id stringlengths 9 16 | title stringlengths 1 382 | abstract stringlengths 6 6.09k | categories stringlengths 5 125 |
|---|---|---|---|
0704.0201 | Hecke-Clifford algebras and spin Hecke algebras I: the classical affine
type | Associated to the classical Weyl groups, we introduce the notion of
degenerate spin affine Hecke algebras and affine Hecke-Clifford algebras. For
these algebras, we establish the PBW properties, formulate the intertwiners,
and describe the centers. We further develop connections of these algebras with
the usual degen... | math.RT math.QA |
0704.0202 | Towards Minimal Resources of Measurement-based Quantum Computation | We improve the upper bound on the minimal resources required for
measurement-based quantum computation. Minimizing the resources required for
this model is a key issue for experimental realization of a quantum computer
based on projective measurements. This new upper bound allows also to reply in
the negative to the ... | quant-ph |
0704.0203 | A Spitzer census of the IC 348 nebula | We present a Spitzer based census of the IC 348 nebula and embedded star
cluster. Our Spitzer census supplemented by ground based spectra has added 42
class II T-Tauri sources to the cluster membership and identified ~20 class 0/I
protostars. The population of IC 348 likely exceeds 400 sources after
accounting statis... | astro-ph |
0704.0204 | Non-Equilibrium Josephson and Andreev Current through Interacting
Quantum Dots | We present a theory of transport through interacting quantum dots coupled to
normal and superconducting leads in the limit of weak tunnel coupling. A
Josephson current between two superconducting leads, carried by first-order
tunnel processes, can be established by non-equilibrium proximity effect. Both
Andreev and J... | cond-mat.supr-con cond-mat.mes-hall |
0704.0205 | Discovery of X-ray emission from the young radio pulsar PSR J1357-6429 | We present the first X-ray detection of the very young pulsar PSR J1357-6429
(characteristic age of 7.3 kyr) using data from the XMM-Newton and Chandra
satellites. We find that the spectrum is well described by a power-law plus
blackbody model, with photon index Gamma=1.4 and blackbody temperature kT=160
eV. For the ... | astro-ph |
0704.0206 | Resonant activation in bistable semiconductor lasers | We theoretically investigate the possibility of observing resonant activation
in the hopping dynamics of two-mode semiconductor lasers. We present a series
of simulations of a rate-equations model under random and periodic modulation
of the bias current. In both cases, for an optimal choice of the modulation
time-sca... | physics.optics |
0704.0207 | Quark matter and the astrophysics of neutron stars | Some of the means through which the possible presence of nearly deconfined
quarks in neutron stars can be detected by astrophysical observations of
neutron stars from their birth to old age are highlighted.
| astro-ph gr-qc nucl-th |
0704.0208 | Some non-braided fusion categories of rank 3 | We classify all fusion categories for a given set of fusion rules with three
simple object types. If a conjecture of Ostrik is true, our classification
completes the classification of fusion categories with three simple object
types. To facilitate the discussion we describe a convenient, concrete and
useful variation... | math.GT math.QA |
0704.0209 | Chandra Observations of Supernova 1987A | We have been monitoring Supernova (SN) 1987A with {\it Chandra X-Ray
Observatory} since 1999. We present a review of previous results from our {\it
Chandra} observations, and some preliminary results from new {\it Chandra} data
obtained in 2006 and 2007. High resolution imaging and spectroscopic studies of
SN 1987A w... | astro-ph |
0704.0210 | Classification of superpotentials | We extend our previous classification of superpotentials of ``scalar
curvature type" for the cohomogeneity one Ricci-flat equations. We now consider
the case not covered in our previous paper, i.e., when some weight vector of
the superpotential lies outside (a scaled translate of) the convex hull of the
weight vector... | math.DG |
0704.0211 | Linkedness and ordered cycles in digraphs | The minimum semi-degree of a digraph D is the minimum of its minimum
outdegree and its minimum indegree. We show that every sufficiently large
digraph D with minimum semi-degree at least n/2 +k-1 is k-linked. The bound on
the minimum semi-degree is best possible and confirms a conjecture of
Manoussakis from 1990. We ... | math.CO |
0704.0212 | Curvature and isocurvature perturbations in two-field inflation | We study cosmological perturbations in two-field inflation, allowing for
non-standard kinetic terms. We calculate analytically the spectra of curvature
and isocurvature modes at Hubble crossing, up to first order in the slow-roll
parameters. We also compute numerically the evolution of the curvature and
isocurvature ... | hep-th astro-ph gr-qc |
0704.0213 | Geometric Complexity Theory V: On deciding nonvanishing of a generalized
Littlewood-Richardson coefficient | This article has been withdrawn because it has been merged with the earlier
article GCT3 (arXiv: CS/0501076 [cs.CC]) in the series. The merged article is
now available as:
