October 2007 arXiv papers

Alexandru D. Ionescu, Sergiu Klainerman

We prove two uniqueness theorems for solutions of linear and nonlinear wave equations; the first theorem is in the Minkowski space while the second is in the domain of outer communication of a Kerr black hole. Both theorems concern ill posed Cauchy problems on smooth, bifurcate, characteristic hypersurfaces. In the case of the Kerr space-time this hypersurfa

Alexander Komech, Andrew Komech

We review recent results on global attractors of U(1)-invariant dispersive Hamiltonian systems. We study several models based on the Klein-Gordon equation and sketch the proof that in these models, under certain generic assumptions, the weak global attractor is represented by the set of all solitary waves. In general, the attractors may also contain multifre

V. M. Lipunov, V. G. Kornilov, A. V. Krylov, N. V. Tyurina

We present the results of observations obtained using the MASTER robotic telescope in 2005 - 2006, including the earliest observations of the optical emission of the gamma-ray bursts GRB 050824 and GRB 060926. Together with later observations, these data yield the brightness-variation law t^{-0.55+-0.05} for GRB 050824. An optical flare was detected in GRB 0

Dumitru Astefanesei, Horatiu Nastase, Hossein Yavartanoo, Sangheon Yun

We investigate the attractor mechanism in gauged supergravity in the presence of higher derivatives terms. In particular, we discuss the attractor behaviour of static black hole horizons in anti-de Sitter spacetime by using the effective potential approach as well as Sen's entropy function formalism. We use the holographic techniques to interpret the mod

Heath Emerson, Ralf Meyer

We study several duality isomorphisms between equivariant bivariant K-theory groups, generalising Kasparov's first and second Poincare duality isomorphisms. We use the first duality to define an equivariant generalisation of Lefschetz invariants of generalised self-maps. The second duality is related to the description of bivariant Kasparov theory for co

Heath Emerson, Ralf Meyer

Let X be a locally compact space with a continuous proper action of a locally compact group G. Assuming that X satisfies a certain kind of duality in equivariant bivariant Kasparov theory, we can enrich the classical construction of Lefschetz numbers to equivariant K-homology classes. We compute the Lefschetz invariants for self-maps of finite-dimensional si

R. Gonzalez Felipe, N. M. C. Santos

In light of the five-year data from the Wilkinson Microwave Anisotropy Probe (WMAP), we discuss models of inflation based on the pseudo Nambu-Goldstone potential predicted in five-dimensional gauge theories for different backgrounds: flat Minkowski, anti-de Sitter, and dilatonic spacetime. In this framework, the inflaton potential is naturally flat due to sh

R. F. Sobreiro, V. J. Vasquez Otoya

In this work, we show that a class of metric-affine gravities can be reduced to a Riemann-Cartan one. The reduction is based on the cancelation of the nonmetricity against the symmetric components of the spin connection. A heuristic proof, in the Einstein-Cartan formalism, is performed in the special case of diagonal unitary tangent metric tensor. The result

Adriana Pálffy, Jörg Evers, Christoph H. Keitel

Electric dipole-forbidden transitions of nuclei interacting with super-intense laser fields are investigated considering stable isotopes with suitable low-lying first excited states. Different classes of transitions are identified, and all magnetic sublevels corresponding to the near-resonantly driven nuclear transition are included in the description of the

Nathan Broaddus

By the work of Harer, the reduced homology of the complex of curves is a fundamental cohomological object associated to all torsion free finite index subgroups of the mapping class group. We call this homology group the Steinberg module of the mapping class group. It was previously known that the curve complex has the homotopy type of a bouquet of spheres. H

Tanmay Vachaspati

The functional Schrodinger equation is used to study the quantum collapse of a gravitating, spherical domain wall and a massless scalar field coupled to the metric. The approach includes backreaction of pre-Hawking radiation on the gravitational collapse. Truncating the degrees of freedom to a minisuperspace leads to an integro-differential Schrodinger equat

Edward Shuryak

We propose a scenario for bottom-up gravity dual picture of QCD-like theories, which consists of two near-AdS$_5$ domains separated by the ``domain wall'' at which the effective coupling relatively rapidly switches from small perturbative value at its UV side to strong at its IR side. Its consequence are corresponding jumps in 5-d masses of the bulk

Shaffique Adam, S. Das Sarma

A Drude-Boltzmann theory is used to calculate the transport properties of bilayer graphene. We find that for typical carrier densities accessible in graphene experiments, the dominant scattering mechanism is overscreened Coulomb impurities that behave like short-range scatterers. We anticipate that the conductivity $σ(n)$ is linear in $n$ at high density and

