Morillo | Microcanonical quantum fluctuation theorems | revised and extended version | Phys. Rev. E 77, 051131 (2008) | 10.1103/PhysRevE.77.051131 | null | cond-mat.stat-mech | null | Previously derived expressions for the characteristic function of work
performed on a quantum system by a classical external force are generalized to
arbitrary initial states of the considered system and to Hamiltonians with
degenerate spectra. In the particular case of microcanonical initial states
explicit expressions for the characteristic function and the corresponding
probability density of work are formulated. Their classical limit as well as
their relations to the respective canonical expressions are discussed. A
fluctuation theorem is derived that expresses the ratio of probabilities of
work for a process and its time reversal to the ratio of densities of states of
the microcanonical equilibrium systems with corresponding initial and final
Hamiltonians.From this Crooks-type fluctuation theorem a relation between
entropies of different systems can be derived which does not involve the time
reversed process. This entropy-from-work theorem provides an experimentally
accessible way to measure entropies.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:11:01 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jan 2008 09:54:59 GMT"
},
{
"version": "v3",
"created": "Mon, 14 Apr 2008 09:22:07 GMT"
}
] | 2008-07-11T00:00:00 | [
[
"Talkner",
"Peter",
""
],
[
"Hanggi",
"Peter",
""
],
[
"Morillo",
"Manuel",
""
]
] |
0707.2308 | Morihiko Saito | Morihiko Saito | On real log canonical thresholds | 8 pages | null | null | null | math.AG | null | We introduce real log canonical threshold and real jumping numbers for real
algebraic functions. A real jumping number is a root of the $b$-function up to
a sign if its difference with the minimal one is less than 1. The real log
canonical threshold, which is the minimal real jumping number, coincides up to
a sign with the maximal pole of the distribution defined by the complex power
of the absolute value of the function. However, this number may be greater than
1 if the codimension of the real zero locus of the function is greater than 1.
So it does not necessarily coincide with the maximal root of the b-function up
to a sign, nor with the log canonical threshold of the complexification. In
fact, the real jumping numbers can be even disjoint from the non-integral
jumping numbers of the complexification.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:14:06 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 14:55:56 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Jul 2007 11:44:08 GMT"
}
] | 2007-07-25T00:00:00 | [
[
"Saito",
"Morihiko",
""
]
] |
0707.2309 | Christopher Smith | Christopher Smith | Recent progress on supersymmetric effects in rare K decays | Talk given at the KAON07 International Conference, May 21-25 2007,
Frascati, Italy | PoSKAON:058,2008 | null | null | hep-ph | null | The dominant MSSM effects in the rare K decays, K+ --> pi+ nu nu bar, KL -->
pi0 nu nu bar, KL --> pi0 e+ e- and KL --> pi0 mu+ mu-, are discussed both
within and without the minimal flavor violation hypothesis, at moderate and
large tangent beta. In each case, the sensitivities to MSSM soft-breaking terms
are compared, laying emphasis on possible correlations among observables. In
most scenarios, rare K decays offer unique windows into the Delta S=1 sector of
the soft-breaking terms. Therefore, together with B-physics and collider
observables, these modes will be essential for reconstructing the still elusive
SUSY-breaking mechanism.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:16:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Smith",
"Christopher",
""
]
] |
0707.2310 | Shlomo S. Razamat | Shlomo S. Razamat | On fluctuations of closed string tachyon solitons | 13 pages, 1 figure, uses JHEP3.cls | JHEP 0711:007,2007 | 10.1088/1126-6708/2007/11/007 | null | hep-th | null | We discuss fluctuations on solitons in the dilaton/graviton/tachyon system
using the low energy effective field theory approach. It is shown that closed
string solitons are free of tachyons in this approximation, regardless of the
exact shape of the tachyon potential.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:39:03 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Razamat",
"Shlomo S.",
""
]
] |
0707.2311 | Oleg Kiselev | Sergei Glebov, Oleg Kiselev, Vladimir Lazarev | The autoresonance threshold into a system of weakly coupled oscillators | LaTeX, 15 pages, 6 figures | null | null | null | math-ph math.MP | null | We investigate a system of two weakly coupled oscillators. It is shown that
an external periodic perturbation can lead to the capture into resonance.
