December 2008 arXiv papers — page 39
Showing 3,801–3,900 of 5,096 papers
Marin-Slobodan Tomas, Zdravko Lenac
We consider the vacuum-field pressure on boundaries of a metal slab in the middle of a cavity with perfectly reflecting mirrors adopting the plasma model for the metal and paying special attention to the surface plasmon polariton contribution to the pressure. We demonstrate that, with increasing cavity length, the pressure on a thin (d<<λ_P) slab in this sys
C. Regenfus
The ArDM experiment, a 1 ton liquid argon TPC/Calorimeter, is designed for the detection of dark matter particles which can scatter off the spinless argon nuclei. These events producing a recoiling nucleus will be discerned by their light to charge ratio, as well as the time structure of the scintillation light. The experiment is presently under construction
Extremely faint high proper motion objects from SDSS stripe 82 - Optical classification spectroscopy of about 40 new objects
astro-phR. -D. Scholz, J. Storm, G. R. Knapp, H. Zinnecker
(abridged) Deep multi-epoch Sloan Digital Sky Survey data in a 275 square degrees area along the celestial equator (SDSS stripe 82 = S82) allowed us to search for extremely faint ($i>21$) objects with proper motions larger than 0.14 arcsec/yr. We classify 38 newly detected objects with low-resolution optical spectroscopy using FORS1 @ ESO VLT. All 22 previou
Could the Fermi-LAT detect gamma-rays from dark matter annihilation in the dwarf galaxies of the Local Group?
astro-phL. Pieri, A. Pizzella, E. M. Corsini, E. Dalla Bonta'
The detection of gamma-rays from dark matter (DM) annihilation is among the scientific goals of the Fermi Large Area Telescope (formerly known as GLAST) and Cherenkov telescopes. In this paper we investigate the existence of realistic chances of such a discovery selecting some nearby dwarf spheroidal galaxies (dSph) as a target. We study the detectability wi
J. M. Speight
Motivated by the sigma model limit of multicomponent Ginzburg-Landau theory, a version of the Faddeev-Skyrme model is considered in which the scalar field is coupled dynamically to a one-form field called the supercurrent. This coupled model is investigated in the general setting where physical space is an oriented Riemannian manifold and the target space is
Pulak Ranjan Giri
We show that the strength of non-commutativity could play a role in determining the boundary condition of a physical problem. As a toy model we consider the inverse square problem in non-commutative space. The scale invariance of the system is known to be explicitly broken by the scale of non-commutativity Θ. The resulting problem in non-commutative space is
L. V. Kulik, S. Dickmann, I. K. Drozdov, I. S. Zhuravlev
An antiphased magnetoplasma (MP) mode in a two-dimensional electron gas (2DEG) has been studied by means of inelastic light scattering (ILS) spectroscopy. Unlike the cophased MP mode it is purely quantum excitation which has no classic plasma analogue. It is found that zero momentum degeneracy for the antiphased and cophased modes predicted by the first-orde
Samuel A Meek, Horst Conrad, Gerard Meijer
A microstructured array of 1254 electrodes on a substrate has been configured to generate an array of local minima of electric field strength with a periodicity of 120 $μ$m about 25 $μ$m above the substrate. By applying sinusoidally varying potentials to the electrodes, these minima can be made to move smoothly along the array. Polar molecules in low-field s
Studying the continuum spectrum of the parsec scale jets by multi-frequency VLBI measurements
astro-phT. Savolainen, K. Wiik, E. Valtaoja, M. Tornikoski
Multi-frequency VLBI observations allow studies of the continuum spectrum in the different parts of the parsec scale jets of AGN, providing information on the physical properties of the plasma and magnetic fields in them. Since VLBI networks cannot be scaled, the range of spatial frequencies observed differs significantly between the different observing freq
Parallel hierarchical sampling: a practical multiple-chains sampler for Bayesian model selection
stat.COFabio Rigat
This paper introduces the parallel hierarchical sampler (PHS), a Markov chain Monte Carlo algorithm using several chains simultaneously. The connections between PHS and the parallel tempering (PT) algorithm are illustrated, convergence of PHS joint transition kernel is proved and and its practical advantages are emphasized. We illustrate the inferences obtai
Erik Woldhuis, Brian P. Tighe, Wim van Saarloos
The spot model has been developed by Bazant and co-workers to describe quasistatic granular flows. It assumes that granular flow is caused by the opposing flow of so-called spots of excess free volume, with spots moving along the slip lines of Mohr-Coulomb plasticity. The model is two-dimensional and has been successfully applied to a number of different geo