Debbie Leung, Joungkeun Lim, Peter Shor

We present a communication protocol for the erasure channel assisted by backward classical communication, which achieves a significantly better rate than the best prior result. In addition, we prove an upper bound for the capacity of the channel. The upper bound is smaller than the capacity of the erasure channel when it is assisted by two-way classical comm

Stewart Priddy

This paper is a survey of the stable homotopy theory of BG for G a finite group. It is based on a series of lectures given at the Summer School associated with the Topology Conference at the Vietnam National University, Hanoi, August 2004.

Edward Frenkel, Edward Witten

The geometric Langlands correspondence has been interpreted as the mirror symmetry of the Hitchin fibrations for two dual reductive groups. This mirror symmetry, in turn, reduces to T-duality on the generic Hitchin fibers, which are smooth tori. In this paper we study what happens when the Hitchin fibers on the B-model side develop orbifold singularities. Th

J. L. Hora, M. Cohen, R. G. Ellis, M. Meixner

We present IRAC and MIPS images and photometry of a sample of previously known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in the survey field, 185 objects were detected in at least two of the IRAC bands, and 161 detected in the MIPS 24 micron images. Color-

K. Dusling, D. Teaney

In this work we simulate a viscous hydrodynamical model of non-central Au-Au collisions in 2+1 dimensions, assuming longitudinal boost invariance. The model fluid equations were proposed by Öttinger and Grmela \cite{OG}. Freezeout is signaled when the viscous corrections become large relative to the ideal terms. Then viscous corrections to the transverse mom

Teodor Banica, Serban Belinschi, Mireille Capitaine, Benoit Collins

We introduce and study a remarkable family of real probability measures $π_{st}$, that we call free Bessel laws. These are related to the free Poisson law $π$ via the formulae $π_{s1}=π^{\boxtimes s}$ and $π_{1t}=π^{\boxplus t}$. Our study includes: definition and basic properties, analytic aspects (supports, atoms, densities), combinatorial aspects (functio

L. A. M. Souza, M. C. Nemes, M. França Santos, J. G. Peixoto de Faria

The dissipative dynamics of Gaussian squeezed states (GSS) and coherent superposition states (CSS) are analytically obtained and compared. Time scales for sustaining different quantum properties such as squeezing, negativity of the Wigner function or photon number distribution are calculated. Some of these characteristic times also depend on initial conditio

D. Kreinick

Recent results in studies of bottomonium especially relevant to charmonium are reviewed. This report covers dipion transition matrix elements, $η$ production in $Υ$ transitions, $Υ$ decays to invisible particles, a search for a non-standard-model pseudoscalar Higgs in $Υ$ radiative decays, and $Υ$ radiative decays to $\rm{f_2(1270)}$, $η$, and $η'$.

Paul H. Frampton, Shinya Matsuzaki

Spontaneously broken flavor symmetry involving the binary tetrahedral group $T^{'}$ relates parameters in the standard model. In one example the CP violating Pontecorvo-Maki-Nakagawa-Sakata phase $δ_{PMNS}$ and atmospheric mixing angle $θ_{23}$ of neutrinos are related to the Cabibbo mixing angle $Θ_C$ for quarks. A second formula relates a ratio of neut

Shizuo Kaji

We determine the mod $2$ cohomology over the Steenrod algebra of the classifying spaces of the free loop groups $LG$ for compact groups $G=Spin(7)$, $Spin(8)$, $Spin(9)$, and $F_4$. Then, we show that they are isomorphic as algebras over the Steenrod algebra to the mod $2$ cohomology of the corresponding Chevalley groups of type $G(q)$, where $q$ is an odd p

Earnest Akofor, A. P. Balachandran, Sang G. Jo, Anosh Joseph

Modern cosmology has now emerged as a testing ground for theories beyond the standard model of particle physics. In this paper, we consider quantum fluctuations of the inflaton scalar field on certain noncommutative spacetimes and look for noncommutative corrections in the cosmic microwave background (CMB) radiation. Inhomogeneities in the distribution of la

M. Sereno, F. De Luca

The primary optical caustic surface behind a Kerr black hole is a four-cusped tube displaced from the line of sight. We derive the caustic surface in the nearly asymptotic region far from the black hole through a Taylor expansion of the lightlike geodesics up to and including fourth-order terms in m/b and a/b, where $m$ is the black hole mass, a the spin and