Asymptotic description and numerical simulations are presented. We have
obtained the explicit formula for the threshold value for the amplitude of the
perturbation that leads to the autoresonance.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:25:55 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Glebov",
"Sergei",
""
],
[
"Kiselev",
"Oleg",
""
],
[
"Lazarev",
"Vladimir",
""
]
] |
0707.2312 | Sanjib Sabhapandit | Alain Comtet, Satya N. Majumdar, Stephane Ouvry and Sanjib Sabhapandit | Integer partitions and exclusion statistics: Limit shapes and the
largest part of Young diagrams | 12 pages, 4 figures (minor typo corrected) | J. Stat. Mech. (2007) P10001 | 10.1088/1742-5468/2007/10/P10001 | null | cond-mat.stat-mech math-ph math.CO math.MP | http://creativecommons.org/licenses/by/4.0/ | We compute the limit shapes of the Young diagrams of the minimal difference
$p$ partitions and provide a simple physical interpretation for the limit
shapes. We also calculate the asymptotic distribution of the largest part of
the Young diagram and show that the scaled distribution has a Gumbel form for
all $p$. This Gumbel statistics for the largest part remains unchanged even for
general partitions of the form $E=\sum_i n_i i^{1/\nu}$ with $\nu>0$ where
$n_i$ is the number of times the part $i$ appears.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:47:11 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Oct 2007 09:54:45 GMT"
},
{
"version": "v3",
"created": "Fri, 14 Jan 2022 16:04:42 GMT"
}
] | 2022-01-17T00:00:00 | [
[
"Comtet",
"Alain",
""
],
[
"Majumdar",
"Satya N.",
""
],
[
"Ouvry",
"Stephane",
""
],
[
"Sabhapandit",
"Sanjib",
""
]
] |
0707.2313 | Paul M. Terwilliger | Tatsuro Ito and Paul Terwilliger | Finite-dimensional irreducible modules for the three-point
$\mathfrak{sl}_2$ loop algebra | 45 pages | null | null | null | math.RT math.RA | null | Recently Brian Hartwig and the second author found a presentation for the
three-point $sl_2$ loop algebra by generators and relations. To obtain this
presentation they defined a Lie algebra $\boxtimes$ by generators and
relations, and displayed an isomorphism from $\boxtimes$ to the three-point
$sl_2$ loop algebra. In this paper we describe the finite-dimensional
irreducible $\boxtimes$-modules from multiple points of view.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:53:29 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Ito",
"Tatsuro",
""
],
[
"Terwilliger",
"Paul",
""
]
] |
0707.2314 | Mikhail Braun | M.A.Braun | Odderon with a running coupling constant | 9 pages, LaTex | Eur.Phys.J.C53:59-63,2008 | 10.1140/epjc/s10052-007-0428-y | null | hep-ph | null | The running coupling is introduced into the equation for the odderon via the
bootstrap relation. It is shown that the previously found odderon state with a
maximal intercept, which is constructed from antisymmetric pomeron wave
function, continues to exist in the running coupling case. Its intercept is
found to remain equal to unity independent of the behaviour assumed for the
running coupling at low momenta.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 12:54:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Braun",
"M. A.",
""
]
] |
0707.2315 | Oscar Varela | Jerome P. Gauntlett and Oscar Varela | Consistent Kaluza-Klein Reductions for General Supersymmetric AdS
Solutions | 21 pages; v2: References, some minor comments, and acknowledgements
added. Version to appear in Phys. Rev. D | Phys.Rev.D76:126007,2007 | 10.1103/PhysRevD.76.126007 | null | hep-th | null | For the most general supersymmetric solutions of type IIB supergravity
consisting of a warped product of AdS_5 with a five-dimensional manifold M_5,
we construct an explicit consistent Kaluza-Klein reduction on M_5 to minimal
D=5 gauged supergravity. Thus, any solution of the gauged supergravity can be
uplifted on M_5 to obtain an exact solution of type IIB supergravity. We also
show that for general AdS_4 x SE_7 solutions, where SE_7 is a seven-dimensional
Sasaki-Einstein manifold, and for a general class of supersymmetric solutions
that are a warped product of AdS_4 with a seven-dimensional manifold N_7, there