Geometric Complexity Theory III: on deciding nonvanishing of a
Littlewood-Richardson Coefficient, Journal of Algebraic Combinatorics, vol. 36,
i... | cs.CC |
0704.0214 | A schematic model of scattering in PT-symmetric Quantum Mechanics | One-dimensional scattering problem admitting a complex, PT-symmetric
short-range potential V(x) is considered. Using a Runge-Kutta-discretized
version of Schroedinger equation we derive the formulae for the reflection and
transmission coefficients and emphasize that the only innovation emerges in
fact via a complexif... | quant-ph hep-th |
0704.0215 | The exact asymptotic of the collision time tail distribution for
independent Brownian particles with different drifts | In this note we consider the time of the collision $\tau$ for $n$ independent
Brownian motions $X^1_t,...,X_t^n$ with drifts $a_1,...,a_n$, each starting
from $x=(x_1,...,x_n)$, where $x_1<...<x_n$. We show the exact asymptotics of
$P_x(\tau>t) = C h(x)t^{-\alpha}e^{-\gamma t}(1 + o(1))$ as $t\to\infty$ and
identify ... | math.PR |
0704.0216 | Ab initio Study of Graphene on SiC | Employing density-functional calculations we study single and double graphene
layers on Si- and C-terminated 1x1-6H-SiC surfaces. We show that, in contrast
to earlier assumptions, the first carbon layer is covalently bonded to the
substrate, and cannot be responsible for the graphene-type electronic spectrum
observed... | cond-mat.mtrl-sci |
0704.0217 | Capacity of a Multiple-Antenna Fading Channel with a Quantized Precoding
Matrix | Given a multiple-input multiple-output (MIMO) channel, feedback from the
receiver can be used to specify a transmit precoding matrix, which selectively
activates the strongest channel modes. Here we analyze the performance of
Random Vector Quantization (RVQ), in which the precoding matrix is selected
from a random co... | cs.IT math.IT |
0704.0218 | On Almost Periodicity Criteria for Morphic Sequences in Some Particular
Cases | In some particular cases we give criteria for morphic sequences to be almost
periodic (=uniformly recurrent). Namely, we deal with fixed points of
non-erasing morphisms and with automatic sequences. In both cases a
polynomial-time algorithm solving the problem is found. A result more or less
supporting the conjecture... | cs.DM cs.LO |
0704.0219 | The Radio Emission, X-ray Emission, and Hydrodynamics of G328.4+0.2: A
Comprehensive Analysis of a Luminous Pulsar Wind Nebula, its Neutron Star,
and the Progenitor Supernova Explosion | We present new observational results obtained for the Galactic non-thermal
radio source G328.4+0.2 to determine both if this source is a pulsar wind
nebula or supernova remnant, and in either case, the physical properties of
this source. Using X-ray data obtained by XMM, we confirm that the X-ray
emission from this s... | astro-ph |
0704.0220 | Three Particle Correlations from STAR | Two-particle correlations have shown modification to the away-side shape in
central Au+Au collisions relative to $pp$, d+Au and peripheral Au+Au
collisions. Different scenarios can explain this modification including: large
angle gluon radiation, jets deflected by transverse flow, path length dependent
energy loss, C... | nucl-ex |
0704.0221 | The Return of a Static Universe and the End of Cosmology | We demonstrate that as we extrapolate the current $\Lambda$CDM universe
forward in time, all evidence of the Hubble expansion will disappear, so that
observers in our "island universe" will be fundamentally incapable of
determining the true nature of the universe, including the existence of the
highly dominant vacuum... | astro-ph gr-qc hep-ph hep-th |
0704.0222 | Dark Matter annihilation in Draco: new considerations on the expected
gamma flux | A new estimation of the gamma-ray flux that we expect to detect from SUSY
dark matter annihilation from the Draco dSph is presented using the DM density
profiles compatible with the latest observations. This calculation takes also
into account the important effect of the Point Spread Function (PSF) of the
telescope. ... | astro-ph |
0704.0223 | Magnetohydrodynamic Rebound Shocks of Supernovae | We construct magnetohydrodynamic (MHD) similarity rebound shocks joining
`quasi-static' asymptotic solutions around the central degenerate core to
explore an MHD model for the evolution of random magnetic field in supernova
explosions. This provides a theoretical basis for further studying synchrotron
diagnostics, MH... | astro-ph |
0704.0224 | Are There Mach Cones in Heavy Ion Collisions? Three-Particle
Correlations from STAR | We present results from STAR on 3-particle azimuthal correlations for a
$3<p_T<4$ GeV/c trigger particle with two softer $1<p_T<2$ GeV/c particles.
Results are shown for pp, d+Au and high statistics Au+Au collisions at
$\sqrt{s_{NN}}=200 GeV$. We observe a 3-particle correlation in central Au+Au
collisions which may ... | nucl-ex |
0704.0225 | Exploring First Stars Era with GLAST | Cosmic infrared background (CIB) includes emissions from objects inaccessible
to current telescopic studies, such as the putative Population III, the first
stars. Recently, strong direct evidence for significant CIB levels produced by
the first stars came from CIB fluctuations discovered in deep Spitzer images.