M. Reponen, T. Kessler, I. D. Moore, S. Rothe
A development program is underway at the IGISOL (Ion Guide Isotope Separator On-Line) facility, University of Jyvaskyla, to efficiently and selectively produce low-energy radioactive ion beams of silver isotopes and isomers, with a particular interest in N=Z 94Ag. A hot cavity ion source has been installed, based on the FEBIAD (Forced Electron Beam Induced A
M-J Strong, Sarah Whitehouse
The elements of the ring of bidegree (0,0) additive unstable operations in complex K-theory can be described explicitly as certain infinite sums of Adams operations. Here we show how to make sense of the same expressions for complex cobordism MU, thus identifying the "Adams subring" of the corresponding ring of cobordism operations. We prove that the
Michel Destrade, Ray W. Ogden, Giuseppe Saccomandi
We study the propagation of small amplitude waves superimposed on a large static deformation in a nonlinear viscoelastic material of differential type. We use bulk waves and surface waves to address the questions of dissipation and of material and geometric stability. In particular, the analysis provides bounds on the constitutive parameters and on the pre-d
Surface waves and surface stability for a pre-stretched, unconstrained, non-linearly elastic half-space
physics.class-phJ. G. Murphy, M. Destrade
An unconstrained, non-linearly elastic, semi-infinite solid is maintained in a state of large static plane strain. A power-law relation between the pre-stretches is assumed and it is shown that this assumption is well-motivated physically and is likely to describe the state of pre-stretch for a wide class of materials. A general class of strain-energy functi
Zahra Shomali, Malek Zareyan, Wolfgang Belzig
We investigate the Josephson current between two superconductors (S) which are connected through a diffusive magnetic junction with a complex structure (F$_{c}$). Using the quantum circuit theory, we obtain the phase diagram of 0 and $π$ Josephson couplings for F$_{c}$ being a IFI (insulator-ferromagnet-insulator) double barrier junction or a IFNFI structure
Andrew Hubery
We show that the cluster complex of an arbitrary hereditary artin algebra has the structure of an abstract simplicial polytope. In particular, the cluster-tilting objects form one equivalence class under mutation.
Junichiro Shiomi, Shigeo Maruyama
In this work, by means of molecular dynamics simulations, we consider mass transport of a water cluster inside a single-walled carbon nanotube (SWNT) with the diameter of about 1.4 nm. The influence of the non-equilibrium thermal environment on the confined water cluster has been investigated by imposing a longitudinal temperature gradient to the SWNT. It is
Franco Joos, Esther Buenzli, Hans Martin Schmid, Christian Thalmann
We present a method based on Mueller calculus to calibrate linear polarimetric observations. The key advantages of the proposed way of calibration are: (1) that it can be implemented in a data reduction pipeline, (2) that it is possible to do accurate polarimetry also for telescopes/instruments with polarimetric non-friendly architecture (e.g. Nasmyth instru
S. Afsar Abbas
Traditionally, the difference in binding energy from the experimental value with respect to the theoretical liquid-drop model value, has been seen as indication of independent-particle character along with magicity for particular number of protons and neutrons. We study this carefully to demonstrate that it actually indicates that the liquid-drop and the ind
Johan Öinert, Patrik Lundström
In order to simultaneously generalize matrix rings and group graded crossed products, we introduce category crossed products. For such algebras we describe the center and the commutant of the coefficient ring. We also investigate the connection between on the one hand maximal commutativity of the coefficient ring and on the other hand nonemptyness of interse
Ari J. Hietanen, Jarno Rantaharju, Kari Rummukainen, Kimmo Tuominen
An SU(2) gauge theory with two fermions transforming under the adjoint representation of the gauge group may appear conformal or almost conformal in the infrared. We use lattice simulations to study the spectrum of this theory and present results on the masses of several gauge singlet states as a function of the physical quark mass determined through the axi
V. V. Pipin, N. Seehafer
We revisit the possible turbulent sources of the solar dynamo. Studying axisymmetric mean-field dynamo models, we find that the large-scale poloidal magnetic field could be generated not only by the famous alpha effect, but also by the Omega x J and shear-current effects. The inclusion of these additional turbulent sources alleviates several of the known pro
Sven-S. Porst
The 2-categories of strict 2-groups and crossed modules are introduced and their 2-equivalence is made explicit.