is an analogous consistent reduction to minimal D=4 gauged supergravity.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 13:14:40 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Nov 2007 10:26:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gauntlett",
"Jerome P.",
""
],
[
"Varela",
"Oscar",
""
]
] |
0707.2316 | Alan Duffy | Alan R. Duffy (1,2), Richard A. Battye (1), Rod D. Davies (1), Adam
Moss (3), Peter N. Wilkinson (1) ((1) Jodrell Bank Observatory, (2) Leiden
Observatory, (3) University of British Columbia) | Galaxy redshift surveys selected by neutral hydrogen using FAST | 13 pages, 15 figures, Accepted by MNRAS, minor corrections | Mon.Not.Roy.Astron.Soc.383:150-160,2008 | 10.1111/j.1365-2966.2007.12537.x | null | astro-ph | null | We discuss the possibility of performing a substantial spectroscopic galaxy
redshift survey selected via the 21cm emission from neutral hydrogen using the
Five-hundred metre Aperture Spherical Telescope (FAST) to be built in China. We
consider issues related to the estimation of the source counts and
optimizations of the survey, and discuss the constraints on cosmological models
that such a survey could provide. We find that a survey taking around two years
could detect ~10^7 galaxies with an average redshift of ~0.15 making the survey
complementary to those already carried out at optical wavelengths. These
conservative estimates have used the z=0 HI mass function and have ignored the
possibility of evolution. The results could be used to constrain Gamma =
(Omega_m h) to 5 per cent and the spectral index, n_s, to 7 per cent
independent of cosmic microwave background data. If we also use simulated power
spectra from the Planck satellite, we can constrain w to be within 5 per cent
of -1.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 18:58:33 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Apr 2008 16:06:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Duffy",
"Alan R.",
""
],
[
"Battye",
"Richard A.",
""
],
[
"Davies",
"Rod D.",
""
],
[
"Moss",
"Adam",
""
],
[
"Wilkinson",
"Peter N.",
""
]
] |
0707.2317 | Claudio Verdozzi Dr. | Claudio Verdozzi | TDDFT and Strongly Correlated Systems: Insight From Numerical Studies | 4 pages 3 figures | null | null | null | cond-mat.mes-hall cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We illustrate the scope of Time Dependent Density Functional Theory (TDDFT)
for strongly correlated (lattice) models out of equilibrium. Using the exact
many body time evolution, we reverse engineer the exact exchange correlation
(xc) potential $v_{xc}$ for small Hubbard chains exposed to time-dependent
fields. We introduce an adiabatic local density approximation (ALDA) to
$v_{xc}$ for the 1D Hubbard model and compare it to exact results, to gain
insight about approximate xc potentials. Finally, we provide some remarks on
the v-representability for the 1D Hubbard model.
| [
{
"version": "v1",
"created": "Sat, 14 Jul 2007 22:00:16 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Aug 2008 12:11:22 GMT"
}
] | 2008-08-12T00:00:00 | [
[
"Verdozzi",
"Claudio",
""
]
] |
0707.2318 | Muhammad Shoaib | Muhammad Shoaib | Angular Momentum Imparted To Test Particles by Gravitational Waves | null | null | null | null | gr-qc | null | What are gravitational waves? How do they propagate? and what is their energy
content? These questions are addressed in the first two chapters. In the third
chapter the pseudo-Newtonian formalism and its extension is reviewed in general
and the formula for the momentum imparted to test particles in arbitrary
spacetimes is reviewed in particular. In chapter four the analysis of a paper
claiming to determine the spin for gravitational waves is given, and compared
with the spin given by a geodesic analysis. It is demonstrated that the other
claim is inconsistent. Finally in chapter five a summary of the work is given
with the conclusion.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 07:29:17 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Shoaib",
"Muhammad",
""
]
] |
0707.2319 | Hrvoje Nikolic | H. Nikolic | Classical mechanics as nonlinear quantum mechanics | 7 pages, invited talk given at conference Quantum Theory:
