December 2002 arXiv papers — page 9

E. L. Berger, M. Klasen, T. M. P. Tait

Errors in the published version of the paper are corrected, and new figures are provided.

Xiaomin Wang, Max Tegmark, Bhuvnesh Jain, Matias Zaldarriaga

Cosmic shear measurements have now improved to the point where they deserve to be treated on par with CMB and galaxy clustering data for cosmological parameter analysis, using the full measured aperture mass variance curve rather than a mere phenomenological parametrization thereof. We perform a detailed 9-parameter analysis of recent lensing (RCS), CMB (up

Finn Larsen, Asad Naqvi, Seiji Terashima

We present new rolling tachyon solutions describing the classical decay of D-branes. Our methods are simpler than those appearing in recent works, yet our results are exact in classical string theory. The role of pressure in the decay is studied using tachyon profiles with spatial variation. In this case the final state involves an array of codimension one D

M. E. Gehm, S. L. Hemmer, S. R. Granade, K. M. O'Hara

A strongly-attractive, two-component Fermi gas of atoms exhibits universal behavior and should be mechanically stable as a consequence of the quantum mechanical requirement of unitarity. This requirement limits the maximum attractive force to a value smaller than that of the outward Fermi pressure. To experimentally demonstrate this stability, we use all-opt

Sheng Feng, Olivier Pfister

We report the realization of a light source specifically designed for the generation of bright continuous-variable entangled beams and for Heisenberg-limited inteferometry. The source is a nondegenerate, single-mode, continuous-wave optical parametric oscillator in Na:KTP, operated at frequency degeneracy and just above threshold, which is also of interest f

G. Garbarino, A. Parreno, A. Ramos

The main open problem in the physics of Lambda-hypernuclei is the lack of a sound theoretical interpretation of the large experimental values for the ratio G_n/G_p. To approach the problem, we have incorporated a Lambda N-> nN one-meson-exchange model in an intranuclear cascade code for a finite nucleus calculation of the nucleon-nucleon (angular and energy)

P. A. Baikov, K. G. Chetyrkin, J. H. Kühn

We present the analytical calculation of the contribution of order m_q^2 α_s^4 n_f^2 to the absorptive part of the vacuum polarization function of vector currents. This term constitutes an important gauge-invariant part of the full O(m_q^2 alpha_s^4) correction to the total cross-section of e^+ e^- annihilation into hadrons. The results are compared to predi

T. M. Mishonov, S. I. Klenov, E. S. Penev

An explicit expression for the temperature dependence of the specific heat of clean anisotropic-gap superconductors is derived within the weak-coupling BCS approximation. The specific heat is presented as a functional of the superconducting gap on the Fermi surface. The obtained formula interpolates between the correct low coupling jump at T_c and the low te

Chris Dams, Ronald Kleiss

We address the problem that the cross section for the collisions of unstable particles diverges, if calculated by standard methods. This problem is considered for beams much smaller than the decay length of the unstable particle, much larger than the decay length and finally also for pancake- shaped beams. We find that in all cases this problem can be solved

Norihiro Iizuka, Daniel Kabat, Gilad Lifschytz, David A. Lowe

We propose an effective description of 0-brane black holes, in which the black hole is modeled as a gas of non-interacting quasi-particles in the dual quantum mechanics. This simple model is shown to account for many of the static thermodynamic properties of the black hole. It also accounts for dynamical properties, such as the rate at which energy gets ther

C. Barbero, G. Lopez Castro, A. Mariano

We compute the strangeness-conserving double beta decay of $Σ^-$ hyperons, which is the only hadronic system that can undergo such decays. We consider both, the lepton number conserving %$Σ^-\go Σ^++2e^-+2 \barν$ $Σ^-\go Σ^+e^-e^-\barν\barν$ ($ββ_{Σ_{2ν}}$) and the lepton number violating $Σ^-\go Σ^+e^-e^-$ ($ββ_{Σ_{0ν}}$) modes. The branching ratios of thes