Paolo Ferraris
Answer set programming (ASP) is a logic programming paradigm that can be used to solve complex combinatorial search problems. Aggregates are an ASP construct that plays an important role in many applications. Defining a satisfactory semantics of aggregates turned out to be a difficult problem, and in this paper we propose a new approach, based on an analogy
Effective pairing interaction in the two-dimensional Hubbard model within a spin rotationally invariant approach
cond-mat.str-elV. A. Apinyan, T. K. Kopec
We implement the rotationally-invariant formulation of the two-dimensional Hubbard model, with nearest-neighbors hopping $t$, which allows for the analytical study of the system in the low-energy limit. Both U(1) and SU(2) gauge transformations are used to factorize the charge and spin contributions to the original electron operator in terms of the correspon
Laura Tolos, Daniel Cabrera, Daniel Gamermann, Tetsuro Mizutani
We study the properties of strange and charm mesons in hot and dense matter within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected for the CBM experiment at FAIR/GSI. The in-medium solution at finite temperature accounts for Pauli blocking effects, mean-field binding on all the baryons involved,
I. Tsukerman, for ATLAS, CMS Collaborations
The discovery potential of Standard Model Higgs searches at the LHC at 14 TeV center-of-mass energy is reviewed. Decay channels such as $H\toγγ$, $H\to ZZ^{\star}\to 4\ell$, $H\to WW^{\star}$ and $H\to ττ$ are considered. Results are based on the most recent full GEANT-based simulations performed by the ATLAS and CMS experiments.
Michal Micuda, Miroslav Jezek, Miloslav Dusek, Jaromir Fiurasek
We experimentally demonstrate a programmable single-qubit quantum gate. This device applies a unitary phase shift operation to a data qubit with the value of the phase shift being fully determined by the state of a program qubit. Our linear optical implementation is based on the encoding of qubits into polarization states of single photons, two-photon interf
Dynamics of a quantum phase transition with decoherence: the quantum Ising chain in a static spin environment
quant-phLukasz Cincio, Jacek Dziarmaga, Jakub Meisner, Marek M. Rams
We consider a linear quench from the paramagnetic to ferromagnetic phase in the quantum Ising chain interacting with a static spin environment. Both decoherence from the environment and non-adiabaticity of the evolution near a critical point excite the system from the final ferromagnetic ground state. For weak decoherence and relatively fast quenches the exc
Adsorption and dissociation of O$_{2}$ at Be(0001): First-principles prediction of an energy barrier on the adiabatic potential energy surface
cond-mat.mtrl-sciPing Zhang, Bo Sun, Yu Yang
The adsorption and dissociation of O$_{2}$ molecules at the Be(0001) surface is studied by using density-functional theory within the generalized gradient approximation and a supercell approach. The physi- and chemisorbed molecular precursor states are identified to be along the parallel and vertical channels, respectively. It is shown that the HH-Z (see the
Robert Conte
We consider the anharmonic oscillator with an arbitrary-degree anharmonicity, a damping term and a forcing term, all coefficients being time-dependent: u" + g_1(x) u' + g_2(x) u + g_3(x) u^n + g_4(x) = 0, n real. Its physical applications range from the atomic Thomas-Fermi model to Emden gas dynamics equilibria, the Duffing oscillator and numerous dy
Konstantin V. Rerikh
We consider a dynamics of a generic birational plane map Φ_n: CP^2 \to CP^2, CP^2 -image of the birational mapping (inverse map is also rational)F_n : C^2 \to C^2 and its such important characteristic as the Arnold complexity C_A(k), which is proportional d(k)=deg(Φ_n^k)- a degree of k-iteration of the map Φ_n, on the basis on algebraic-geometrical propertie
Yiqiang Li, Zongzhu Lin
We study the canonical basis for the negative part of the quantum generalized Kac-Moody algebra associated to a symmetric Borcherds-Cartan matrix. The algebras associated to two different matrices satisfying certain conditions may coincide. We show that the canonical bases coincide provided that the algebras coincide. We also answer partially a question by L
Orbital reconstruction and two-dimensional electron gas at the LaAlO3/SrTiO3 interface
cond-mat.mtrl-sciM. Salluzzo, G. Ghiringhelli, J. C. Cezar, N. B. Brookes
Conventional two-dimensional electron gases are realized by engineering the interfaces between semiconducting compounds. In 2004, Ohtomo and Hwang discovered that an electron gas can be also realized at the interface between large gap insulators made of transition metal oxides [1]. This finding has generated considerable efforts to clarify the underlying mic
Bianchi type-I string cosmological model in the presence of a magnetic flux: exact and qualitative solutions
gr-qcBijan Saha, Victor Rikhvitsky, Mihai Visinescu
A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is investigated. The objective of this study is to generate solutions to the Einstein equations using a few tractable assumptions usually accepted in the literature. The analytical solutions are supplemented with numerical and qualitative analysis. In the frame
L. Harnau
Various properties of fluids consisting of platelike particles differ from the corresponding ones of fluids consisting of spherical particles because interactions between platelets depend on their mutual orientations. One of the main issues in this topic is to understand how structural properties of such fluids depend on factors such as the shape of the plat
W. Curdt, H. Tian, L. Teriaca, U. Schuehle
We study the emission of the hydrogen Lyman-a line in the quiet Sun, its center-to-limb variation (CLV), and its radiance distribution. We also compare quasi-simultaneous Ly-a and Ly-b line profiles. We used the high spectral and spatial resolution of the SUMER spectrometer and completed raster scans at various locations along the disk. For the first time, w
B. Betz, D. Henkel, D. H. Rischke
We present the results of deriving the Israel-Stewart equations of relativistic dissipative fluid dynamics from kinetic theory via Grad's 14-moment expansion. Working consistently to second order in the Knudsen number, these equations contain several new terms which are absent in previous treatments.
