December 2008 arXiv papers — page 19

D. Ebert, R. N. Faustov, V. O. Galkin

The relativistic model of the ground state and excited heavy tetraquarks with hidden bottom is formulated within the diquark-antidiquark picture. The diquark structure is taken into account by calculating the diquark-gluon vertex in terms of the diquark wave functions. Predictions for the masses of bottom counterparts to the charm tetraquark candidates are g

Yusuke Wakabayashi, Naoko Takubo, Kenjiro Miyano, Hiroshi Sawa

Structural study on the photo-switching system Pr{0.55}(Ca{1-y}Sr y){0.45}MnO3 thin films on perovskite (011) substrate has been made with synchrotron radiation diffraction experiment. The insulating phase of y=0.20 sample was found to be an antiferro-orbital ordered phase with large lattice distortion and the ferromagnetic metallic phase of y=0.40 film show

Tomohiro Fukaya

We investigate the fixed point property of the group actions on a coarse space and its Higson corona. We deduce the coarse version of Brouwer's fixed point theorem.

Sunandan Gangopadhyay, Frederik G Scholtz

We formulate the coherent state path integral on a two dimensional noncommutative plane using the fact that noncommuative quantum mechanics can be viewed as a quantum system on the Hilbert space of Hilbert-Schmidt operators acting on noncommutative configuration space. The propagation kernel for the free particle shows ultra-violet cutoff which agrees with t

Benoit Estienne

The second $\mathbb{Z}_{3}$ parafermionic conformal theories are associated with the coset construction $\frac{SU(2)_{k}\times SU(2)_{4}}{SU(2)_{k+4}} $. Solid-on-solid integrable lattice models obtained by fusion of the model based on level-1 representation of the affine algebra $B_1^{(1)}$ have a critical point described by these conformal theories. Explic

Carlos T. Simpson

Given a vector bundle with integrable connection $(V,\nabla)$ on a curve, if $V$ is not itself semistable as a vector bundle then we can iterate a construction involving modification by the destabilizing subobject to obtain a Hodge-like filtration $F^p$ which satisfies Griffiths transversality. The associated graded Higgs bundle is the limit of $(V,t\nabla)$

R. Sharma, S. Karmakar, S. Mukherjee

Bound states of complex scalar fields (boson stars) have long been proposed as possible candidates for the dark matter in the universe. Considerable work has already been done to study various aspects of boson stars. In the present work, assuming a particular anisotropic matter distribution, we solve the Einstein-Klein-Gordon equations with a cosmological co

K. Jayasree, P. Ranjith, Madan Rao, P. B. Sunil Kumar

We study the equilibrium conformations of a grafted polyelectrolyte (PE) in the presence of explicit counterions (CI) using Monte Carlo simulations. The interplay between attractive Lennard-Jones interactions (parametrized by epsilon), and electrostatics (parametrized by A = q^2l_B/a, where q =counterion valency, l_B = Bjerrum length and a = monomer diameter

George Kirczenow, Paul G. Piva, Robert A. Wolkow

We report on the synthesis, scanning tunneling microscopy (STM) and theoretical modeling of the electrostatic and transport properties of one-dimensional organic heterostructures consisting of contiguous lines of CF3- and OCH3-substituted styrene molecules on silicon. The electrostatic fields emanating from these polar molecules are found, under appropriate

David E. Reynolds

We develop a renormalization group (RG) procedure that includes important system-specific features. The key ingredient is to systematize the coarse graining procedure that generates the RG flow. The coarse graining technology comes from control and operator theoretic model reduction. The resulting "generalized" RG is a consistent generalization of th

Sang Min Lee, Hai-Woong Lee

Based on the complementarity relation between entanglement of a composite system and the purity of a subsystem, we propose a simple method to measure the amount of entanglement. The method can be applied to a bipartite system in a pure state of any arbitrary dimension. It requires only single qudit rotations and straightforward probability measurements perfo

L. Harvey-Smith, B. M. Gaensler, C. -Y. Ng, A. J Green

Radio continuum emission from the supernova remnant G296.5+10.0 was observed using the Australia Telescope Compact Array. Using a 104 MHz bandwidth split into 13 x 8 MHz spectral channels, it was possible to produce a pixel-by-pixel image of Rotation Measure (RM) across the entire remnant. A lack of correlation between RM and X-ray surface brightness reveals