Such ... | astro-ph |
0704.0226 | Correlated modulation between the redshifted Fe K alpha line and the
continuum emission in NGC 3783 | It has been suggested that X-ray observations of rapidly variable Seyfert
galaxies may hold the key to probe the gas orbital motions in the innermost
regions of accretion discs around black holes and, thus, trace flow patterns
under the effect of the hole strong gravitational field. We explore this
possibility analiz... | astro-ph |
0704.0227 | Isotopic Effects in Nuclear Reactions at Relativistic Energies | A systematic study of isotopic effects in the break-up of projectile
spectators at relativistic energies has been performed at the GSI laboratory
with the ALADiN spectrometer coupled to the LAND neutron detector. Besides a
primary beam of 124Sn, also secondary beams of 124La and 107Sn produced at the
FRS fragment sep... | nucl-ex |
0704.0228 | Einstein vs Maxwell: Is gravitation a curvature of space, a field in
flat space, or both? | Starting with a field theoretic approach in Minkowski space, the
gravitational energy momentum tensor is derived from the Einstein equations in
a straightforward manner. This allows to present them as {\it acceleration
tensor} = const. $\times$ {\it total energy momentum tensor}. For flat space
cosmology the gravitat... | gr-qc astro-ph quant-ph |
0704.0229 | Geometric Complexity Theory VI: the flip via saturated and positive
integer programming in representation theory and algebraic geometry | This article belongs to a series on geometric complexity theory (GCT), an
approach to the P vs. NP and related problems through algebraic geometry and
representation theory. The basic principle behind this approach is called the
flip. In essence, it reduces the negative hypothesis in complexity theory (the
lower boun... | cs.CC |
0704.0230 | Two new basaltic asteroids in the Outer Main Belt? | The identification of basaltic asteroids in the asteroid Main Belt and the
description of their surface mineralogy is necessary to understand the
diversity in the collection of basaltic meteorites. Basaltic asteroids can be
identified from their visible reflectance spectra and are classified as V-type
in the usual ta... | astro-ph |
0704.0231 | Interpolating and sampling sequences in finite Riemann surfaces | We provide a description of the interpolating and sampling sequences on a
space of holomorphic functions with a uniform growth restriction defined on
finite Riemann surfaces.
| math.CV |
0704.0232 | New algebraic aspects of perturbative and non-perturbative Quantum Field
Theory | In this expository article we review recent advances in our understanding of
the combinatorial and algebraic structure of perturbation theory in terms of
Feynman graphs, and Dyson-Schwinger equations. Starting from Lie and Hopf
algebras of Feynman graphs, perturbative renormalization is rephrased
algebraically. The H... | hep-th |
0704.0233 | Many-body interband tunneling as a witness for complex dynamics in the
Bose-Hubbard model | A perturbative model is studied for the tunneling of many-particle states
from the ground band to the first excited energy band, mimicking Landau-Zener
decay for ultracold, spinless atoms in quasi-one dimensional optical lattices
subjected to a tunable tilting force. The distributions of the computed
tunneling rates ... | cond-mat.other |
0704.0234 | Comments on ``Are Swift Gamma-Ray Bursts consistent with the Ghirlanda
relation?", by Campana et al.(astro--ph/0703676) | In their recent paper, Campana et al. (2007) found that 5 bursts, among those
detected by Swift, are outliers with respect to the E_peak-E_gamma
("Ghirlanda") correlation. We instead argue that they are not.
| astro-ph |
0704.0235 | The Determination of the Helicity of $W'$ Boson Couplings at the LHC | Apart from its mass and width, the most important property of a new charged
gauge boson, $W'$, is the helicity of its couplings to the SM fermions. Such
particles are expected to exist in many extensions of the Standard Model. In
this paper we explore the capability of the LHC to determine the $W'$ coupling
helicity ... | hep-ph hep-ex |
0704.0236 | Curvature flows in semi-Riemannian manifolds | We prove that the limit hypersurfaces of converging curvature flows are
stable, if the initial velocity has a weak sign, and give a survey of the
existence and regularity results.
| math.DG |
0704.0237 | Hydrodynamic and Spectral Simulations of HMXB Winds | We describe preliminary results of a global model of the radiatively-driven
photoionized wind and accretion flow of the high-mass X-ray binary Vela X-1.