Vortex splitting and phase separating instabilities of coreless vortices in F=1 spinor Bose-Einstein condensates
cond-mat.otherM. Takahashi, V. Pietila, M. Mottonen, T. Mizushima
The low lying excitations of coreless vortex states in F = 1 spinor Bose-Einstein condensates (BECs) are theoretically investigated using the Gross-Pitaevskii and Bogoliubov-de Gennes equations. The spectra of the elementary excitations are calculated for different spin-spin interaction parameters and ratios of the number of particles in each sublevel. There
Kazuhiro Nakazawa, Craig L. Sarazin, Madoka Kawaharada, Takao Kitaguchi
Wide-band Suzaku data on the merging cluster Abell 3667 were examined for hard X-ray emission in excess to the known thermal component. Suzaku detected X-ray signals in the wide energy band from 0.5 to 40 keV. The hard X-ray (> 10 keV) flux observed by the HXD around the cluster center cannot be explained by a simple extension of the thermal emission with av
X. J. Lou
We classify the switching kinetics of ferroelectrics including both epitaxial/polycrystalline thin films and single-crystalline/ceramic bulks at various applied fields into four categories, depending on whether the depolarization field and/or the polarization reversal induced by the switching promotion effect between adjacent parts can be neglected. We show
Martin Kümmel, Jeremy Walsh, Norbert Pirzkal, Harald Kuntschner
The methods and techniques for the slitless spectroscopy software aXe, which was designed to reduce data from the various slitless spectroscopy modes of Hubble Space Telescope instruments, are described. aXe can treat slitless spectra from different instruments such as ACS, NICMOS and WFC3 through the use of a configuration file which contains all the instru
Alexander E. Shalyt-Margolin
This is a short analysis of the changes in the concept of entropy as applied to physics of the present-day and Early Universe. Of special interest is a leading role of such a notion as deformation of a physical theory. The relation to a symmetry of the corresponding theory is noted. As this work is not a survey, the relevant author's works are mainly con
Xiaoping Xu
In this paper, we use partial differential equations to find the decomposition of the polynomial algebra over the basic irreducible module of $E_7$ into a sum of irreducible submodules. Moreover, we obtain a combinatorial identity, saying that the dimensions of certain irreducible modules of $E_7$ are correlated by the binomial coefficients of fifty-five. Fu
Frederico Arroja
Models with extra dimensions have attracted much interest recently because they may provide the solution for long standing problems in physics. One interesting and very attractive idea is that our visible universe is confined to a four-dimensional hypersurface in a higher-dimensional spacetime. This membrane like universe was dubbed brane-world. The main goa
Søren Fournais, Maria Hoffmann-Ostenhof, Thomas Hoffmann-Ostenhof, Thomas Østergaard Sørensen
We study the regularity at the positions of the (fixed) nuclei of solutions to (non-relativistic) multiconfiguration equations (including Hartree--Fock) of Coulomb systems. We prove the following: Let {phi_1,...,phi_M} be any solution to the rank--M multiconfiguration equations for a molecule with L fixed nuclei at R_1,...,R_L in R^3. Then, for any j in {1,.