Travis Kopp

This paper was inspired by work by T. Peternell, M. Schneider and A.J. Sommese on the Kodaira dimension of subvarieties. In it I find a relation between the Kodaira-Iitaka dimension of a divisor on a normal variety and that of related divisors on an irreducible normal subvariety of codimension one. The main result may be stated in a simplified form as: For $

M. J. Luo, Q. Y. Liu

The Type I, II and hybrid (I+II) seesaw mechanism, which explain why neutrinos are especially light, are consequences of the left-right symmetric model (LRSM). They can be classified by the ranges of parameters of LRSM. We show that a nearly cancellation in general Type-(I+II) seesaw is more natural than other types of seesaw in the LRSM if we consider their

Xinping Xu

We consider coherent exciton transport modeled by continuous-time quantum walks (CTQWs) on long-range interacting cycles (LRICs), which are constructed by connecting all the two nodes of distance $m$ in the cycle graph. LRIC has a symmetric structure and can be regarded as the extensions of the cycle graph (nearest-neighboring lattice). For small values of $

Hiroyuki Hirashita, Huirong Yan

We investigate shattering and coagulation of dust grains in turbulent interstellar medium (ISM). The typical velocity of dust grain as a function of grain size has been calculated for various ISM phases based on a theory of grain dynamics in compressible magnetohydrodynamic turbulence. In this paper, we develop a scheme of grain shattering and coagulation an

M. Hilke

Anderson localization was discovered 50 years ago to describe the propagation of electrons in the presence of disorder. The main prediction back then, was the existence of disorder induced localized states, which do not conduct electricity. Many years later it turns out, that the concept of Anderson localization is much more general and applies to almost any

Włodzimierz Domański, Andrew N. Norris

Weakly nonlinear plane waves are considered in hyperelastic crystals. Evolution equations are derived at a quadratically nonlinear level for the amplitudes of quasi-longitudinal and quasi-transverse waves propagating in arbitrary anisotropic media. The form of the equations obtained depends upon the direction of propagation relative to the crystal axes. A si

E. de la Fuente, A. Porras, J. M. C. Grave, M. S. N. Kumar

We present the results of a morphological study performed to a sample of Ultracompact (UC) HII regions with Extended Emission (EE) using Spitzer--IRAC imagery and 3.6 cm VLA conf. D radio-continuum (RC) maps. Some examples of the comparison between maps and images are presented. Usually there is an IR point source counterpart to the peak(s) of RC emission, a

Ya-Wen Tang, Paul T. P. Ho, Josep Miquel Girart, Ramprasad Rao

We report high angular resolution (3") Submillimeter Array (SMA) observations of the molecular cloud associated with the Ultra-Compact HII region G5.89-0.39. Imaged dust continuum emission at 870 micron reveals significant linear polarization. The position angles (PAs) of the polarization vary enormously but smoothly in a region of 2x10^4 AU. Based on th

R. Hazrat

Let A be an Azumaya algebra of constant rank n^2 over a Hensel pair (R,I) where R is a semilocal ring with n invertible in R. Then the reduced Whitehead group SK(A) coincides with its reduction SK(A/IA).

Gia Dvali, Oriol Pujolas

Unitarity implies that the evaporation of microscopic quasi-classical black holes cannot be universal in different particle species. This creates a puzzle, since it conflicts with the thermal nature of quasi-classical black holes, according to which all the species should see the same horizon and be produced with the same Hawking temperatures. We resolve thi

Kody J. H. Law, P. G. Kevrekidis, Tristram J. Alexander, Wieslaw Krolikowski

We show that double-charge discrete optical vortices may be completely stable in hexagonal photonic lattices where single-charge vortices always exhibit dynamical instabilities. Even when unstable the double-charge vortices typically have a much weaker instability than the single-charge vortices, and thus their breakup occurs at longer propagation distances.

R. Aldrovandi, J. G. Pereira

The main consequences of de Sitter Special Relativity to the Standard Cosmological Model of Physical Cosmology are examined. The cosmological constant Lambda appears, in this theory, as a manifestation of the proper conformal current, which must be added to the usual energy-momentum density. As that conformal current itself vanishes in absence of sources, La

Michael J. Longo

In this article I extend an earlier study of spiral galaxies in the Sloan Digital Sky Survey (SDSS) to investigate whether the universe has an overall handedness. A preference for spiral galaxies in one sector of the sky to be left-handed or right-handed spirals would indicate a parity-violating asymmetry in the overall universe and a preferred axis. The pre

Henry Towsner

Kreisel has observed that the termination proof for Hilbert's epsilon-substitution method bears a resemblance to the priority arguments used in recursion theory. We make this precise by proving the termination using a framework for priority arguments due to Lerman and Lempp.