Pijushpani Bhattacharjee, Sovan Chakraborty, Srirupa Das Gupta, Kamales Kar

We derive upper limits on the ratio $f_{GRB/CCSN}(z) \equiv R_{GRB}(z)/R_{CCSN}(z) \equiv f_{GRB/CCSN}(0)(1+z)^α$, the ratio of the rate, $R_{GRB}$, of long-duration Gamma Ray Bursts (GRBs) to the rate, $R_{CCSN}$, of core-collapse supernovae (CCSNe) in the Universe ($z$ being the cosmological redshift and $α\geq 0$), by using the upper limit on the diffuse

Dirk Segers, Lise Van Proeyen, Willem Veys

Let f be a regular function on a nonsingular complex algebraic variety of dimension d. We prove a formula for the motivic zeta function of f in terms of an embedded resolution. This formula is over the Grothendieck ring itself, and specializes to the formula of Denef and Loeser over a certain localization. We also show that the space of n-jets satisfying f=0

Laurent Bruneau, Alain Joye, Marco Merkli

We consider a quantum system S interacting sequentially with independent systems E_m, m=1,2,... Before interacting, each E_m is in a possibly random state, and each interaction is characterized by an interaction time and an interaction operator, both possibly random. We prove that any initial state converges to an asymptotic state almost surely in the ergodi

Pradip Mukherjee, Anirban Saha

The leading order corrections to Reissner--Nordstrom solutions of the Einstein's equations on noncommutative space time have been worked out basing on a noncommutative gauge theory of gravity. From the corrcted metric the horizons have been derived and the curvature scalar is also computed. The introduction of noncommutativity leads to the removal of the

R. de Gail, N. Regnault, M. O. Goerbig

We consider trial wavefunctions exhibiting SU(K) symmetry which may be well-suited to grasp the physics of the fractional quantum Hall effect with internal degrees of freedom. Systems of relevance may be either spin-unpolarized states (K=2), semiconductors bilayers (K=2,4) or graphene (K=4). We find that some introduced states are unstable, undergoing phase

N. Crampe, L. Frappat, E. Ragoucy

We consider the thermodynamical limit of a gl(N) spin chain with arbitrary representation at each site of the chain. We consider excitations (with holes and new strings) above the vacuum and compute their corrections in 1/L to the densities and the energy.

Pavel Exner

The aim of this review is to provide an overview of a recent work concerning ``leaky'' quantum graphs described by Hamiltonians given formally by the expression $-Δ-αδ(x-Γ)$ with a singular attractive interaction supported by a graph-like set in $\mathbb{R}^ν,\: ν=2,3$. We will explain how such singular Schrödinger operators can be properly defined f

Tom Coates, Yongbin Ruan

We give an expository account of a conjecture, developed by Coates--Corti--Iritani--Tseng and Ruan, which relates the quantum cohomology of a Gorenstein orbifold X to the quantum cohomology of a crepant resolution Y of X. We explore some consequences of this conjecture, showing that it implies versions of both the Cohomological Crepant Resolution Conjecture

Antonio Galves, Florencia Leonardi

In this paper we obtain non-uniform exponential upper bounds for the rate of convergence of a version of the algorithm Context, when the underlying tree is not necessarily bounded. The algorithm Context is a well-known tool to estimate the context tree of a Variable Length Markov Chain. As a consequence of the exponential bounds we obtain a strong consistenc

Valentin Féray

Kerov's polynomials give irreducible character values in term of the free cumulants of the associated Young diagram. We prove in this article a positivity result on their coefficients, which extends a conjecture of S. Kerov. Our method, through decomposition of maps, gives a description of the coefficients of the k-th Kerov's polynomials using permut

Yen-Jen Oyang, Chien-Yu Chen, Darby Tien-Hao Chang, Chih-Peng Wu

This article proposes a novel density estimation based algorithm for carrying out supervised machine learning. The proposed algorithm features O(n) time complexity for generating a classifier, where n is the number of sampling instances in the training dataset. This feature is highly desirable in contemporary applications that involve large and still growing

Alexandre Eremenko

For real power series whose non-zero coefficients satisfy $|a_m|^{1/m}\to~1$ we prove a stronger version of Fabry theorem relating the frequency of sign changes in the coefficients and analytic continuation of the sum of the power series.