V. M. Kolomietz, S. V. Radionov
The general problem of dissipation in macroscopic large-amplitude collective motion and its relation to energy diffusion of intrinsic degrees of freedom of a nucleus is studied. By applying the cranking approach to the nuclear many body system, a set of coupled dynamical equations for the collective classical variables and the quantum mechanical occupancies
Thomas DeGrand, Yigal Shamir, Benjamin Svetitsky
We have performed numerical simulations of SU(3) gauge theory coupled to Nf=2 flavors of symmetric representation fermions. The fermions are discretized with the tadpole-improved clover action. Our simulations are done on lattices of length L=6, 8, and 12. In all simulation volumes we observe a crossover from a strongly coupled confined phase to a weak coupl
Ken-ichi Sekiguchi, Tomohiro Okamoto, Takanori Fujiwara
Magnetic translation symmetry on a finite periodic square lattice is investigated for an arbitrary uniform magnetic field in arbitrary dimensions. It can be used to classify eigenvectors of the Hamiltonian. The system can be converted to another system of half or lower dimensions. A higher dimensional generalization of Harper equation is obtained for tight-b
D. V. Dmitriev, V. Ya. Krivnov
The frustrated spin-1/2 chain with weakly anisotropic ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor exchanges is studied. We focus on the excitation spectrum and the low-temperature thermodynamics in the ferromagnetic region of the ground state phase diagram. It is shown that the excitation spectrum of the model is characterized
Weiwei Zhang, Ming Gong, Chuan-Feng Li, Guang-Can Guo
The binding energies of trions ($X^+$, $X^-$) and biexciton (XX) in self-assembled semiconductor quantum dots (QDs) are very sensitive to the geometry and chemical composition of the QDs, and are random from dots to dots. However, in this letter, we show through analytical and numerical methods that the transition energies of the exciton complexes in self-as
Ratna Koley
Warped braneworld scenario provides an alternative to the usual Kaluza-Klein compactification of extra dimensions through the so-called localization of fields. Randall-Sundrum type models do not directly prove, rather, assume that all standard model fields are localized to the TeV brane. I will provide the mechanism for addressing the problem and discuss the
S. W. Ham, S. K. OH
We find that, at the one-loop level, the spontaneous CP violation is possible in a supersymmetric standard model that has an extra chiral Higgs triplet with hypercharge Y=0. At the tree level, this triplet-extended supersymmetric standard model (TESSM) cannot have any reasonable parameter spaces for the spontaneous CP violation, because the experimental cons
Tadao Oda
This paper was submitted to the Oberwolfach Conference "Combinatorial Convexity and Algebraic Geometry", October 1997. Let $M={\mathbb Z}^r$. For convex lattice polytopes $P,P'$ in ${\mathbb R}^r$, when is $(M \cap P)+ (M \cap P') = M \cap (P + P')$? Without any additional condition, the equality obviously does not hold. When the pair $(M
R. A. Scheepmaker, H. J. G. L. M. Lamers, P. Anders, S. S. Larsen
Aims. We study the connection between spatially resolved star formation and young star clusters across the disc of M51. Methods. We combine star cluster data based on B, V, and I-band Hubble Space Telescope ACS imaging, together with new WFPC2 U-band photometry to derive ages, masses, and extinctions of 1580 resolved star clusters using SSP models. This data
Detection of Polarimetric Variations Associated with the Shortest Time-Scale Variability in S5 0716$ + $714
astro-phMahito Sasada, Makoto Uemura, Akira Arai, Yasushi Fukazawa
We present the result of near-infrared and optical observations of the BL Lac object S5 0716$ + $714 carried out by the KANATA telescope. S5 0716$ + $714 has both a long term high-amplitude variability and a short-term variability within a night. The shortest variability (microvariability) time-scale is important for understanding the geometry of jets and ma
The Belle Collaboration, I. Adachi
We report on a study of the branching fractions for the exclusive charmless semileptonic B decay modes B to pi+ l nu, B to pi0 l nu, B to rho+ l nu, B to rho0 l nu and B to omega l nu, using events tagged by fully reconstructing one of the B mesons in a hadronic decay mode. The obtained branching fractions are B(B to pi+ l nu) = (1.12 +- 0.18 +- 0.05) x 1E-4
Atomic collapse, Lorentz boosts, Klein scattering, and other quantum-relativistic phenomena in graphene
cond-mat.mes-hallAndrei Shytov, Mark Rudner, Nan Gu, Mikhail Katsnelson
Electrons in graphene, behaving as massless relativistic Dirac particles, provide a new perspective on the relation between condensed matter and high-energy physics. We discuss atomic collapse, a novel state of superheavy atoms stripped of their discrete energy levels, which are transformed into resonant states. Charge impurities in graphene provide a conven
Ewa Czuchry
This paper explores single field inflation models with a constant, but arbitrary speed of sound c_s, obtained by deforming the kinetic energy terms to a Dirac-Born-Infeld form. Allowing c_s<1 provides a simple parameterization of non-gaussianity. The dependence of inflationary observables on the parameter c_s is considered in the leading order slow roll appr
E. Meinrenken
We explain how to define the quantization of q-Hamiltonian SU(2)-spaces as push-forwards in twisted K-homology, and prove a `quantization commutes with reduction' theorem for this setting. As applications, we show how the Verlinde formulas for flat SU(2) or SO(3) bundles are obtained by localization in twisted K-homology.