Ian Balitsky, Giovanni A. Chirilli

Using the requirement of Möbius invariance of ${\cal N}$=4 SYM amplitudes in the Regge limit we restore the conformal NLO BFKL kernel out of the eigenvalues known from the forward NLO BFKL result.

Marcelo A. Alvarez, Michael T. Busha, Tom Abel, Risa H. Wechsler

We present results of combined N-body and three-dimensional reionization calculations to determine the relationship between reionization history and local environment in a volume 1 Gpc/h across and a resolution of about 1 Mpc. We resolve the formation of about 2x10^6 halos of mass greater than ~10^12 Msun at z=0, allowing us to determine the relationship bet

J. D. Silverman, K. Kovac, C. Knobel, S. Lilly

The impact of environment on AGN activity up to z~1 is assessed by utilizing a mass-selected sample of galaxies from the 10k catalog of the zCOSMOS spectroscopic redshift survey. We identify 147 AGN by their X-ray emission as detected by XMM-Newton from a parent sample of 7234 galaxies. We measure the fraction of galaxies with stellar mass M_*>2.5x10^10 Msun

Marco Baumgartl, Simon Wood

We investigate the one-parameter Calabi-Yau models and identify families of D5-branes which are associated to lines embedded in these manifolds. The moduli spaces are given by sets of Riemann curves, which form a web whose intersection points are described by permutation branes. We arrive at a geometric interpretation for bulk-boundary correlators as holomor

Najib Mahdou, Mohammed Tamekkante

In this paper, we study the resolving of $\mathcal{SGP}(-)$ and $\mathcal{SGF}(-)$, the classes of all strongly Gorenstein projective and flat modules respectively, over a direct product of commutative rings.

Stephen Curran

We extend the notion of quantum exchangeability, introduced by Köstler and Speicher in arXiv:0807.0677, to sequences (ρ_1,ρ_2,...c) of homomorphisms from an algebra C into a noncommutative probability space (A,ϕ), and prove a free de Finetti theorem: an infinite quantum exchangeable sequence (ρ_1,ρ_2,...c) is freely independent and identically distributed wi

Dmytro Gavinsky

We define a new model of quantum learning that we call Predictive Quantum (PQ). This is a quantum analogue of PAC, where during the testing phase the student is only required to answer a polynomial number of testing queries. We demonstrate a relational concept class that is efficiently learnable in PQ, while in any "reasonable" classical model exponential am

C. Reichhardt, C. J. Olson Reichhardt

We provide evidence that plastic depinning falls into the same class of phenomena as the random organization which was recently studied in periodically driven particle systems [L. Corte et al., Nature Phys. 4, 420 (2008)]. In the plastic flow system, the pinned regime corresponds to the quiescent state and the moving state corresponds to the fluctuating stat

Yin-Zhe Ma, Xin Zhang

In this paper, we revisit brane inflation models with the WMAP five-year results. The WMAP five-year data favor a red-tilted power spectrum of primordial fluctuations at the level of two standard deviations, which is the same as the WMAP three-year result qualitatively, but quantitatively the spectral index is slightly greater than the three-year value. This

Andreas Luscher, Andreas Laeuchli

We study the field dependence of the antiferromagnetic spin-1/2 Heisenberg model on the square lattice by means of exact diagonalizations. In a first part, we calculate the spin-wave velocity, the spin-stiffness, and the magnetic susceptibility and thus determine the microscopic parameters of the low-energy long-wavelength description. In a second part, we p

Abouzeid M. Shalaby

Very recently, the Lee-Wick standard model has been introduced as a non-SUSY extension of the Standard model which solves the Hierarchy problem. In this model, each field kinetic term attains a higher derivative term. Like any Lee-Wick theory, this model suffers from existence of Ghost states. In this work, we consider a prototype scalar field theory with it

Long Dang, Massimo Boninsegni, Lode Pollet

We use quantum Monte Carlo simulations to study the phase diagram of hard-core bosons with short-ranged {\it attractive} interactions, in the presence of uniform diagonal disorder. It is shown that moderate disorder stabilizes a glassy superfluid phase in a range of values of the attractive interaction for which the system is a Mott insulator, in the absence