David L. Band

Gamma-ray burst detectors are sensitive at different energies, complicating the comparison of the burst populations that they detect. The instrument teams often report their detector sensitivities in their instruments' energy band. I propose that sensitivities be reported as the threshold peak photon flux F_T over the 1-1000 keV energy band for a specifi

P. Valageas, R. Schaeffer, J. Silk

We point out that two problems of observational cosmology, the facts i) that > 60% of the baryonic content of the universe is not observed at z=0 and ii) that the properties of small clusters do not agree with simple expectations, could be closely related. As shown by recent studies, the shock-heating associated with the formation of large-scale structures h

Jaume Garriga, Alex Pomarol

We show that in the Randall-Sundrum model the Casimir energy of bulk gauge fields (or any of their supersymmetric relatives) has contributions that depend logarithmically on the radion. These contributions satisfactorily stabilize the radion, generating a large hierarchy of scales without fine-tuning. The logarithmic behaviour can be understood, in a 4D holo

Gottfried Curio

The membrane instanton superpotential for $M$-theory on the $G_2$ holonomy manifold given by the cone on ${\bf S^3}\x {\bf S^3}$ is given by the dilogarithm and has Heisenberg monodromy group in the quantum moduli space. We compare this to a Heisenberg group action on the type IIA hypermultiplet moduli space for the universal hypermultiplet, to metric correc

Ronald Brown

We outline the main features of the definitions and applications of crossed complexes and cubical $ω$-groupoids with connections. These give forms of higher homotopy groupoids, and new views of basic algebraic topology and the cohomology of groups, with the ability to obtain some non commutative results and compute some homotopy types.

Jacek Dziarmaga, Zbyszek P. Karkuszewski, Krzysztof Sacha

The dark soliton created in a Bose-Einstein condensate becomes grey in course of time evolution because its notch fills up with depleted atoms. This is the result of quantum mechanical calculations which describes output of many experimental repetitions of creation of the stationary soliton, and its time evolution terminated by a destructive density measurem

J. Margueron, P. Chomaz

Asymmetric nuclear matter at sub-saturation densities is shown to present only one type of instabilities. The associated order parameter is dominated by the isoscalar density and so the transition is of liquid-gas type. The instability goes in the direction of a restoration of the isospin symmetry leading to a fractionation phenomenon. These conclusions are

R. P. Malik

We discuss the (dual-)gauge transformations and BRST cohomology for the two (1 + 1)-dimensional (2D) free Abelian one-form and four (3 + 1)-dimensional (4D) free Abelian 2-form gauge theories by exploiting the (co-)BRST symmetries (and their corresponding generators) for the Lagrangian densities of these theories. For the 4D free 2-form gauge theory, we show

P. Giovannangeli, C. P. Korthals Altes

Spatial 't Hooft loops of strength k measure the qualitative change in the behaviour of electric colour flux in confined and deconfined phase of SU (N) gauge theory. They show an area law in the deconfined phase, known analytica lly to two loop order with a ``k-scaling'' law k(N-k). In this paper we comput e the O(g^3) correction to the tension.

Giancarlo Franzese, Roberto Raimondi, Rosario Fazio

We study the Kondo effect in an ultrasmall metallic grain, i.e. small enough to have a discrete energy-level spectrum, by calculating the susceptibility chi of the magnetic impurity. Our quantum Monte Carlo simulations, and analytic solution of a simple model, show that the behavior changes dramatically depending on whether the number of electrons in the gra

A. Crisanti, F. Ritort

This review reports on the research done during the past years on violations of the fluctuation-dissipation theorem (FDT) in glassy systems. It is focused on the existence of a quasi-fluctuation-dissipation theorem (QFDT) in glassy systems and the currently supporting knowledge gained from numerical simulation studies. It covers a broad range of non-stationa

Jean-Michel Courty, A. Heidmann, M. Pinard

We show that quantum noise in very sensitive interferometric measurements such as gravitational-waves detectors can be drastically modified by quantum feedback. We present a new scheme based on active control to lock the motion of a mirror to a reference mirror at the quantum level. This simple technique allows to reduce quantum effects of radiation pressure