Sumit R. Das, Gautam Mandal
We investigate the question of distinguishing between different microstates of the D1-D5 system (with charges Q_1 and Q_5), by scattering with an incoherent beam, composed of a supergravity probe, with central energy E_0 and width (ΔE). The scattering is studied in the dual CFT description in the orbifold limit for finite R, where R is the radius of the circ
Joshua J Adams, Gary J. Hill, Phillip J. MacQueen
We have used the visible integral-field replicable unit spectrograph prototype (VIRUS-P), a new integral field spectrograph, to study the spatially and spectrally resolved Lyman-alpha emission line structure in the radio galaxy B2 0902+34 at z=3.4. We observe a halo of Lyman-alpha emission with a velocity dispersion of 250 km/s extending to a radius of 50 kp
The Bean model of the critical state in a magnetically shielded superconductor filament
cond-mat.supr-conS. V. Yampolskii, Yu. A. Genenko, H. Rauh, A. V. Snezhko
We study the magnetization of a cylindrical type-II superconductor filament covered by a coaxial soft-magnet sheath and exposed to an applied transverse magnetic field. Examining penetration of magnetic flux into the superconductor core of the filament on the basis of the Bean model of the critical state, we find that the presence of a non-hysteretic magneti
Marina Avitabile, Giuseppe Jurman, Sandro Mattarei
Thin Lie algebras are Lie algebras L, graded over the positive integers, with all homogeneous components of dimension at most two, and satisfying a more stringent but natural narrowness condition modeled on an analogous one for pro-p groups. The two-dimensional homogeneous components of L, which include that of degree one, are named diamonds. Infinite-dimens
Burak Himmetoglu, Carlo R. Contaldi, Marco Peloso
We prove that the anisotropic inflationary background of the Ackerman-Carroll-Wise model, characterized by a fixed-norm vector field, is unstable. We found the instability by explicitly solving the linearized equations for the most general set of perturbations around this background, and by noticing that the solutions diverge close to horizon crossing. This
Anna Frebel
The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of the chemical evolution of the Galaxy. In particular, these stars allow us to study the formation and evolution of the elements and the involved nucleosynthesis processes. Metal-poor stars are the local equivalent of the high-redshift Universe, and t
Noam Soker, Adam Frankowski, Amit Kashi
We study four scenarios for the SCP 06F6 transient event that was announced recently. Some of these were previously briefly discussed as plausible models for SCP 06F6, in particular with the claimed detection of a z=0.143 cosmological redshift of a Swan spectrum of a carbon rich envelope. We adopt this value of z for extragalactic scenarios. We cannot rule o
S. S. Larsen
The initial cluster mass function (ICMF) in spiral galaxy discs is constrained and compared with data for old globular clusters and young clusters in starbursts. It is found that the observed ages and luminosities of the brightest clusters in spiral discs can be reproduced if the ICMF is a Schechter function with a cut-off mass (Mc) of a few times 10^5 Msun
Leonid Barenboim, Michael Elkin
The distributed (Delta + 1)-coloring problem is one of most fundamental and well-studied problems of Distributed Algorithms. Starting with the work of Cole and Vishkin in 86, there was a long line of gradually improving algorithms published. The current state-of-the-art running time is O(Delta log Delta + log^* n), due to Kuhn and Wattenhofer, PODC'06. L
V. Araujo, A. Bufetov
Large deviation rates are obtained for suspension flows over symbolic dynamical systems with a countable alphabet. The method is that of the first author and follows that of L.-S. Young. A corollary of the main results is a large deviation bound for the Teichmüller flow on the moduli space of abelian differentials, which extends earlier work of J. Athreya.
P. R. Johnson, E. Tiesinga, J. V. Porto, C. J. Williams
We show that there are effective three- and higher-body interactions generated by the two-body collisions of atoms confined in the lowest vibrational states of a 3D optical lattice. The collapse and revival dynamics of approximate coherent states loaded into a lattice are a particularly sensitive probe of these higher-body interactions; the visibility of int
Wilson Toussile, Elisabeth Gassiat
We propose a Model-Based Clustering (MBC) method combined with loci selection using multi-allelic loci genetic data. The loci selection problem is regarded as a model selection problem and models in competition are compared with the Bayesian Information Criterion (BIC). The resulting procedure selects the subset of clustering loci, the number of clusters, es
An Extension of the Permutation Group Enumeration Technique (Collapse of the Polynomial Hierarchy: $\mathbf{NP = P}$)
cs.CCJavaid Aslam
The distinguishing result of this paper is a $\mathbf{P}$-time enumerable partition of all the potential perfect matchings in a bipartite graph. This partition is a set of equivalence classes induced by the missing edges in the potential perfect matchings. We capture the behavior of these missing edges in a polynomially bounded representation of the exponent
Pierre-Emmanuel Caprace, Nicolas Monod
Let $Γ$ be an irreducible lattice in a product of n infinite irreducible complete Kac-Moody groups of simply laced type over finite fields. We show that if n is at least 3, then each Kac-Moody groups is in fact a simple algebraic group over a local field and $Γ$ is an arithmetic lattice. This relies on the following alternative which is satisfied by any irre
Mary Rees
We produce arbitrarily large equivalence classes of matings with the aeroplane polynomial. These are obtained by a slight generalisation of the technique of proof of a similar result for Wittner captures.