D. M. Worrall

Jet physics is again flourishing as a result of Chandra's ability to resolve high-energy emission from the radio-emitting structures of active galaxies and separate it from the X-ray-emitting thermal environments of the jets. These enhanced capabilities have coincided with an increasing interest in the link between the growth of super-massive black holes and

Petre Birtea, Ioan Casu, Tudor S. Ratiu, Murat Turhan

The stability for all generic equilibria of the Lie-Poisson dynamics of the $\mathfrak{so}(4)$ rigid body dynamics is completely determined. It is shown that for the generalized rigid body certain Cartan subalgebras (called of coordinate type) of $\mathfrak{so}(n)$ are equilibrium points for the rigid body dynamics. In the case of $\mathfrak{so}(4)$ there ar

J. R. Fergusson, E. P. S. Shellard

We present a set of formalisms for comparing, evolving and constraining primordial non-Gaussian models through the CMB bispectrum. We describe improved methods for efficient computation of the full CMB bispectrum for any general (non-separable) primordial bispectrum, incorporating a flat sky approximation and a new cubic interpolation. We review all the prim

Steven Furlanetto

The radiation background above the ionization edge of HeII varies strongly during and after helium reionization, because the attenuation length of such photons is relatively short (<40 Mpc) and because the ionizing sources (quasars) are rare. Here we construct analytic and Monte Carlo models to examine these fluctuations, including, for the first time, those

Sergey N. Solodukhin

In this note we prove that the volume of a causal diamond associated with an inertial observer in asymptotically de Sitter 4-dimensional space-time is monotonically increasing function of cosmological time. The asymptotic value of the volume is that of in maximally symmetric de Sitter space-time. The monotonic property of the volume is checked in two cases:

Edward L. Green, Eduardo do N. Marcos

The relationship between an algebra and its associated monomial algebra is investigated when at least one of the algebras is $d$-Koszul. It is shown that an algebra which has a reduced \grb basis that is composed of homogeneous elements of degree $d$ is $d$-Koszul if and only if its associated monomial algebra is $d$-Koszul. The class of 2-$d$-determined alg

Roshan Foadi, Mads T. Frandsen, Francesco Sannino

Dark Matter candidates are natural in Technicolor theories. We introduce a general framework allowing to predict signals of Technicolor Dark Matter at colliders and set constraints from earth based experiments such as CDMS and XENON. We show that the associate production of the composite Higgs can lead to relevant signals at the Large Hadron Collider.

Olivier Leveque, Christophe Vignat, Melda Yuksel

In this work, we investigate the diversity-multiplexing tradeoff (DMT) of the multiple-antenna (MIMO) static half-duplex relay channel. A general expression is derived for the DMT upper bound, which can be achieved by a compress-and-forward protocol at the relay, under certain assumptions. The DMT expression is given as the solution of a minimization problem

CDF Collaboration, T. Aaltonen

We report on the first search for top-quark production via flavor-changing neutral-current (FCNC) interactions in the non-standard-model process u(c)+g -> t using ppbar collision data collected by the CDF II detector. The data set corresponds to an integrated luminosity of 2.2/fb. The candidate events feature the signature of semileptonic top-quark decays an

Francesco Bigazzi, Aldo L. Cotrone, Angel Paredes, Alfonso V. Ramallo

We present a fully backreacted D3-D7 supergravity solution dual to the Klebanov-Strassler cascading gauge theory coupled to a large number of massive dynamical flavors in the Veneziano limit. The mass of the flavors can be larger or smaller than the dynamically generated scale. The solution is always regular at the origin of the radial coordinate and as such

De-Chang Dai, Dejan Stojkovic

Unparticle degrees of freedom, no matter how weakly coupled to the standard model particles, must affect the evolution of a black hole, which thermally decays into all available degrees of freedom. We develop a method for calculating the grey-body factors for scalar unparticles for 3+1 and higher dimensional black holes. We find that the power emitted in unp

Ann-Marie Madigan, Yuri Levin, Clovis Hopman

We identify a new secular instability of eccentric stellar disks around supermassive black holes. We show that retrograde precession of the stellar orbits, due to the presence of a stellar cusp, induces coherent torques that amplify deviations of individual orbital eccentricities from the average, and thus drive all eccentricities away from their initial val