The full model combines FLASH hydrodynamic calculations, XSTAR photoionization
calculations, HULLAC atomic data, and Monte Carlo radiation transport. We
present maps... | astro-ph |
0704.0238 | Radio Astrometric Detection and Characterization of Extra-Solar Planets:
A White Paper Submitted to the NSF ExoPlanet Task Force | The extraordinary astrometric accuracy of radio interferometry creates an
important and unique opportunity for the discovery and characterization of
exo-planets. Currently, the Very Long Baseline Array can routinely achieve
better than 100 microarcsecond accuracy, and can approach 10 microarcsecond
with careful calib... | astro-ph |
0704.0239 | Interface dynamics of microscopic cavities in water | An analytical description of the interface motion of a collapsing
nanometer-sized spherical cavity in water is presented by a modification of the
Rayleigh-Plesset equation in conjunction with explicit solvent molecular
dynamics simulations. Quantitative agreement is found between the two
approaches for the time-depen... | cond-mat.soft |
0704.0240 | Viscosity, Black Holes, and Quantum Field Theory | We review recent progress in applying the AdS/CFT correspondence to
finite-temperature field theory. In particular, we show how the hydrodynamic
behavior of field theory is reflected in the low-momentum limit of correlation
functions computed through a real-time AdS/CFT prescription, which we
formulate. We also show ... | hep-th |
0704.0241 | Superconducting states of the quasi-2D Holstein model: Effects of vertex
and non-local corrections | I investigate superconducting states in a quasi-2D Holstein model using the
dynamical cluster approximation (DCA). The effects of spatial fluctuations
(non-local corrections) are examined and approximations neglecting and
incorporating lowest-order vertex corrections are computed. The approximation
is expected to be ... | cond-mat.supr-con |
0704.0242 | Masers and star formation | Recent observational and theoretical advances concerning astronomical masers
in star forming regions are reviewed. Major masing species are considered
individually and in combination. Key results are summarized with emphasis on
present science and future prospects.
| astro-ph |
0704.0243 | Renormalized quasiparticles in antiferromagnetic states of the Hubbard
model | We analyze the properties of the quasiparticle excitations of metallic
antiferromagnetic states in a strongly correlated electron system. The study is
based on dynamical mean field theory (DMFT) for the infinite dimensional
Hubbard model with antiferromagnetic symmetry breaking. Self-consistent
solutions of the DMFT ... | cond-mat.str-el |
0704.0244 | Comparison of exact-exchange calculations for solids in
current-spin-density- and spin-density-functional theory | The relative merits of current-spin-density- and spin-density-functional
theory are investigated for solids treated within the exact-exchange-only
approximation. Spin-orbit splittings and orbital magnetic moments are
determined at zero external magnetic field. We find that for magnetic (Fe, Co
and Ni) and non-magneti... | cond-mat.mtrl-sci |
0704.0245 | One-loop MHV Rules and Pure Yang-Mills | It has been known for some time that the standard MHV diagram formulation of
perturbative Yang-Mills theory is incomplete, as it misses rational terms in
one-loop scattering amplitudes of pure Yang-Mills. We propose that certain
Lorentz violating counterterms, when expressed in the field variables which
give rise to ... | hep-th hep-ph |
0704.0246 | Fermi-liquid effects in the transresistivity in quantum Hall double
layers near $\nu= 1/2 $ | Here, we present theoretical studies of the temperature and magnetic field
dependences of the Coulomb drag transresistivity between two parallel layers of
two dimensional electron gases in quantum Hall regime near half filling of the
lowest Landau level. It is shown that Fermi-liquid interactions between the
relevant... | cond-mat.mes-hall |
0704.0247 | Geometry of four-dimensional Killing spinors | The supersymmetric solutions of N=2, D=4 minimal ungauged and gauged
supergravity are classified according to the fraction of preserved
supersymmetry using spinorial geometry techniques. Subject to a reasonable
assumption in the 1/2-supersymmetric time-like case of the gauged theory, we
derive the complete form of al... | hep-th gr-qc |
0704.0248 | A Rigorous Time-Domain Analysis of Full--Wave Electromagnetic Cloaking
(Invisibility) | There is currently a great deal of interest in the theoretical and practical
possibility of cloaking objects from the observation by electromagnetic waves.
The basic idea of these invisibility devices \cite{glu1, glu2, le},\cite{pss1}
is to use anisotropic {\it transformation media} whose permittivity and
permeabilit... | physics.optics math-ph math.MP |
0704.0249 | Non-perturbative conserving approximations and Luttinger's sum rule | Weak-coupling conserving approximations can be constructed by truncations of
the Luttinger-Ward functional and are well known as thermodynamically
consistent approaches which respect macroscopic conservation laws as well as
certain sum rules at zero temperature. These properties can also be shown for
variational appr... | cond-mat.str-el |
0704.0250 | 2D-MIT as self-doping of a Wigner-Mott insulator | We consider an interaction-driven scenario for the two-dimensional
metal-insulator transition in zero magnetic field (2D-MIT), based on melting
the Wigner crystal through vacancy-interstitial pair formation. We show that
the transition from the Wigner-Mott insulator to a heavy Fermi liquid emerges
as an instability t... | cond-mat.str-el cond-mat.dis-nn |
0704.0251 | Entanglement of Subspaces and Error Correcting Codes | We introduce the notion of entanglement of subspaces as a measure that
quantify the entanglement of bipartite states in a randomly selected subspace.