B. Pire, L. Szymanowski

We develop an impact representation for the generalized distribution amplitude which describes the exclusive hadronization of a quark-antiquark pair to a pair of mesons. Experiments such as gamma^* gamma -> pi pi and gamma^* N -> pi pi N' are shown to probe the transverse size of the hadronization region of the quark antiquark pair that one can interpret

P. Castorina, A. Iorio, D. Zappala

We study the departures from the classical synchrotron radiation due to noncommutativity of coordinates. We find that these departures are significant, but do not give tight bounds on the magnitude of the noncommutative parameter. On the other hand, these results could be used in future investigations in this direction. We also find an acausal behavior for t

S. A. Trigger

Fokker-Planck equation with the velocity-dependent coefficients is considered for various isotropic systems on the basis of probability transition (PT) approach. This method provides the self-consistent and universal description of friction and diffusion for Brownian particles. Renormalization of the friction coefficient is shown to occur for two dimensional

K. Gallmeister, C. Greiner, Z. Xu

Typically the materialization of high energetic transverse partons to hadronic jets is assumed to occur outside the reaction zone in a relativistic heavy ion collision. In contrast, a quantum mechanical estimate yields a time on the order of only a few fm/c for building up the hadronic wavefunction for jets with typical transverse momenta of pT < 10 GeV as a

Robert V. Harlander, Matthias Steinhauser

This paper describes the fortran program rhad which performs a numerical evaluation of the photon-induced hadronic R-ratio, R(s), related to the cross section for electron-positron annihilation, for a given center-of-mass energy \sqrt{s}. In rhad the state-of-the-art perturbative corrections to R(s) are implemented and the running and decoupling of the stron

Peter Schupp, Josip Trampetic, Julius Wess, Georg Raffelt

In this letter we propose a possible mechanism of left- and right-handed neutrino couplings to photons, which arises quite naturally in non-commutative gauge field theory. We estimate the predicted additional energy-loss in stars induced by space-time non-commutativity. The usual requirement that any new energy-loss mechanism in globular stellar clusters sho

M. A. Ivanov, J. G. Korner, O. N. Pakhomova

In the wake of exploring CP-violation in the decays of B and Bc mesons, we perform the straightforward calculation of their nonleptonic decay rates within a relativistic quark model. We confirm that the decays Bc->Ds antiD0 and Bc->Ds D0 are well suited to extract the Cabibbo-Kobayashi-Maskawa angle γthrough the amplitude relations because their decay widths

Holger Mueller, Claus Braxmaier, Sven Herrmann, Achim Peters

Within the model of a Lorentz violating extension of the Maxwell sector of the standard model, modified light propagation leads to a change of the resonance frequency of an electromagnetic cavity, allowing cavity tests of Lorentz violation. However, the frequency is also affected by a material-dependent length change of the cavity due to a modified Coulomb p

P. Ziesche, K. Pernal, F. Tasnadi

The recently derived sum rules for the scattering phase shifts of the Overhauser geminals (being 2-body-wave functions which parametrize the pair density together with an appropriately chosen occupancy) are generalized to integral equations which allow in principle to calculate the momentum distribution, supposed the phase sifts of the Overhauser geminals ar

David Tong

Non-supersymmetric orbifolds of N=1 super Yang-Mills theories are conjectured to inherit properties from their supersymmetric parent. We examine this conjecture by compactifying the Z_2 orbifold theories on a spatial circle of radius R. We point out that when the orbifold theory lies in the weakly coupled vacuum of its parent, fractional instantons do give r

Uffe Haagerup, Steen Thorbjornsen

In the process of developing the theory of free probability and free entropy, Voiculescu introduced in 1991 a random matrix model for a free semicircular system. Since then, random matrices have played a key role in von Neumann algebra theory (cf. [V8], [V9]). The main result of this paper is the following extension of Voiculescu&#39;s random matrix result:

Peter Coles, Kate Spencer

The dynamical equations describing the evolution of a self-gravitating fluid can be rewritten in the form of a Schrodinger equation coupled to a Poisson equation determining the gravitational potential. This wave-mechanical representation allows an approach to cosmological gravitational instability that has numerous advantages over standard fluid-based metho