Luca Carlevaro, Dan Israel, Marios Petropoulos

We consider heterotic string theory on Eguchi-Hanson space, as a local model of a resolved A_1 singularity in a six-dimensional flux compactification, with an Abelian gauge bundle turned on and non-zero torsion. We show that in a suitable double scaling limit, that isolates the physics near the non-vanishing two-cycle, a worldsheet conformal field theory des

Adam B. Hopkins, Frank H. Stillinger, Salvatore Torquato

Elementary smooth functions (beyond contact) are employed to construct pair correlation functions that mimic jammed disordered sphere packings. Using the g2-invariant optimization method of Torquato and Stillinger [J. Phys. Chem. B 106, 8354, 2002], parameters in these functions are optimized under necessary realizability conditions to maximize the packing f

N. R. Cooper, Ady Stern

We show that non-abelian quantum Hall states can be identified by experimental measurements of the temperature-dependence of either the electrochemical potential or the orbital magnetization. The predicted signals of non-abelian statistics are within experimental resolution, and can be clearly distinguished from other contributions under realistic circumstan

Cedric Delaunay, Patrick J. Fox, Gilad Perez

Recent results from PAMELA and ATIC hint that O(TeV) dark matter (DM) is annihilating, in our galactic neighborhood, predominantly to leptons. The annihilation rate is much larger now than during freeze-out, one possible explanation of this is a low-velocity enhancement of the annihilation cross section. In a model independent fashion, we show that in this c

U. Krey

In an informal way, a number of thoughts on the financial crisis 2008 are presented from a physicist&#39;s viewpoint, considering the problem as a nonergodicity transition of a spin-glass type of system. Some tentative suggestions concerning the way out of the crisis are also discussed, concerning Keynesian &#34;deficit spending&#34; methods, tax reductions,

Mihaela Pilca

On a Kähler spin manifold Kählerian twistor spinors are a natural analogue of twistor spinors on Riemannian spin manifolds. They are defined as sections in the kernel of a first order differential operator adapted to the Kähler structure, called Kählerian twistor (Penrose) operator. We study Kählerian twistor spinors and give a complete description of compac

Olivier Aj Bardou, Noufel Frikha, G. Pagès

Value-at-Risk (VaR) and Conditional Value-at-Risk (CVaR) are two risk measures which are widely used in the practice of risk management. This paper deals with the problem of computing both VaR and CVaR using stochastic approximation (with decreasing steps): we propose a first Robbins-Monro procedure based on Rockaffelar-Uryasev&#39;s identity for the CVaR. T

Nils Ovrelid, Sophia Vassiliadou

We discuss various known generalizations of the classical Hartogs&#39; extension theorem on Stein spaces with arbitrary singularities and present an analytic proof based on d-bar methods.

Abhishek Agarwal, Niklas Beisert, Tristan McLoughlin

We investigate the scattering matrix in mass-deformed N>=4 Chern-Simons models including as special cases the BLG and ABJM theories of multiple M2 branes. Curiously the structure of this scattering matrix in three spacetime dimensions is equivalent to (a) the two-dimensional worldsheet matrix found in the context of AdS/CFT integrability and (b) the R-matrix

Hyun Min Lee

We review on a recent construction of the on-shell supersymmetric brane action for the codimension-two branes with nonzero tension in the flux compactification of a 6D chiral gauged supergravity. On dimesionally reducing on 4D gauged supergravity for a new supersymmetric unwarped background with conical branes, we consider the modulus stabilization for deter

N. J. Upadhyay, N. G. Kelkar, B. K. Jain

The p + 6Li --> eta + 7Be reaction has been investigated with an emphasis on the eta meson and 7Be interaction in the final state. Considering the 6Li and 7Be nuclei to be alpha-d and alpha-3He clusters respectively, the reaction is modelled to proceed via the p + d [alpha] --> 3He [α] + eta reaction with the alpha remaining a spectator. The eta meson intera

Johan Aberg, Graeme Mitchison

Recently it has been shown that cumulants significantly simplify the analysis of multipartite weak measurements. Here we consider the mathematical structure that underlies this, and find that it can be formulated in terms of what we call the moment algebra. Apart from resulting in simpler proofs, the flexibility of this structure allows generalizations of th

T. Takahashi, T. Kishishita, Y. Uchiyama, T. Tanaka

We report on the results from Suzaku broadband X-ray observations of the galactic binary source LS5039. The Suzaku data, which have continuous coverage of more than one orbital period, show strong modulation of the X-ray emission at the orbital period of this TeV gamma-ray emitting system.The X-ray emission shows a minimum at orbital phase ~ 0.1, close to th