We discuss its properties and in particular we show that for maximally
entangled subspaces it is additive. Furthermore, we show that maximally
entangled subspaces can p... | quant-ph |
0704.0252 | Does the present data on B_s - bar B_s mixing rule out a large
enhancement in the branching ratio of B_s --> mu+ mu- ? | In this letter, we consider the constraints imposed by the recent measurement
of B_s - bar B_s mixing on the new physics contribution to the rare decay B_s
--> mu+ mu-. New physics in the form vector and axial-vector couplings is
already severely constrained by the data on B --> (K,K*) mu+ mu-. Here, we show
that B_s... | hep-ph |
0704.0253 | The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds VIII.
Serpens Observed with MIPS | We present maps of 1.5 square degrees of the Serpens dark cloud at 24, 70,
and 160\micron observed with the Spitzer Space Telescope MIPS Camera. More than
2400 compact sources have been extracted at 24um, nearly 100 at 70um, and 4 at
160um. We estimate completeness limits for our 24um survey from Monte Carlo
tests wi... | astro-ph |
0704.0254 | Unravelling the sbottom spin at the CERN LHC | Establishing that a signal of new physics is undoubtly supersymmetric
requires not only the discovery of the supersymmetric partners but also probing
their spins and couplings. We show that the sbottom spin can be probed at the
CERN Large Hadron Collider using only angular correlations in sbottom pair
production with... | hep-ph |
0704.0255 | Modeling the three-point correlation function | We present new predictions for the galaxy three-point correlation function
(3PCF) using high-resolution dissipationless cosmological simulations of a flat
LCDM Universe which resolve galaxy-size halos and subhalos. We create realistic
mock galaxy catalogs by assigning luminosities and colors to dark matter halos
and ... | astro-ph |
0704.0256 | Multi-spectral Observations of Lunar Occultations: I. Resolving The Dust
Shell Around AFGL 5440 | We present observations and modeling of a lunar occultation of the
dust-enshrouded carbon star AFGL 5440. The observations were made over a
continuous range of wavelengths from 1 - 4um with a high-speed
spectrophotometer designed expressly for this purpose. We find that the
occultation fringes cannot be fit by any si... | astro-ph |
0704.0257 | Orbifold cohomology of abelian symplectic reductions and the case of
weighted projective spaces | These notes accompany a lecture about the topology of symplectic (and other)
quotients. The aim is two-fold: first to advertise the ease of computation in
the symplectic category; and second to give an account of some new computations
for weighted projective spaces. We start with a brief exposition of how
orbifolds a... | math.SG math.AG |
0704.0258 | Correlation functions in the Non Perturbative Renormalization Group and
field expansion | The usual procedure of including a finite number of vertices in Non
Perturbative Renormalization Group equations in order to obtain $n$-point
correlation functions at finite momenta is analyzed. This is done by exploiting
a general method recently introduced which includes simultaneously all vertices
although approxi... | hep-th cond-mat.stat-mech |
0704.0259 | Formation and Collisional Evolution of Kuiper Belt Objects | This chapter summarizes analytic theory and numerical calculations for the
formation and collisional evolution of KBOs at 20--150 AU. We describe the main
predictions of a baseline self-stirring model and show how dynamical
perturbations from a stellar flyby or stirring by a giant planet modify the
evolution. Althoug... | astro-ph |
0704.0260 | On Existence of Boundary Values of Polyharmonic Functions | In trigonometric series terms all polyharmonic functions inside the unit disk
are described. For such functions it is proved the existence of their boundary
values on the unit circle in the space of hyperfunctions. The necessary and
sufficient conditions are presented for the boundary value to belong to certain
subsp... | math.FA math.AP |
0704.0261 | Constraints on the Self-Interaction Cross-Section of Dark Matter from
Numerical Simulations of the Merging Galaxy Cluster 1E 0657-5 | (Abridged) We compare recent results from X-ray, strong lensing, weak
lensing, and optical observations with numerical simulations of the merging
galaxy cluster 1E0657-56. X-ray observations reveal a bullet-like subcluster
with a prominent bow shock, while lensing results show that the positions of
the total mass pea... | astro-ph |
0704.0262 | Stringy Instantons at Orbifold Singularities | We study the effects produced by D-brane instantons on the holomorphic
quantities of a D-brane gauge theory at an orbifold singularity. These effects
are not limited to reproducing the well known contributions of the gauge theory
instantons but also generate extra terms in the superpotential or the
prepotential. On t... | hep-th |
0704.0263 | Turbulent Diffusion of Lines and Circulations | We study material lines and passive vectors in a model of turbulent flow at
infinite-Reynolds number, the Kraichnan-Kazantsev ensemble of velocities that
are white-noise in time and rough (Hoelder continuous) in space. It is argued
that the phenomenon of ``spontaneous stochasticity'' generalizes to material
lines and... | physics.flu-dyn physics.plasm-ph |
0704.0264 | Gluon Radiation of an Expanding Color Skyrmion in the Quark-Gluon Plasma | The density of states and energy spectrum of the gluon radiation are
calculated for the color current of an expanding hydrodynamic skyrmion in the
quark gluon plasma with a semiclassical method. Results are compared with those
in literatures.