Robert B. Gramacy, Joo Hee Lee, Ricardo Silva

Quantitative portfolio allocation requires the accurate and tractable estimation of covariances between a large number of assets, whose histories can greatly vary in length. Such data are said to follow a monotone missingness pattern, under which the likelihood has a convenient factorization. Upon further assuming that asset returns are multivariate normally

Ta Khongsap, Weiqiang Wang

The notion of rational spin double affine Hecke algebras (sDaHa) and rational double affine Hecke-Clifford algebras (DaHCa) associated to classical Weyl groups are introduced. The basic properties of these algebras such as the PBW basis and Dunkl operator representations are established. An algebra isomorphism relating the rational DaHCa to the rational sDaH

Takehiro Azuma, Pallab Basu, Spenta R. Wadia

In the study of the small ten-dimensional Schwarzschild blackhole, the blackhole to string transition is an important problem. In hep-th/0605041, a possible identification is made between the Gross-Witten-Wadia (GWW) type third-order large-N phase transition in the boundary gauge theory and the string-black hole transition in the bulk. In this paper, we exhi

Meng-Chwan Tan

We study the two-dimensional twisted (0,2) sigma-model on various smooth complex flag manifolds G/B, and explore its relevance to the geometric Langlands program. We find that an equivalence - at the level of the holomorphic chiral algebra - between a bosonic string on G/B and a B-gauged version of itself on G, will imply an isomorphism of classical W-algebr

Werner Bley, Henri Johnston

Let E be a number field and G be a finite group. Let A be any O_E-order of full rank in the group algebra E[G] and X be a (left) A-lattice. We give a necessary and sufficient condition for X to be free of given rank d over A. In the case that the Wedderburn decomposition of E[G] is explicitly computable and each component is in fact a matrix ring over a fiel

Andrzej A. Skorupski

Four generalizations of the Phase Integral Approximation (PIA) to sets of N ordinary differential equations of the Schroedinger type: u_j''(x) + Sum{k = 1 to N} R_{jk}(x) u_k(x) = 0, j = 1 to N, are described. The recurrence relations for higher order corrections are given in the form valid in arbitrary order and for the matrix R_{jk} either hermitia

D. D. Han, J. G. Liu, Y. G. Ma

The scaling behavior of fluctuation for a download network which we have investigated a few years ago based upon Zhang&#39;s Encophysics web page has been presented. A power law scaling, namely $σ\sim < f> ^ α$ exists between the dispersion $σ$ and average flux $<f>$ of the download rates. The fluctuation exponent $α$ is neither 1/2 nor 1 which was claimed a

Tony J. Puthenpurakal

We give an elementary proof of Grothendieck&#39;s non-vanishing Theorem: For a finitely generated non-zero module $M$ over a Noetherian local ring $A$ with maximal ideal $\m$, the local cohomology module $H^{\dim M}_{\m}(M)$ is non-zero.

L. R. Ribeiro, E. Passos, C. Furtado, J. R. Nascimento

We analyze the nonrelativistic quantum dynamics of a single neutral spin half particle, with non-zero magnetic and electric dipole moments, moving in an external electromagnetic field in presence of Lorentz symmetry violation background. Also, we study the geometric phase for this model taking into account the parameter that breaks the Lorentz symmetry. We i

Wilfried Buchmüller

The classical picture of GUT baryogenesis has been strongly modified by theoretical progress concerning two nonperturbative features of the standard model: the phase diagram of the electroweak theory, and baryon and lepton number changing sphaleron processes in the high-temperature symmetric phase of the standard model. We briefly review three viable models,

E. Mukhin, V. Tarasov, A. Varchenko

We prove that if all roots of the discrete Wronskian with step 1 of a set of quasi-exponentials with real bases are real, simple and differ by at least 1, then the complex span of this set of quasi-exponentials has a basis consisting of quasi-exponentials with real coefficients. This result generalizes the B. and M.Shapiro conjecture about spaces of polynomi

Peter M. Akhmet&#39;ev

It is proved that there exists an integer $L$ such that a framed manifold of dimension $2^l-2$, $l\le L$ has the trivial Kervaire Invariant.