Andreas Tziolas, Anzhong Wang, Zhong Chao Wu
Colliding branes without $Z_{2}$ symmetry and the formation of spacetime singularities in string theory are studied. After developing the general formulas to describe such events, we study a particular class of exact solutions first in the 5-dimensional effective theory, and then lift it to the 10-dimensional spacetime. In general, the 5-dimensional spacetim
John H. Schwarz
The first lecture gives a colloquium-level overview of string theory and M-theory. The second lecture surveys various attempts to construct a viable model of particle physics. A recently proposed approach, based on F-theory, is emphasized.
Asymptotic analysis of a size-structured cannibalism model with infinite dimensional environmental feedback
math.APJozsef Z. Farkas, Thomas C. Hagen
In this work we consider a size-structured cannibalism model with the model ingredients (fertility, growth, and mortality rate) depending on size (ranging over an infinite domain) and on a general function of the standing population (environmental feedback). Our focus is on the asymptotic behavior of the system, in particular on the effect of cannibalism on
Jozsef Z. Farkas, Thomas C. Hagen
In the present paper we analyze the linear stability of a hierarchical size-structured population model where the vital rates (mortality, fertility and growth rate) depend both on size and a general functional of the population density ("environment"). We derive regularity properties of the governing linear semigroup, implying that linear stability is govern
Matrix elements of SU(6) generators for baryons with arbitrary $N_c$ quarks in mixed symmetric states $[N_c-1,1]$
hep-phN. Matagne, Fl. Stancu
We derive general analytic formulae for the matrix elements of the SU(6) generators for mixed symmetric $[N_c-1,1]$ spin-flavor states with an arbitrary number $N_c$ of quarks. They are relevant for baryon spectroscopy in the $1/N_c$ expansion method applied to light baryons and can be used to study excited states. In this way previous work on non-strange ba
Jozsef Z. Farkas, Darren Green, Peter Hinow
Motivated by structured parasite populations in aquaculture we consider a class of size-structured population models, where individuals may be recruited into the population with distributed states at birth. The mathematical model which describes the evolution of such a population is a first-order nonlinear partial integro-differential equation of hyperbolic
Evgenii I. Khukhro, Anton A. Klyachko, Natalia Yu. Makarenko, Yulia B. Melnikova
If an outer (multilinear) commutator identity holds in a large subgroup of a group, then it holds also in a large characteristic subgroup. Similar assertions are valid for algebras and their ideals or subspaces. Varying the meaning of the word "large", we obtain many interesting facts. These results cannot be extended to arbitrary (non-multilinear) i
Improved time-resolved magneto-optical Kerr effect technique and dynamic magnetization reversal mechanism of perpendicularly magnetized $L1_{\mathrm{0}}$ FePt films
cond-mat.str-elX. D. Liu, Z. Xu, R. X. Gao, Z. F. Chen
The dynamic coercivity cannot be measured rigorously by the conventional time-resolved magneto-optical Kerr effect technique because the irreversible deviation of the transient magnetization is accumulated. In order to remove the accumulation effect, the alternating magnetic field is employed and synchronized with the femtosecond laser pulse. Since the sampl
Efstratios Tsatis
We study monotonic quantities in the context of combined geometric flows. In particular, focusing on Ricci solitons as the ambient space, we consider solutions of the heat type equation integrated over embedded submanifolds evolving by mean curvature flow and we study their monotonicity properties. This is part of an ongoing project with Magni and Mantegazza
Semileptonic $D_{q}\to K_{1}\ell ν$ and nonleptonic $D\to K_1 π$ decays in three--point QCD sum rules and factorization approach
hep-phR. Khosravi, K. Azizi, N. Ghahramany
We analyze the semileptonic $D_{q}\to K_1 \ellν$ transition with $q=u, d, s$, in the framework of the three--point QCD sum rules and the nonleptonic $D\to K_1 π$ decay within the QCD factorization approach. We study $D_{q}$ to $K_1(1270)$ and $K_1(1400)$ transition form factors by separating the mixture of the $K_1(1270)$ and $K_1(1400)$ states. Using the tr
Teresa Hui-Ching Lu, Kishore Ananda, Chris Clarkson, Roy Maartens
We investigate the spectrum of vector modes today which is generated at second order by density perturbations. The vector mode background that is generated by structure formation is small but in principle it contributes to the integrated Sachs-Wolfe effect, to redshift-space distortions and to weak lensing. We recover, clarify and extend previous results, an