| hep-ph hep-th nucl-th |
0704.0265 | REM near-IR and optical multiband observations of PKS2155-304 in 2005 | Spectral variability is the main tool for constraining emission models of BL
Lac objects. By means of systematic observations of the BL Lac prototype PKS
2155-304 in the infrared-optical band, we explore variability on the scales of
months, days and hours. We made our observations with the robotic 60 cm
telescope R... | astro-ph |
0704.0266 | Supernova Polarization and the Type IIn Classification | While the members of the Type IIn category of supernovae are united by the
presence of strong multicomponent Balmer emission lines in their spectra, they
are quite heterogeneous with respect to other properties such as Balmer line
profiles, light curves, strength of radio emission, and intrinsic brightness.
We are no... | astro-ph |
0704.0267 | Near-Infrared Spectra of the Black Hole X-Ray Binary, A0620-00 | We present broadband NIR spectra of A0620-00 obtained with SpeX on the IRTF.
The spectrum is characterized by a blue continuum on which are superimposed
broad emission lines of HI and HeII and a host of narrower absorption lines of
neutral metals and molecules. Spectral type standard star spectra scaled to the
deredd... | astro-ph |
0704.0268 | Automated Generation of Layout and Control for Quantum Circuits | We present a computer-aided design flow for quantum circuits, complete with
automatic layout and control logic extraction. To motivate automated layout for
quantum circuits, we investigate grid-based layouts and show a performance
variance of four times as we vary grid structure and initial qubit placement.
We then p... | quant-ph |
0704.0269 | Modeling the Spectral Energy Distribution and Variability of 3C 66A
during the WEBT campaign of 2003 -- 2004 | The BL Lac object 3C 66A was observed in an extensive multiwavelength
monitoring campaign from July 2003 till April 2004. The spectral energy
distribution (SED) was measured over the entire electromagnetic spectrum, with
flux measurements from radio to X-ray frequencies and upper limits in the very
high energy (VHE) ... | astro-ph |
0704.0270 | The HARPS search for southern extra-solar planets. X. A m sin i = 11
Mearth planet around the nearby spotted M dwarf GJ 674 | Context: How planet properties depend on stellar mass is a key diagnostic of
planetary formation mechanisms. Aims: This motivates planet searches around
stars which are significantly more massive or less massive than the Sun, and in
particular our radial velocity search for planets around very-low mass stars.
Methods... | astro-ph |
0704.0271 | An individual based model with global competition interaction:
fluctuations effects in pattern formation | We present some numerical results obtained from a simple individual based
model that describes clustering of organisms caused by competition. Our aim is
to show how, even when a deterministic description developed for continuum
models predicts no pattern formation, an individual based model displays well
defined patt... | cond-mat.stat-mech q-bio.PE |
0704.0272 | A Comparison between Anomalous 6-cm H$_2$CO Absorption and CO(1-0)
Emission in the L1204/S140 | We report observations of the dust cloud L1204 with the Onsala 25-m telescope
in the 6 cm (1$_{11}-1_{10}$) transition of \htco. The observed region includes
the
S140 H${\alpha}$ arc. This spectral line is seen here in absorption against
the cosmic microwave background, indicating the presence of widespread warm
mo... | astro-ph |
0704.0273 | Dimers on surface graphs and spin structures. II | In a previous paper, we showed how certain orientations of the edges of a
graph G embedded in a closed oriented surface S can be understood as discrete
spin structures on S. We then used this correspondence to give a geometric
proof of the Pfaffian formula for the partition function of the dimer model on
G. In the pr... | math-ph math.GT math.MP |
0704.0274 | New version announcement for TaylUR, an arbitrary-order diagonal
automatic differentiation package for Fortran 95 | We present a new version of TaylUR, a Fortran 95 module to automatically
compute the numerical values of a complex-valued function's derivatives with
respect to several variables up to an arbitrary order in each variable, but
excluding mixed derivatives. The new version fixes a potentially serious bug in
the code for... | physics.comp-ph |
0704.0275 | Mapping radii of metric spaces | It is known that every closed curve of length \leq 4 in R^n (n>0) can be
surrounded by a sphere of radius 1, and that this is the best bound. Letting S
denote the circle of circumference 4, with the arc-length metric, we here
express this fact by saying that the "mapping radius" of S in R^n is 1.