Masakiyo Kitazawa, Teiji Kunihiro, Kazuya Mitsutani, Yukio Nemoto

We study the properties of massless and massive quarks coupled with a scalar and pseudoscalar boson at finite temperature in Yukawa models at the one-loop order. The behavior of the spectral function and the pole structure of the propagator are analyzed as functions of temperature $T$ and the quark mass $m_f$. It is shown that the three-peak structure of the

V. Lisy, J. Tothova, B. Brutovsky

The screening of hydrodynamic interactions (HI) essentially affects macroscopic properties of polymeric solutions. This screening depends not only on the polymer concentration but has a dynamic nature. In the present work, a bead-spring theory is developed, in which this phenomenon is described for solutions of nonentangled polymer coils. The equation of mot

J. A. Combi, J. F. Albacete-Colombo, J. Marti

Microquasars are ideal natural laboratories for understanding accretion/ejection processes, studying the physics of relativistic jets, and testing gravitational phenomena. Nevertheless, these objects are difficult to find in our Galaxy. The main goal of this work is to increase the number of known systems of this kind. We have developed an improved search st

T. O. Wehling, A. V. Balatsky, A. M. Tsvelik, M. I. Katsnelson

We investigate the electronic properties of corrugated graphene and show how rippling-induced pseudomagnetic fields alter graphene&#39;s low-energy electronic properties by combining first principles calculations with an effective field theory. The formation of flat bands near the Fermi level corresponding to pseudo-Landau levels is studied as a function of

Fernando G. S. L. Brandao, Martin. B. Plenio

We consider the manipulation of multipartite entangled states in the limit of many copies under quantum operations that asymptotically cannot generate entanglement. As announced in [Brandao and Plenio, Nature Physics 4, 8 (2008)], and in stark contrast to the manipulation of entanglement under local operations and classical communication, the entanglement sh

O. Cakir, K. O. Ozansoy

We investigate the effects of unparticles on Compton scattering, e gamma -> e gamma based on a future e^+e^- linear collider such as the CLIC. For different polarization configurations, we calculate the lower limits of the unparticle energy scale Lambda_U for a discovery reach at the center of mass energies sqrt(s)=0.5 TeV- 3 TeV. It is shown that, especiall

T. Nishimura, A. Matsumoto, H. Yabu

Atom-molecule equilibrium for molecular formation processes is discussed for boson-fermion, fermion-fermion, and boson-boson mixtures of ultracold atomic gases in the framework of quasichemical equilibrium theory. After presentation of the general formulation, zero-temperature phase diagrams of the atom-molecule equilibrium states are calculated analytically

Maarten Solleveld

Let G be a reductive p-adic group, H(G) its Hecke algebra and S(G) its Schwartz algebra. We will show that these algebras have the same periodic cyclic homology. This might be used to provide an alternative proof of the Baum-Connes conjecture for G, modulo torsion. As preparation for our main theorem we prove two results that have independent interest. First

Mahito Kohmoto, Daijiro Tobe

We study one dimensional quasiperiodic system obtained from the tight-binding model on the square lattice in a uniform magnetic field with the spin orbit interaction. The phase diagram with respect to the Harper coupling and the Rashba coupling are proposed from a number of numerical studies including a multifractal analysis. There are four phases, I, II, II

Omar Mustafa, S. Habib Mazharimousavi

A family of spherical non-Hermitian potentials is studied. It is shown that the corresponding non-Hermitian Hamiltonians admit some &#34;new&#34; P$phi$T$phi$-symmetry. It is observed that whilst such P$phi$T$phi$-symmetric Hamiltonians just copy the eigenvalues of V(r), the corresponding wavefunctions would rather indulge some new probabilistic interpretati

S. Salimi

In the present paper, we study the continuous-time quantum walk on quotient graphs. On such graphs, there is a straightforward reduction of problem to a subspace that can be considerably smaller than the original one. Along the lines of reductions, by using the idea of calculation of the probability amplitudes for continuous-time quantum walk in terms of the

A. G. Sykes, D. M. Gangardt, M. J. Davis, K. Viering

We analytically calculate the spatial nonlocal pair correlation function for an interacting uniform 1D Bose gas at finite temperature and propose an experimental method to measure nonlocal correlations. Our results span six different physical realms, including the weakly and strongly interacting regimes. We show explicitly that the characteristic correlation

Takahiro Hatano, Tetsuya Kaneko, Yousuke Abe, Hideki Matsui

Pinning interaction between a screw dislocation and a void in fcc copper is investigated by means of molecular dynamics simulation. A screw dislocation bows out to undergo depinning on the original glide plane at low temperatures, where the behavior of the depinning stress is consistent with that obtained by a continuum model. If the temperature is higher th

Xin-Bing Huang

The theory of gravitation in the spacetime with Finsler structure is constructed. It is shown that the theory keeps general covariance. Such theory reduces to Einstein&#39;s general relativity when the Finsler structure is Riemannian. Therefore, this covariant theory of gravitation is an elegant realization of Einstein&#39;s thoughts on gravitation in the sp

Scott D. Kominers, Zachary Abel

We show that if L is an extremal even unimodular lattice of rank 40r with r=1,2,3 then L is generated by its vectors of norms 4r and 4r+2. Our result is an extension of Ozeki&#39;s result for the case r=1.