A. J. Moreno, J. Colmenero, A. Alegría, C. Alba-Simionesco

We present a neutron scattering investigation on methyl group dynamics in glassy toluene confined in mesoporous silicates of different pore sizes. The experimental results have been analysed in terms of a barrier distribution model, such a distribution following from the structural disorder in the glassy state. Confinement results in a strong decreasing of t

H. Nojiri, H. Kageyama, Y. Ueda, M. Motokawa

The excited state energy spectrum of a two-dimensional dimer system SrCu$_2$(BO$_3$)$_2$ has been investigated by high field ESR. Various types of multiple-triplet bound states-excited singlet, triplet and quintet states are identified, besides two non-degenerated one-triplet excitations. Extremely strong intensity is found for these higher order bound state

Dao-Neng Gao

The CP-violating charge asymmetry in decays K+- --> π+- γγ, which is induced by the electromagnetic penguin operators, has been studied both in thestandard model and in its extensions. Because of a large enhancement of the Wilson coefficients of the electromagnetic penguin operators in the supersymmetric extensions of the standard model, a significant upper

John Schliemann

We analyze the entanglement of SU(2)-invariant density matrices of two spins $\vec S_{1}$, $\vec S_{2}$ using the Peres-Horodecki criterion. Such density matrices arise from thermal equilibrium states of isotropic spin systems. The partial transpose of such a state has the same multiplet structure and degeneracies as the original matrix with eigenvalue of la

J. Bartels, E. Gotsman, E. Levin, M. Lublinsky

We attempt to describe soft hadron interactions in the framework of saturation models, one based upon the Balitsky-Kovchegov non-linear equation and another one due to Golec-Biernat and Wüsthoff. For $pp$, $Kp$, and $πp$ scattering the relevant hadronic wave functions are formulated, and total, elastic cross-sections, and the forward elastic slope are calcul

A. Vuorinen

The pressure of hot QCD has recently been determined to the last perturbatively computable order g^6 ln(g) by Kajantie et al. using three-dimensional effective theories. A similar method is applied here to the pressure in the presence of small but non-vanishing quark chemical potentials, and the result is used to derive the quark number susceptibilities in t

Matthew D. Lehnert, Malcolm Bremer

We have discovered six galaxies with spectroscopically confirmed redshifts of 4.8<z<5.8 in a single 44 square arcminute field imaged deeply in R, I and z-bands. All the spectra show an emission-line in the region around 7000-8400 angstroms with a spectroscopically-detected faint continuum break across the line. These six were drawn from 13 sources with I_AB<

Jamal Sakhr, Rajat K. Bhaduri, Brandon P. van Zyl

We present a numerical study of Riemann&#39;s formula for the oscillating part of the density of the primes and their powers. The formula is comprised of an infinite series of oscillatory terms, one for each zero of the zeta function on the critical line and was derived by Riemann in his paper on primes assuming the Riemann hypothesis. We show that high reso

Changhyun Ahn, Soonkeon Nam

By applying the method of Dijkgraaf-Vafa, we study matrix model related to supersymmetric SO(N_c) gauge theory with N_f flavors of quarks in the vector representation found by Intriligator-Seiberg. By performing the matrix integral over tree level superpotential characterized by light meson fields (mass deformation) in electric theory, we reproduce the exact

K. D. Kokkotas, J. Ruoff, N. Andersson

In this article we show that the, mainly spacetime, w-modes may become unstable in a rotating ultracompact ($R<3M$) relativistic star. We provide results for the axial modes of a rotating star in the slow rotation approximation, and demonstrate that an instability may become active in stars with an ergosphere. These results suggest that the so-called ``ergor

M. C. de Oliveira

A protocol for teleportation of the state of a Bose-Einstein condensate trapped in a three-well potential is developed. The protocol uses hard-sphere cross-collision between the condensate modes as a means of generating entanglement. As Bell state measurement, it is proposed that a homodyne detection of the condensate quadrature is performed through Josephso

Ranabir Das, T. S. Mahesh, Anil Kumar

A new method of quantum state tomography for quantum information processing is described. The method based on two-dimensional Fourier transform technique involves detection of all the off-diagonal elements of the density matrix in a two-dimensional experiment. All the diagonal elements are detected in another one-dimensional experiment. The method is efficie

R. Dandoloff

We show that the geometric phase of Levy-Leblond arises from a low of parallel transport for wave functions and point out that this phase belongs to a new class of geometric phases due to the presence of a quantum potential.