Reconsideration of Foundations 4, Vaxjo, Sweden, June 11-16, 2007 | AIP Conf.Proc.962:162-167,2007 | 10.1063/1.2827300 | null | quant-ph hep-th | null | All measurable predictions of classical mechanics can be reproduced from a
quantum-like interpretation of a nonlinear Schrodinger equation. The key
observation leading to classical physics is the fact that a wave function that
satisfies a linear equation is real and positive, rather than complex. This has
profound implications on the role of the Bohmian classical-like interpretation
of linear quantum mechanics, as well as on the possibilities to find a
consistent interpretation of arbitrary nonlinear generalizations of quantum
mechanics.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 13:24:13 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Nikolic",
"H.",
""
]
] |
0707.2320 | Francois Arleo | Francois Arleo | Prompt photons in heavy ion collisions at the LHC: A ''multi-purpose''
observable | 2 pages, 2 figures. Presented at the Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, CERN, 14 May-8 Jun 2007 | null | null | CERN-PH-TH/2007-11, LAPTH-1197/07 | hep-ph nucl-ex nucl-th | null | I emphasize in this contribution how prompt photons can be used to probe
nuclear parton densities as well as medium-modified fragmentation functions in
heavy ion collisions. Various predictions in p-A and A-A collisions at LHC
energies are given.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 13:41:00 GMT"
}
] | 2007-07-18T00:00:00 | [
[
"Arleo",
"Francois",
""
]
] |
0707.2321 | Jaya Iyer NN | JN Iyer (IMSc, Ias) and Un Iyer (BCC, CUNY) | Chern-Simons classes of flat connections on supermanifolds | null | null | null | null | math.AG math-ph math.MP | null | In this note we define Chern-Simons classes of a superconnection $D+L$ on a
complex supervector bundle $E$ such that $D$ is flat and preserves the grading,
and $L$ is an odd endomorphism of $E$ on a supermanifold. As an application we
obtain a definition of Chern-Simons classes of a (not necessarily flat)
morphism between flat vector bundles on a smooth manifold. We extend Reznikov's
theorem on triviality of these classes when the manifold is a compact K\"ahler
manifold or a smooth complex quasi--projective variety, in degrees > 1.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:03:01 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Iyer",
"JN",
"",
"IMSc, Ias"
],
[
"Iyer",
"Un",
"",
"BCC, CUNY"
]
] |
0707.2322 | Claudia Isola | C. Isola (1), F. Favata (1), G. Micela (2) and H. S. Hudson (3) ((1)
ESA-ESTEC, Astrophysics Division - Research and Scientific Support
Department, (2) INAF, Osservatorio astronomico di Palermo,(3) Berkeley
University) | The correlation between soft and hard X-rays component in flares: from
the Sun to the stars | 9 pages, 10 figures. To be published in Astronomy and Astrophysics | null | 10.1051/0004-6361:20077643 | null | astro-ph | null | In this work we study the correlation between the soft (1.6--12.4 keV, mostly
thermal) and the hard (20--40 and 60--80 keV, mostly non-thermal) X-ray
emission in solar flares up to the most energetic events, spanning about 4
orders of magnitude in peak flux, establishing a general scaling law and
extending it to the most intense stellar flaring events observed to date. We
used the data from the Reuven Ramaty High-Energy Solar Spectroscopic Imager
(RHESSI) spacecraft, a NASA Small Explorer launched in February 2002. RHESSI
has good spectral resolution (~1 keV in the X-ray range) and broad energy
coverage (3 keV--20 MeV), which makes it well suited to distinguish the thermal
from non-thermal emission in solar flares. Our study is based on the detailed
analysis of 45 flares ranging from the GOES C-class, to the strongest X-class
events, using the peak photon fluxes in the GOES 1.6--12.4 keV and in two bands
selected from RHESSI data, i.e.20--40 keV and 60--80 keV. We find a significant
correlation between the soft and hard peak X-ray fluxes spanning the complete
sample studied. The resulting scaling law has been extrapolated to the case of
the most intense stellar flares observed, comparing it with the stellar
observations. Our results show that an extrapolation of the scaling law derived