Tomoyuki Arakawa, Peter Fiebig

We study the restricted Verma modules of an affine Kac-Moody algebra at the critical level with special emphasis on their Jordan-H&#34;older multiplicities. The Feigin-Frenkel conjecture gives a formula for these multiplicities that involves the periodic Kazhdan-Lusztig polynomials. We prove this conjecture for all subgeneric blocks and for the case of anti-

Erwan Brugalle, Grigory Mikhalkin

In a previous paper, we announced a formula to compute Gromov-Witten and Welschinger invariants of some toric varieties, in terms of combinatorial objects called floor diagrams. We give here detailed proofs in the tropical geometry framework, in the case when the ambient variety is a complex surface, and give some examples of computations using floor diagram

Kim K. Nilsson, Christian Tapken, Palle Moeller, Wolfram Freudling

Context: Narrow-band surveys for Ly-alpha emitters (LAEs) is a powerful tool in detecting high, and very high, redshift galaxies. Even though samples are growing at redshifts z = 3 - 6, the nature of these galaxies is still poorly known. Aims: To study the properties of z = 2.25 LAEs and compare those with the properties of z > 3 LAEs. Methods: We present na

Jianguo Cao, Xiaoyang Chen

Theorem A. Let $M^n$ denote a closed Riemannian manifold with nonpositive sectional curvature and let $\tilde M^n$ be the universal cover of $M^n$ with the lifted metric. Suppose that the universal cover $\tilde M^n$ contains no totally geodesic embedded Euclidean plane $\mathbb{R}^2$ (i.e., $M^n$ is a visibility manifold). Then Gromov&#39;s simplicial volum

Eckart Viehweg

We discuss several numerical conditions for families of projective varieties or variations of Hodge structures.

G. Vianello, D. Götz, S. Mereghetti

We present a catalogue with the properties of all the bursts detected and localized by the IBIS instrument onboard the INTEGRAL satellite from November 2002 to September 2008. The sample is composed of 56 bursts, corresponding to a rate of ~ 0.8 GRB per month. Thanks to the performances of the INTEGRAL Burst Alert System, 50% of the IBIS GRBs have detected a

Michael E. Crenshaw

Minkowski spacetime is a convenient setting for the study of the relativistic dynamics of particles and fields in the vacuum. In order to study events that occur in a dielectric or other linear medium, we adopt the familiar continuum assumption of a linear, isotropic, homogeneous, transparent medium of refractive index n filling all space and seek the princi

Jonathan J. Heckman, Alireza Tavanfar, Cumrun Vafa

In this paper we study the interplay between the recently proposed F-theory GUTs and cosmology. Despite the fact that the parameter range for F-theory GUT models is very narrow, we find that F-theory GUTs beautifully satisfy most cosmological constraints without any further restrictions. The viability of the scenario hinges on the interplay between various c

Marcus Ansorg, Dorota Gondek-Rosińska, Loïc Villain

A highly accurate, multi-domain spectral code is used in order to construct sequences of general relativistic, differentially rotating neutron stars in axisymmetry and stationarity. For bodies with a spheroidal topology and a homogeneous or an N=1 polytropic equation of state, we investigate the solution space corresponding to broad ranges of degree of diffe

Nadav Drukker, Jan Plefka

We develop a compact representation of the one-loop n-point functions of all chiral primary operators in planar SU(N), N=4 super Yang-Mills theory in terms of tree-level disk correlation functions and the scalar one-loop box integral. As a check, known results for all four-point functions and for n-point extremal and near-extremal correlators are rederived.

Naihong Hu, Xiuling Wang

We construct convex PBW-type Lyndon bases for two-parameter quantum groups U_{r,s}({so}_{2n+1}) with detailed commutation relations. It turns out that under a certain condition, the restricted two-parameter quantum group u_{r,s}({so}_{2n+1}) (r, s are roots of unity) is of Drinfeld double. All of Hopf isomorphisms of u_{r,s}({so}_{2n+1}), as well as u_{r,s}(

Daniel Erman, Mauricio Velasco

We consider the question of which zero-dimensional schemes deform to a collection of distinct points; equivalently, we ask which Artinian k-algebras deform to a product of fields. We introduce a syzygetic invariant which sheds light on this question for zero-dimensional schemes of regularity two. This invariant imposes obstructions for smoothability in gener