Michael B. Mensky

The restricted-path-integral (RPI) theory of continuous quantum measurements including the evolution of the measured systems and phenomenon of decoherence is reviewed. The measured system is considered as an open quantum system but without usage of any model of the measurement (of the measuring medium or the system&#39;s environment). The propagator of a mea

Erik Sjöqvist, Stefan Filipp

Off-diagonal mixed state phases based upon a concept of orthogonality adapted to unitary evolution and a proper normalisation condition are introduced. Some particular instances are analysed and parallel transport leading to the off-diagonal mixed state geometric phase is delineated. A complete experimental realisation of the off-diagonal mixed state geometr

James R. Bogan

We show there exists an exact and continuous gauge transformation between the Hamilton-Jacobi equation of classical mechanics, and the time-dependent Schrodinger equation of quantum mechanics. The transformation parameter is spin-dependent, and is a function of the quantum potential of Bohmian mechanics.

Ahmed E. Ismail, Gregory C. Rutledge, George Stephanopoulos

The wavelet transform, a family of orthonormal bases, is introduced as a technique for performing multiresolution analysis in statistical mechanics. The wavelet transform is a hierarchical technique designed to separate data sets into sets representing local averages and local differences. Although one-to-one transformations of data sets are possible, the ad

Roger Bruhre-Dawson, Jacques Maillard, Girard Maurel, Jorge Silva

Suspensions of superheated superconducting grains are a detecting composite material. Each grain in the supension is a microcalorimeter with an energy threshold defined by its equatorial magnetic field for a given temperature. The higher the matrix density, the larger the gamma stopping power. For several years, cylindrical cells of such suspensions about 2

L. Duchemin, J. Eggers, C. Josserand

We study the coalescence of two drops of an ideal fluid driven by surface tension. The velocity of approach is taken to be zero and the dynamical effect of the outer fluid (usually air) is neglected. Our approximation is expected to be valid on scales larger than $\ell_ν = ρν^2/σ$, which is $10 nm$ for water. Using a high-precision boundary integral method,

V. G. Mordovskaya, V. N. Oraevsky

In this communication, we examine in situ observations of the magnetic field in the vicinity of Phobos on the &#34;Phobos-2&#34; mission and give some analysis of the data during a unique experiment ``Celestial Mechanics,&#39;&#39; which leads to the support of evidence of the Phobos magnetic field. In particular, it is suggested that the peculiarity of the

Harvey A. Rose

In the strongly damped regime, the convective gain rate for stimulated scatter varies inversely with the plasma wave damping rate. Electron trapping effects reduce the damping but also lead to loss of resonance for large enough amplitude waves. This leads to a gain rate bound and corresponding optimum scattered light frequency and plasma wave amplitude.

Valentin P. Zhigulin, Mikhail I. Rabinovich, Ramon Huerta, Henry D. I. Abarbanel

We study the synchronization of two model neurons coupled through a synapse having an activity-dependent strength. Our synapse follows the rules of Spike-Timing Dependent Plasticity (STDP). We show that this plasticity of the coupling between neurons produces enlarged frequency locking zones and results in synchronization that is more rapid and much more rob

Roberto Assumpcao

Classical, Quantum and Relativistic mechanics elect time and space as fundamentals, extracting the measure of motion -velocity- from this static space-time platform. Conversely, the timelessness of Statistical mechanics computes the physical flow as an evolution of (dynamical) states which, at the end, comes to be what would be denoted as time. Moreover, the