Yuval Nardi, David O. Siegmund, Benjamin Yakir

Motivated by the problem of testing for the existence of a signal of known parametric structure and unknown ``location&#39;&#39; (as explained below) against a noisy background, we obtain for the maximum of a centered, smooth random field an approximation for the tail of the distribution. For the motivating class of problems this gives approximately the sign

Tetsufumi Hirano, Ulrich W. Heinz, Dmitri Kharzeev, Roy Lacey

We simulate the dynamics of Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) with a hybrid model that treats the dense early quark-gluon plasma (QGP) stage macroscopically as an ideal fluid, but models the dilute late hadron resonance gas (HG) microscopically using a hadronic cascade. By comparing with a pure hydrodynamic approach we identify e

Ying-Qiu Gu

If there is a null gradient field in 1+3 dimensional space-time, we can set up a kind of light-cone coordinate system in the space-time. In such coordinate system, the metric takes a simple form, which is much helpful for simplifying and solving the Einstein&#39;s field equation. This light-cone coordinate system has wonderful properties and has been widely

Richard Cleve, Dmytro Gavinsky, David L. Yonge-Mallo

We present a bounded-error quantum algorithm for evaluating Min-Max trees. For a tree of size N our algorithm makes N^{1/2+o(1)} comparison queries, which is close to the optimal complexity for this problem.

F. G. Garvan

Let spt(n) denote the total number of appearances of smallest parts in the partitions of n. Recently, Andrews showed how spt(n) is related to the second rank moment, and proved some surprising Ramanujan-type congruences mod 5, 7 and 13. We prove a generalization of these congruences using known relations between rank and crank moments. We obtain explicit Ram

Theodore Yaotsu Wu

This study is on Cauchy&#39;s function $f(z)$ and its integral, $J[f(z)]\equiv (2πi)^{-1}\oint_C f(t)dt/(t-z)$ taken along a closed simple contour $C$, in regard to their comprehensive properties over the entire $z=x+iy$ plane consisted of the open domain ${\cal D}^+$ bounded by $C$ and the open domain ${\cal D}^-$ outside $C$. (i) With $f(z)$ assumed to be

Luc Dessart, Adam Burrows, Eli Livne, Christian Ott

Recent stellar evolutionary calculations of low-metallicity massive fast-rotating main-sequence stars yield iron cores at collapse endowed with high angular momentum. It is thought that high angular momentum and black hole formation are critical ingredients of the collapsar model of long-soft gamma-ray bursts (GRBs). Here, we present 2D multi-group, flux-lim

Petr M. Akhmet&#39;ev

We develop a geometric approach to stable homotopy groups of spheres in the spirit of the work of Pontrjagin and Rokhlin. A new proof of the Hopf Invariant One Theorem by J.F.Adams is obtained in all dimensions except 15 and 31. To prove that the stable Hopf invariant H: Π_n \to Z/2 vanishes for n>31, we apply methods of geometric topology. The Pontrjagin-Th

N. Raj Rao, Alan Edelman

We define a class of &#34;algebraic&#34; random matrices. These are random matrices for which the Stieltjes transform of the limiting eigenvalue distribution function is algebraic, i.e., it satisfies a (bivariate) polynomial equation. The Wigner and Wishart matrices whose limiting eigenvalue distributions are given by the semi-circle law and the Marcenko-Pas

B. E. Zhilyaev, M. V. Andreev, A. V. Sergeev, V. B. Petkov

22 Sep 2005 Swift-BAT triggered and located GRB050922C. The light curve shows the intense broad peak with $T_{90}$ of $(5 \pm 1)$ s. The Nordic Optical Telescope has obtained spectra of the afterglow with several absorption features corresponding to a redshift of $z = 2.17 \pm 0.03$. Observation of optical transient of GRB050922C was carried out in the R-ban

Roderich Tumulka

The Ghirardi-Rimini-Weber (GRW) theory is a physical theory that, when combined with a suitable ontology, provides an explanation of quantum mechanics. The so-called collapse of the wave function is problematic in conventional quantum theory but not in the GRW theory, in which it is governed by a stochastic law. A possible ontology is the flash ontology, acc