Shlomo Dado, Arnon Dar

The two brightest and so far the best studied gamma ray bursts (GRBs), 990123 and 080319B, were ordinary, highly collimated GRBs produced in a core collapse supernova explosion within a high-density wind environment and observed from a very near-axis viewing angle. Inverse Compton scattering (ICS) and synchrotron radiation (SR), the two dominant radiation me

M. Unverzagt, P. Aguar-Bartolome, J. Ahrens, J. R. M. Annand

A precise measurement of the Dalitz plot parameter, alpha, for the eta->3pi^0 decay is presented. The experiment was performed with the Crystal Ball and TAPS large acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8*10^6 eta->3pi^0 events were obtained, giving the result alpha = -

Florin Diacu

We study singularities of the n-body problem in spaces of constant curvature and generalize certain results due to Painleve, Weierstrass, and Sundman. For positive curvature, some of our proofs use the correspondence between total collision solutions of the original system and their orthogonal projection--a property that offers a new method of approaching th

Shawn Andrews, Hans De Sterck, Stephen Inglis, Roger G. Melko

We study a classical fully-frustrated honeycomb lattice Ising model using Markov chain Monte Carlo methods and exact calculations . The Hamiltonian realizes a degenerate ground state manifold of equal-energy states, where each hexagonal plaquette of the lattice has one and only one frustrated bond, with an extensive residual entropy that grows as the number

Hsien-Hao Mei, Wei-Tou Ni, Sheng-Jui Chen, Sheau-shi Pan

Experiments for vacuum birefringence and vacuum dichroism have been set up with high-finesse high magnetic experimental apparatuses, which seem to be ideal for small gaseous Cotton-Mouton effect (CME) measurements. PVLAS Collaboration has measured CMEs in krypton, xenon and neon at the wavelength of 1064 nm. In this Letter, we report on our measurement of CM

Haisheng Li

This is a paper in a series to study vertex algebra-like structures arising from various algebras including quantum affine algebras and Yangians. In this paper, we study notions of $\hbar$-adic nonlocal vertex algebra and $\hbar$-adic (weak) quantum vertex algebra, slightly generalizing Etingof-Kazhdan&#39;s notion of quantum vertex operator algebra. For any

L. Borsten, D. Dahanayake, M. J. Duff, H. Ebrahim

We show that the three-qubit entanglement classes: (0) Null, (1) Separable A-B-C, (2a) Biseparable A-BC, (2b) Biseparable B-CA, (2c) Biseparable C-AB, (3) W and (4) GHZ correspond respectively to ranks 0, 1, 2a, 2b, 2c, 3 and 4 of a Freudenthal triple system defined over the Jordan algebra C+C+C. We also compute the corresponding SLOCC orbits.

A. F. Croxall, K. Das Gupta, C. A. Nicoll, H. E. Beere

We report single layer resistivities of 2-dimensional electron and hole gases in an electron-hole bilayer with a 10nm barrier. In a regime where the interlayer interaction is stronger than the intralayer interaction, we find that an insulating state ($dρ/dT < 0$) emerges at $T\sim1.5{\rm K}$ or lower, when both the layers are simultaneously present. This hap

John Gibbons, Paolo Lorenzoni, Andrea Raimondo

We study purely nonlocal Hamiltonian structures for systems of hydrodynamic type. In the case of a semi-Hamiltonian system, we show that such structures are related to quadratic expansions of the diagonal metrics naturally associated with the system.

R. A. Blythe

We introduce a class of stochastic models for the dynamics of two linguistic variants that are competing to become the single, shared convention within an unstructured community of speakers. Different instances of the model are distinguished by the way agents handle variability in the language (i.e., multiple forms for the same meaning). The class of models

P. P. Avelino, D. Bazeia, R. Menezes, J. Oliveira

This work deals with bifurcation and pattern changing in models described by two real scalar fields. We consider generic models with quartic potentials and show that the number of independent polynomial coefficients affecting the ratios between the various domain wall tensions can be reduced to 4 if the model has a superpotential. We then study specific one-

Joan Josep Ferrando, Juan Antonio Sáez

We give the necessary and sufficient (local) conditions for a metric tensor to be the Kerr solution. These conditions exclusively involve explicit concomitants of the Riemann tensor.