for solar flares to the most active stellar events is compatible with the
available observations of intense stellar flares in hard X-rays.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 13:58:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Isola",
"C.",
""
],
[
"Favata",
"F.",
""
],
[
"Micela",
"G.",
""
],
[
"Hudson",
"H. S.",
""
]
] |
0707.2323 | Piotr Chankowski | Piotr H. Chankowski, Jakub Wagner | Violation of the Appelquist-Carazzone decoupling in non-SUSY GUT | 17 pages, no figures | Phys.Rev.D77:025033,2008 | 10.1103/PhysRevD.77.025033 | IFT-6/2007 | hep-ph | null | We point out that in non supersymmetric GUTs, in which the SU(5) gauge
symmetry is broken down to the Standard Model gauge group by a $\mathbf{24}$
Higgs multiplet the Appelquist-Carazzone decoupling is violated. This is
because the $SU(2)_L$ Higgs triplet contained in the $\mathbf{24}$ acquires a
dimensionfull coupling to the $SU(2)_L$ Higgs doublets which is proportional to
the GUT breaking vacuum expectation value (VEV) $V$. As a result, at one loop
heavy gauge and Higgs fields contribution to tadpoles generate a VEV of the
triplet which is not suppressed for $V\to\infty$ and violates the custodial
symmetry.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:08:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chankowski",
"Piotr H.",
""
],
[
"Wagner",
"Jakub",
""
]
] |
0707.2324 | Rakhsha Nasseripour | R. Nasseripour, M. H. Wood, C. Djalali, D. P. Weygand, C. Tur, U.
Mosel, P. Muehlich and CLAS Collaboration | Search for medium modification of the $\rho$ meson | 8 pages, 4 figures | Phys.Rev.Lett.99:262302,2007 | 10.1103/PhysRevLett.99.262302 | null | nucl-ex | null | The photoproduction of vector mesons on various nuclei has been studied using
the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. The
vector mesons, $\rho$, $\omega$, and $\phi$, are observed via their decay to
$e^+e^-$, in order to reduce the effects of final state interactions in the
nucleus. Of particular interest are possible in-medium effects on the
properties of the $\rho$ meson. The $\rho$ spectral function is extracted from
the data on various nuclei, carbon, iron, and titanium, and compared to the
spectrum from liquid deuterium, which is relatively free of nuclear effects. We
observe no significant mass shift for the $\rho$ meson; however, there is some
widening of the resonance in titanium and iron, which is consistent with
expected collisional broadening.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 16:21:16 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Jul 2007 14:44:32 GMT"
},
{
"version": "v3",
"created": "Mon, 23 Jul 2007 21:17:34 GMT"
}
] | 2010-04-06T00:00:00 | [
[
"Nasseripour",
"R.",
""
],
[
"Wood",
"M. H.",
""
],
[
"Djalali",
"C.",
""
],
[
"Weygand",
"D. P.",
""
],
[
"Tur",
"C.",
""
],
[
"Mosel",
"U.",
""
],
[
"Muehlich",
"P.",
""
],
[
"Collaboration",
"CLAS",
""
]
] |
0707.2325 | Patrick Eraerds | P. Eraerds, M. Legre, A. Rochas, H. Zbinden, N. Gisin | SiPM used as fast Photon-Counting Module and for Multiphoton Detection | 11 pages, 13 figures | null | 10.1364/OE.15.014539 | null | quant-ph astro-ph physics.bio-ph physics.ins-det | null | We demonstrate fast counting and multiphoton detection abilities of a Silicon
Photo Multiplier (SiPM). In fast counting mode we are able to detect two
consecutive photons separated by only 2.3 ns corresponding to 430 MHz. The
counting efficiency for small optical intensities at a wavelength of 532 nm was
found to be around 8.3% with a dark count rate of 50 kHz at T=-7 degrees
Celsius. Using the SiPM in multiphoton detection mode, we find a good signal
discrimination for different numbers of simultaneous detected photons.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:13:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Eraerds",
"P.",
""
],
[
"Legre",
"M.",
""
],
[
"Rochas",
"A.",
""
],
[
"Zbinden",
"H.",
""
],
[
"Gisin",
"N.",
""
]
] |
0707.2326 | Sebastian Casalaina-Martin | Sebastian Casalaina-Martin, Tawanda Gwena and Montserrat Teixidor i
Bigas | Some examples of vector bundles in the base locus of the generalized