Pierre Teyssandier, Christophe Le Poncin-Lafitte, Bernard Linet

In almost all of the studies devoted to the time delay and the frequency shift of light, the calculations are based on the integration of the null geodesic equations. However, the above-mentioned effects can be calculated without integrating the geodesic equations if one is able to determine the bifunction $Ω(x_A, x_B)$ giving half the squared geodesic dista

A. J. Onifer, A. Heger, J. Abdallah

We produce models of early WN, WC, and WO stars as a function of metallicity Z using an analytic CAK-type approach. At log(Z / Z_sun) >= -2 both WN and WC stars have the approximate dependence Mdot \propto Z^{0.5}. For a WN wind the mass-loss rate drops rapidly below log(Z / Z_sun) = -2, and no wind solution can be found for log(Z / Z_sun) < -3. For WC and W

Vadim S. Kaplunovsky

I put metastable supersymmetry breaking in a cosmological context. I argue that under reasonable assumptions, the cooling down early Universe favors metastable SUSY-breaking vacua over the stable supersymmetric vacua. To illustrate the general argument, I analyze the early-Universe history of the Intriligator-Seiberg-Shih model.

Kaushik Mitra, C. J. Williams, C. A. R. Sa de Melo

Weakly interacting atomic or molecular bosons in quantum degenerate regime and trapped in harmonically confined optical lattices, exhibit a wedding cake structure consisting of insulating (Mott) shells. It is shown that superfluid regions emerge between Mott shells as a result of fluctuations due to finite hopping. It is found that the order parameter equati

Antonio Pich

The B Factories have generated a large amount of new results on the tau lepton. The present status of some selected topics on tau physics is presented: charged-current universality tests, bounds on lepton-flavour violation, the determination of alpha_s from the inclusive tau hadronic width, and the measurement of |V_{us}| through the Cabibbo-suppressed decay

Octavio Cardona, Lucio Crivellari, Eduardo Simonneau

A mayor problem that arises in the computation of stellar atmosphere models is the self consistent determination of the temperature distribution via the constraint of energy conservation. The energy balance includes the gains due to the absorption of radiation and the losses due to emission. It is well known that within each one of the two above integrals th

Yasumichi Aoki, Zoltan Fodor, Sandor D. Katz, Kalman K. Szabo

A quantitative comparison between the finite temperature behaviour of the staggered and Wilson fermion formulations are performed. The comparison is based on a physical quantity that is expected to be quite sensitive to the fermionic features of the action. For that purpose we use the height of the peak for $dχ_s/dT$, where $χ_s$ is the quark number suscepti

Ph. de Forcrand, M. A. Stephanov, U. Wenger

Using a canonical formalism, we determine the equation of state and the phase diagram of eight-flavour QCD, as a function of temperature and isospin density. Two mechanisms are at work: Bose condensation of pions at high density, and deconfinement at high temperature. We study their interplay and find that on our small and coarse lattice the first order deco

C. Bernard, C. Davies, C. DeTar, Steven Gottlieb

The MILC collaboration&#39;s simulations with improved staggered quarks are being extended with runs at a lattice spacing of 0.06 fm with quark masses down to one tenth the strange quark mass. We give a brief introduction to these new simulations and the determination of the lattice spacing. Then we combine these new runs with older results to study the mass

Lisa M. Winter, Richard F. Mushotzky, Jack Tueller, Craig Markwardt

The SWIFT gamma ray observatory&#39;s Burst Alert Telescope (BAT) has detected a sample of active galactic nuclei (AGN) based solely on their hard X-ray flux (14-195 keV). In this paper, we present for the first time {\it XMM-Newton} X-ray spectra for 22 BAT AGNs with no previously analyzed X-ray spectra. If our sources are a representative sample of the BAT

G. A. Guerrero, E. M. de G. Dal Pino

Flux-dominated solar dynamo models have demonstrated to reproduce the main features of the large scale solar magnetic cycle, however the use of a solar like differential rotation profile implies in the the formation of strong toroidal magnetic fields at high latitudes where they are not observed. In this work, we invoke the hypothesis of a thin-width tachocl

Magda Peligrad, Sunder Sethuraman

A well-known result with respect to the one dimensional nearest-neighbor symmetric simple exclusion process is the convergence to fractional Brownian motion with Hurst parameter 1/4, in the sense of finite-dimensional distributions, of the subdiffusively rescaled current across the origin, and the subdiffusively rescaled tagged particle position. The purpose