Tools are develope... | math.MG |
0704.0276 | A New Model For The Loop-I (The North Polar Spur) Region | The North Polar Spur (NPS) is the brightest filament of Loop I, a large
circular feature in the radio continuum sky. In this paper, a model consisting
of two synchrotron emitting shells is presented that reproduces large-scale
structures revealed by recent polarization surveys. The polarized emission of
the NPS is re... | astro-ph |
0704.0277 | Leray numbers of projections and a topological Helly type theorem | Let X be a simplicial complex on the vertex set V. The rational Leray number
L(X) of X is the minimal d such that the rational reduced homology of any
induced subcomplex of X vanishes in dimensions d and above. Let \pi be a
simplicial map from X to a simplex Y, such that the cardinality of the preimage
of any point i... | math.CO |
0704.0278 | q-Deformed spin foam models of quantum gravity | We numerically study Barrett-Crane models of Riemannian quantum gravity. We
have extended the existing numerical techniques to handle q-deformed models and
arbitrary space-time triangulations. We present and interpret expectation
values of a few selected observables for each model, including a spin-spin
correlation f... | gr-qc |
0704.0279 | HI velocity dispersion in NGC 1058 | We present excellent resolution and high sensitivity Very Large Array (VLA)
observations of the 21cm HI line emission from the face-on galaxy NGC 1058,
providing the first reliable study of the HI profile shapes throughout the
entire disk of an external galaxy. Our observations show an intriguing picture
of the inter... | astro-ph |
0704.0280 | Common Envelope Evolution Redux | Common envelopes form in dynamical time scale mass exchange, when the
envelope of a donor star engulfs a much denser companion, and the core of the
donor plus the dense companion star spiral inward through this dissipative
envelope. As conceived by Paczynski and Ostriker, this process must be
responsible for the crea... | astro-ph |
0704.0281 | The Source of Turbulence in Astrophysical Disks: An Ill-posed Problem. | An critical overview of the current state of research in turbulence in
astrophysical disks.
| astro-ph |
0704.0282 | On Punctured Pragmatic Space-Time Codes in Block Fading Channel | This paper considers the use of punctured convolutional codes to obtain
pragmatic space-time trellis codes over block-fading channel. We show that good
performance can be achieved even when puncturation is adopted and that we can
still employ the same Viterbi decoder of the convolutional mother code by using
approxim... | cs.IT cs.CC math.IT |
0704.0283 | On the Markov trace for Temperley--Lieb algebras of type $E_n$ | We show that there is a unique Markov trace on the tower of Temperley--Lieb
type quotients of Hecke algebras of Coxeter type $E_n$ (for all $n \geq 6$). We
explain in detail how this trace may be computed easily using tom Dieck's
calculus of diagrams. As applications, we show how to use the trace to show
that the dia... | math.QA |
0704.0284 | Second Order Perturbative Calculation of Quasinormal Modes of
Schwarzschild Black Holes | We analytically calculate to second order the correction to the asymptotic
form of quasinormal frequencies of four dimensional Schwarzschild black holes
based on the monodromy analysis proposed by Motl and Neitzke. Our results are
in good agreement with those obtained from numerical calculation.
| hep-th gr-qc |
0704.0285 | Epitaxial graphene | Graphene multilayers are grown epitaxially on single crystal silicon carbide.
This system is composed of several graphene layers of which the first layer is
electron doped due to the built-in electric field and the other layers are
essentially undoped. Unlike graphite the charge carriers show Dirac particle
propertie... | cond-mat.mes-hall cond-mat.mtrl-sci |
0704.0286 | Mathematics of thermoacoustic tomography | The paper presents a survey of mathematical problems, techniques, and
challenges arising in the Thermoacoustic and Photoacoustic Tomography.
| math.AP math-ph math.MP |
0704.0287 | Search for Very High Energy Emission from Gamma-Ray Bursts using Milagro | Gamma-Ray Bursts (GRBs) have been detected at GeV energies by EGRET and
models predict emission at > 100 GeV. Milagro is a wide field (2 sr) high duty
cycle (> 90 %) ground based water Cherenkov detector that records extensive air
showers in the energy range 100 GeV to 100 TeV. We have searched for very high
energy e... | astro-ph |
0704.0288 | Specific heat and bimodality in canonical and grand canonical versions
of the thermodynamic model | We address two issues in the thermodynamic model for nuclear disassembly.
Surprisingly large differences in results for specific heat were seen in
predictions from the canonical and grand canonical ensembles when the nuclear
system passes from liquid-gas co-existence to the pure gas phase. We are able
to pinpoint and... | nucl-th |
0704.0289 | Vortex proliferation in the Berezinskii-Kosterlitz-Thouless regime on a
two-dimensional lattice of Bose-Einstein condensates | We observe the proliferation of vortices in the
Berezinskii-Kosterlitz-Thouless regime on a two-dimensional array of
Josephson-coupled Bose-Einstein condensates. As long as the Josephson
(tunneling) energy J exceeds the thermal energy T, the array is vortex-free.