G. I. Lykasov, Z. M. Karpova, M. N. Sergeenko, V. A. Bednyakov

Transverse momentum spectra of charmed and beauty mesons produced in proton-proton and proton-antiproton collisions at high energies are analyzed within the modified quark-gluon string model (QGSM) including the internal motion of quarks in colliding hadrons. It is shown that this approach can describe rather satisfactorily the experimental data at not large

Murugeswaran Duraisamy, Alexander L. Kagan

CLEO-c measurements of the timelike form factors F_pi, F_K at \sqrt{s}=3.671 GeV provide a direct probe of power corrections (PC&#39;s) at energies near m_B. PC&#39;s in F_pi, F_K and B \to K pi, pi pi are separated into perturbative and soft parts. In F_pi, F_K the latter are \ge O(10) larger. A PC fit to the B \to K pi, pi pi data also yields a \ge O(10) s

Pei-Lin You

Using special capacitors our experiments discovered that the ground state K, Rb or Cs atom is polar atom with a large permanent electric dipole moment (EDM) of the order of eao (ao is Bohr radius) as excited state of hydrogen atom. But we can not calculate the EDM of an atom using Boltzmann constant. The mechanism of polar atoms by which orientation polariza

Stefania Salvadori, Andrea Ferrara

We investigate the nature of the newly discovered Ultra Faint dwarf spheroidal galaxies (UF dSphs) in a general cosmological context simultaneously accounting for various ``classical`` dSphs and Milky Way properties including their Metallicity Distribution Function (MDF). To this aim we extend the merger tree approach previously developed to include the pres

Julien Toulouse, Iann C. Gerber, Georg Jansen, Andreas Savin

An adiabatic-connection fluctuation-dissipation theorem approach based on a range separation of electron-electron interactions is proposed. It involves a rigorous combination of short-range density functional and long-range random phase approximations. This method corrects several shortcomings of the standard random phase approximation and it is particularly

S. Jadach, W. Placzek, M. Skrzypek, P. Stoklosa

We present the program EvolFMC v.2 that solves the evolution equations in QCD for the parton momentum distributions by means of the Monte Carlo technique based on the Markovian process. The program solves the DGLAP-type evolution as well as modified-DGLAP ones. In both cases the evolution can be performed in the LO or NLO approximation. The quarks are treate

Y. Brihaye, E. Radu

We propose to compute the action and global charges of the asymptotically de Sitter solutions in Einstein-Gauss-Bonnet theory by using the counterterms method in conjunction with the quasilocal formalism. The general expression of the counterterms and the boundary stress tensor is presented for spacetimes of dimension $d\leq 7$. We apply this tehnique for se

S. Prolhac, M. R. Evans, K. Mallick

We find the exact solution for the stationary state measure of the partially asymmetric exclusion process on a ring with multiple species of particles. The solution is in the form of a matrix product representation where the matrices for a system of N species are defined recursively in terms of the matrices for a system of N-1 species. A complete proof is gi

C. Semay, F. Buisseret, B. Silvestre-Brac

A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schrödinger equation with such a potential is presented. When appli

J Ben Geloun, F G Scholtz

Supersymmetric quantum mechanics is formulated on a two dimensional noncommutative plane and applied to the supersymmetric harmonic oscillator. We find that the ordinary commutative supersymmetry is partially broken and only half of the number of supercharges are conserved. It is argued that this breaking is closely related to the breaking of time reversal s

Timm Krüger, Fathollah Varnik, Dierk Raabe

A thorough study of shear stress within the lattice Boltzmann method is provided. Via standard multiscale Chapman-Enskog expansion we investigate the dependence of the error in shear stress on grid resolution showing that the shear stress obtained by the lattice Boltzmann method is second order accurate. This convergence, however, is usually spoiled by the b

R. Baldini, S. Pacetti, A. Zallo

A peculiar feature, observed in the BaBar data on e+e- -> baryon-antibaryon cross sections, is the non-vanishing cross section at threshold for all these processes. This is the expectation due to the Coulomb enhancement factor acting on a charged fermion pair. Remarkably, in the case of e+e- -> p-pbar it is found that Coulomb final state interactions largely

Celine Boehm, Julien Lavalle

We derive the covariant formalism associated with the relativistic Sunyaev-Zel&#39;dovich effect due to a non-thermal population of high energy electrons in clusters of galaxies. More precisely, we show that the formalism proposed by Wright in 1979, based on an empirical approach (and widely used in the literature) to compute the inverse Compton scattering o