Position and frequency shifts induced by massive modes of the gravitational wave background in alternative gravity
gr-qcS. Bellucci, S. Capozziello, M. De Laurentis, V. Faraoni
Alternative theories of gravity predict the presence of massive scalar, vector, and tensor gravitational wave modes in addition to the standard massless spin~2 graviton of general relativity. The deflection and frequency shift effects on light from distant sources propagating through a stochastic background of gravitational waves, containing such modes, diff
Omid Amini, Louis Esperet, Jan van den Heuvel
In this paper we introduce the notion of $Σ$-colouring of a graph $G$: For given subsets $Σ(v)$ of neighbours of $v$, for every $v\in V(G)$, this is a proper colouring of the vertices of $G$ such that, in addition, vertices that appear together in some $Σ(v)$ receive different colours. This concept generalises the notion of colouring the square of graphs and
I. L. Zhogin
It is shown that modified gravity theories with a Lagrangian composed of the three quadratic invariants of the Riemann curvature tensor are not appropriate. The field equations are either incompatible and/or irregular [like f(R)-gravities], or, if compatible, lead to the linear instability of polarizations relating to the Weyl tensor. A more relevant modific
Craig J. Hogan, Mark G. Jackson
Using Matrix Theory as a concrete example of a fundamental holographic theory, we show that the emergent macroscopic spacetime displays a new macroscopic quantum structure, holographic geometry, and a new observable phenomenon, holographic noise, with phenomenology similar to that previously derived on the basis of a quasi-monochromatic wave theory. Traces o
Jae-Weon Lee, Sooil Lim
Many problems of cold dark matter models such as the cusp problem and the missing satellite problem can be alleviated, if galactic halo dark matter particles are ultra-light scalar particles and in Bose-Einstein condensate (BEC), thanks to a characteristic length scale of the particles. We show that this finite length scale of the dark matter can also explai
J. Aichelin, J. Schaffner-Bielich
The present status of the efforts to determine the nuclear equation of state from results of heavy ion reactions and from astrophysical observations is reviewed
B. Baykant Alagoz
In the paper, region based stereo matching algorithms are developed for extraction depth information from two color stereo image pair. A filter eliminating unreliable disparity estimation was used for increasing reliability of the disparity map. Obtained results by algorithms were represented and compared.
Oliver Gray
Aiming at a complete classification of unitary N=2 minimal models (where the assumption of space-time supersymmetry has been dropped), it is shown that each modular invariant candidate of a partition function for such a theory is indeed the partition function of a minimal model. A family of models constructed via orbifoldings of either the diagonal model or
Yosuke Imamura, Shuichi Yokoyama
We investigate a class of N=4 quiver Chern-Simons theories and their gravity duals. We define the group of fractional D3-brane charges in a type IIB brane setup with taking account of D3-brane creation due to Hanany-Witten effect, and confirm that it agrees with the 3-cycle homology of the dual geometry, which describes the charges of fractional M2-branes, M
Cosimo Bambi, Katherine Freese
We consider the possibility that astrophysical Black Holes (BHs) can violate the Kerr bound; i.e., they can have angular momentum greater than BH mass, $J > M$. We discuss implications on the BH apparent shape. Even if the bound is violated by a small amount, the shadow cast by the BH changes significantly (it is $\sim$ an order of magnitude smaller) from th
Scott N. Armstrong
We generalize the Donsker-Varadhan minimax formula for the principal eigenvalue of a uniformly elliptic operator in nondivergence form to the first principal half-eigenvalue of a fully nonlinear operator which is concave (or convex) and positively homogeneous. Examples of such operators include the Hamilon-Jacobi-Bellman operator and the Pucci extremal opera
Cyril Houdayer
We show that for any type ${\rm III_1}$ free Araki-Woods factor $\mathcal{M} = \Gamma(H_\R, U_t)"$ associated with an orthogonal representation $(U_t)$ of $\R$ on a separable real Hilbert space $H_\R$, the continuous core $M = \mathcal{M} \rtimes_\sigma \R$ is a semisolid ${\rm II_\infty}$ factor, i.e. for any non-zero finite projection $q \in M$, the ${\rm
Charles Rezk
We give a shorter proof of Lemma 1.9 from Goodwillie, "Calculus III", which is the key step in proving that the construction P_nF gives an n-excisive functor.