theta divisor | 5 pages, AMS LaTEx, minor revisions | C. R. Math. Acad. Sci. Paris 347 (2009), no. 3-4, 173--176 | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper shows that on the moduli space of semi-stable vector bundles of
fixed rank and determinant (of any degree) on a smooth curve of genus at least
two, the base locus of the generalized theta divisor is large provided the rank
is sufficiently large. It also shows that the base locus is large for positive
multiples of the theta divisor. This work extends results already known for the
case where the determinant is of degree zero.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:18:58 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Jul 2012 17:59:22 GMT"
}
] | 2012-07-05T00:00:00 | [
[
"Casalaina-Martin",
"Sebastian",
""
],
[
"Gwena",
"Tawanda",
""
],
[
"Bigas",
"Montserrat Teixidor i",
""
]
] |
0707.2327 | Daniel Schaub | Fran\c{c}ois Lucas (LAREMA), Daniel Schaub (LAREMA), Mark Spivakovsky
(LEP) | On points at infinity of real spectra of polynomial rings | null | null | null | null | math.AG | null | Let R be a real closed field and A=R[x_1,...,x_n]. Let sper A denote the real
spectrum of A. There are two kinds of points in sper A : finite points (those
for which all of |x_1|,...,|x_n| are bounded above by some constant in R) and
points at infinity. In this paper we study the structure of the set of points
at infinity of sper A and their associated valuations. Let T be a subset of
{1,...,n}. For j in {1,...,n}, let y_j=x_j if j is not in T and y_j=1/x_j if j
is in T. Let B_T=R[y_1,...,y_n]. We express sper A as a disjoint union of sets
of the form U_T and construct a homeomorphism of each of the sets U_T with a
subspace of the space of finite points of sper B_T. For each point d at
infinity in U_T, we describe the associated valuation v_{d*} of its image d* in
sper B_T in terms of the valuation v_d associated to d. Among other things we
show that the valuation v_{d*} is composed with v_d (in other words, the
valuation ring R_d is a localization of R_{d*} at a suitable prime ideal).
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 19:01:28 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Lucas",
"François",
"",
"LAREMA"
],
[
"Schaub",
"Daniel",
"",
"LAREMA"
],
[
"Spivakovsky",
"Mark",
"",
"LEP"
]
] |
0707.2328 | Francois Ducastelle | Hakim Amara (LPS, PCPM, CERMIN), Christophe Bichara (CRMCN),
Fran\c{c}ois Ducastelle (LEM) | Interaction of carbon clusters with Ni(100) : Application to the
nucleation of carbon nanotubes | null | null | 10.1016/j.susc.2007.09.045 | null | cond-mat.mtrl-sci | null | In order to understand the first stages of the nucleation of carbon nanotubes
in catalytic processes, we present a tight-binding Monte Carlo study of the
stability and cohesive mechanisms of different carbon structures deposited on
nickel (100) surfaces. Depending on the geometry, we obtain contrasted results.
On the one hand, the analysis of the local energy distributions of flat carbon
sheets, demonstrate that dangling bonds remain unsaturated in spite of the
presence of the metallic catalyst. Their adhesion results from the energy gain
of the surface Ni atoms located below the carbon nanostructure. On the other
hand, carbon caps are stabilized by the presence of carbon atoms occupying the
hollow sites of the fcc nickel structure suggesting the saturation of the
dangling bonds.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:21:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Amara",
"Hakim",
"",
"LPS, PCPM, CERMIN"
],
[
"Bichara",
"Christophe",
"",
"CRMCN"
],
[
"Ducastelle",
"François",
"",
"LEM"
]
] |
0707.2329 | Jean-Pierre Vigue | Marco Abate and Jean-Pierre Vigue | Isometries for the Caratheodory Metric | 6 pages | null | null | null | math.FA math.CV | null | Under certain hypothesises, we prove that a map which is an isometry for the
Caratheodory infinitesimal metric at a point is an analytic isomorphism onto
its image.
| [
{
"version": "v1",
"created": "Mon, 16 Jul 2007 14:23:26 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 15:53:16 GMT"
}
] | 2007-09-19T00:00:00 | [
[
"Abate",
"Marco",
""
],
[
"Vigue",
"Jean-Pierre",
""
]
] |
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