Jogia Bandyopadhyay

We derive a lower bound for the Wehrl entropy in the setting of SU(1,1). For asymptotically high values of the quantum number k, this bound coincides with the analogue of the Lieb-Wehrl conjecture for SU(1,1) coherent states. The bound on the entropy is proved via a sharp norm bound. The norm bound is deduced by using an interesting identity for Fisher infor

Alexis Larranaga

In this paper we will show that using the cosmological constant as a new thermodynamical state variable, the differential and integral mass formulas of the first law of thermodynamics for asymptotic flat spacetimes can be extended to be used at the two horizons of the (2+1) dimensional BTZ black hole. We also extend this equations to the stringy description

Tony Y. Abi-Salloum

In this paper we explore the physical origin of the transparency induced in absorbing three-level cascade atoms by the simultaneous interplay of two coherent beams of light. By utilizing the scattering technique we offer what we believe is a very convincing physical evidence for the existence, or for the absence, of quantum interference effects in the Autler

Mariusz Puchalski, Andrzej Czarnecki, Savely G. Karshenboim

We present a precise theoretical prediction for the decay width of the bound state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-) = 2.087 085(12)/ns. We include O(alpha^2) effects of hard virtual photons as well as soft corrections to the wave function and the decay amplitude. An outcome of a large-scale variational calculation, th

Markus J. Aschwanden

Our understanding of fundamental processes in the solar corona has been greatly progressed based on the space observations of SMM, Yohkoh, Compton GRO, SOHO, TRACE, RHESSI, and STEREO. We observe now acoustic waves, MHD oscillations, turbulence-related line broadening, magnetic configurations related to reconnection processes, and radiation from high-energy

Stacy H. Teng, S. Veilleux, A. S. Wilson, A. J. Young

We report on the detection of Fe Kalpha emission in F04103$-$2838, an ultraluminous infrared galaxy (ULIRG; log[L$_{\rm IR}$/L$_\odot$] $\ge$ 12) that is optically classified as a LINER. Previous {\it Chandra} observations suggested the presence of both a starburst and an AGN in this source. A deeper ($\sim$20 ksec) {\it XMM-Newton} spectrum reveals an Fe Ka

Leslie Ballentine

The concept of probability was prominent in the original foundations of quantum mechanics, and continues to be so today. Indeed, the controversies regarding objective and subjective interpretations of probability have again become active. I argue that, although both objective and subjective probabilities have domains of relevance in QM, their roles are quite

Haskell P. Rosenthal

Several new characterizations of Banach spaces containing a subspace isomorphic to $\ell^1$, are obtained. These are applied to the question of when $\ell^1$ embeds in the injective tensor product of two Banach spaces.

F. Marsiglio, E. van Heumen, A. B. Kuzmenko

A single band optical sum rule derived by Kubo can reveal a novel kind of superconducting state. It relies, however, on a knowledge of the single band contribution from zero to infinite frequency. A number of experiments over the past five years have used this sum rule; their data has been interpreted in support of &#39;kinetic energy-driven superconductivit

Daciberg Lima Gonçalves, John Guaschi

We classify the (finite and infinite) virtually cyclic subgroups of the pure braid groups $P_{n}(RP^2)$ of the projective plane. The maximal finite subgroups of $P_{n}(RP^2)$ are isomorphic to the quaternion group of order 8 if $n=3$, and to $\Z_{4}$ if $n\geq 4$. Further, for all $n\geq 3$, up to isomorphism, the following groups are the infinite virtually

M. A. Majidi, D. G. S. P. Doluweera, B. Moritz, P. R. C. Kent

We demonstrate the existence of ferromagnetism in the Periodic Anderson Model (PAM) at conduction-band filling near a quarter. We show that this ferromagnetism is not supported by Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions but is instead driven by the precursors of charge density wave (CDW) formation in the conduction electron band. To study the effec

Guillaume Thomann, Vincent Artigue

In the world of upper limb prostheses, few companies dominate the majority of the market. They propose different kinds of hand, wrist and elbow prostheses but their control is often difficult to understand by the patients. We have decided to develop new myoelectric prosthetic arm (elbow, wrist and hand) by axing our development on the use of new technologies

Moshe Pollak, Alexander G. Tartakovsky

We consider the simple changepoint problem setting, where observations are independent, iid pre-change and iid post-change, with known pre- and post-change distributions. The Shiryaev-Roberts detection procedure is known to be asymptotically minimax in the sense of minimizing maximal expected detection delay subject to a bound on the average run length to fa