With decreasing J/T, vortices appear in the system in ... | cond-mat.mes-hall |
0704.0290 | The core binary fractions of star clusters from realistic simulations | We investigate the evolution of binary fractions in star clusters using
N-body models of up to 100000 stars. Primordial binary frequencies in these
models range from 5% to 50%. Simulations are performed with the NBODY4 code and
include a full mass spectrum of stars, stellar evolution, binary evolution and
the tidal f... | astro-ph |
0704.0291 | Approaching the Heisenberg limit in an atom laser | We present experimental and theoretical results showing the improved beam
quality and reduced divergence of an atom laser produced by an optical Raman
transition, compared to one produced by an RF transition. We show that Raman
outcoupling can eliminate the diverging lens effect that the condensate has on
the outcoup... | physics.atom-ph cond-mat.other |
0704.0292 | A practical Seedless Infrared-Safe Cone jet algorithm | Current cone jet algorithms, widely used at hadron colliders, take event
particles as seeds in an iterative search for stable cones. A longstanding
infrared (IR) unsafety issue in such algorithms is often assumed to be solvable
by adding extra `midpoint' seeds, but actually is just postponed to one order
higher in th... | hep-ph |
0704.0293 | Isospin breaking in the yield of heavy meson pairs in e+e- annihilation
near threshold | We revisit the problem of interplay between the strong and the Coulomb
interaction in the charged-to-neutral yield ratio for $B {\bar B}$ and $D {\bar
D}$ pairs near their respective thresholds in $e^+e^-$ annihilation. We
consider here a realistic situation with a resonant interaction in the isospin
I=0 channel and ... | hep-ph |
0704.0294 | QED x QCD Resummation and Shower/ME Matching for LHC Physics | We present the theory of QED x QCD resummation and its interplay with
shower/matrix element matching in precision LHC physics scenarios. We
illustrate the theory using single heavy gauge boson production at hadron
colliders.
| hep-ph |
0704.0295 | On the number of topological types occurring in a parametrized family of
arrangements | Let ${\mathcal S}(\R)$ be an o-minimal structure over $\R$, $T \subset
\R^{k_1+k_2+\ell}$ a closed definable set, and $$ \displaylines{\pi_1:
\R^{k_1+k_2+\ell}\to \R^{k_1 + k_2}, \pi_2: \R^{k_1+k_2+\ell}\to \R^{\ell}, \
\pi_3: \R^{k_1 + k_2} \to \R^{k_2}} $$ the projection maps.
For any collection ${\mathcal A} = \... | math.CO math.GT |
0704.0296 | Generalized Twistor Transform And Dualities, With A New Description of
Particles With Spin, Beyond Free and Massless | A generalized twistor transform for spinning particles in 3+1 dimensions is
constructed that beautifully unifies many types of spinning systems by mapping
them to the same twistor, thus predicting an infinite set of duality relations
among spinning systems with different Hamiltonians. Usual 1T-physics is not
equipped... | hep-th |
0704.0297 | Remnant evolution after a carbon-oxygen white dwarf merger | We systematically explore the evolution of the merger of two carbon-oxygen
(CO) white dwarfs. The dynamical evolution of a 0.9 Msun + 0.6 Msun CO white
dwarf merger is followed by a three-dimensional SPH simulation. We use an
elaborate prescription in which artificial viscosity is essentially absent,
unless a shock i... | astro-ph |
0704.0298 | Direct Theorems in the Theory of Approximation of the Banach Space
Vectors by Entire Vectors of Exponential Type | For an arbitrary operator A on a Banach space X which is a generator of
C_0-group with certain growth condition at the infinity, the direct theorems on
connection between the smoothness degree of a vector $x\in X$ with respect to
the operator A, the order of convergence to zero of the best approximation of x
by expon... | math.FA math.SP |
0704.0299 | Parametrized Post-Newtonian Expansion of Chern-Simons Gravity | We investigate the weak-field, post-Newtonian expansion to the solution of
the field equations in Chern-Simons gravity with a perfect fluid source. In
particular, we study the mapping of this solution to the parameterized
post-Newtonian formalism to 1 PN order in the metric. We find that the PPN
parameters of Chern-S... | hep-th astro-ph gr-qc |
0704.0300 | Scaling of Resistance and Electron Mean Free Path of Single-Walled
Carbon Nanotubes | We present an experimental investigation on the scaling of resistance in
individual single walled carbon nanotube devices with channel lengths that vary
four orders of magnitude on the same sample. The electron mean free path is
obtained from the linear scaling of resistance with length at various
temperatures. The l... | cond-mat.mes-hall cond-mat.mtrl-sci |
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