Ahmed E. Ismail, George Stephanopoulos, Gregory C. Rutledge

In this paper, we extend our analysis of lattice systems using the wavelet transform to systems for which exact enumeration is impractical. For such systems, we illustrate a wavelet-accelerated Monte Carlo (WAMC) algorithm, which hierarchically coarse-grains a lattice model by computing the probability distribution for successively larger block spins. We dem

Yury S. Neustadt, Michael B. Partenskii

In linear elastic theory, membrane deformation energy caused by inclusions (e.g., membrane-spanning peptides in lipid bilayers) can be rigorously presented in terms of coupled harmonic oscillators. The general expressions for the corresponding &#34;effective spring constants&#34; are derived here for quite general boundary conditions allowing, e.g., for the

Enrique G. Reyes

Zero curvature formulations, pseudo-potentials, modified versions, ``Miura transformations&#39;&#39;, and nonlocal symmetries of the Korteweg--de Vries, Camassa-- Holm and Hunter--Saxton equations are investigated from an unified point of view: these three equations belong to a two--parameters family of equations ``describing pseudo-spherical surfaces&#39;&#

Enrique G. Reyes

Hierarchies of evolution equations of pseudo-spherical type are introduced, generalizing the notion of a single equation describing pseudo-spherical surfaces due to S.S. Chern and K. Tenenblat, and providing a connection between differential geometry and the study of hierarchies of equations which are the integrability condition of $sl(2,{\bf R})$--valued li

Anca Visinescu, D. Grecu

The discrete self-trapping equation (DST) represents an useful model for several properties of one-dimensional nonlinear molecular crystals. The modulational instability of DST equation is discussed from a statistical point of view, considering the oscillator amplitude as a random variable. A kinetic equation for the two-point correlation function is written

Frank W. Nijhoff, Sian Puttock

A general structure is developed from which a system of integrable partial difference equations is derived generalising the lattice KdV equation. The construction is based on an infinite matrix scheme with as key ingredient a (formal) elliptic Cauchy kernel. The consistency and integrability of the lattice system is discussed as well as special solutions and

Thomas Guhr, Heiner Kohler

The previous supersymmetric generalization of the unitary Harish--Chandra integral prompted the conjecture that the Harish--Chandra formula should extend to all classical supergroups. We prove this conjecture for the unitary orthosymplectic supergroup UOSp(k_1/2k_2). To this end, we construct and solve an eigenvalue equation.

Thomas Guhr, Heiner Kohler

We construct Gelfand--Tzetlin coordinates for the unitary orthosymplectic supergroup UOSp(k_1/2k_2). This extends a previous construction for the unitary supergroup U(k_1/k_2). We focus on the angular Gelfand--Tzetlin coordinates, i.e. our coordinates stay in the space of the supergroup. We also present a generalized Gelfand pattern for the supergroup UOSp(k

Daniel Lenz, Norbert Peyerimhoff, Ivan Veselic&#39;

We study ergodic random Schr&#34;odinger operators on a covering manifold, where the randomness enters both via the potential and the metric. We prove measurability of the random operators, almost sure constancy of their spectral properties, the existence of a selfaveraging integrated density of states and a Šubin type trace formula.

Daniel Lenz, Norbert Peyerimhoff, Ivan Veselic&#39;

We consider a random family of Schrödinger operators on a cover $X$ of a compact Riemannian manifold $M = X/Γ$. We present several results on their spectral theory, in particular almost sure constancy of the spectral components and existence and non-randomness of an integrated density of states. We also sketch a groupoid based general framework which allows

J. Xin

We study the asymptotics of front speeds of the reaction-diffusion equations with Kolmogorov-Petrovsky-Piskunov (KPP) nonlinearity and zero mean stationary ergodic Gaussian shear advection on the entire plane. By exploiting connections of KPP front speeds with the almost sure Lyapunov exponents of the parabolic Anderson problem, and with the homogenized Hami

Yi-shi Duan, Peng-ming Zhang

We define a new one form H^A based on the second fundamental tensor H^abA, the Gauss-Bonnet-Chern form can be novelly expressed with this one-form. Using the phi-mapping theory we find that the Gauss-Bonnet-Chern density can be expressed in terms of the delta-function and the relationship between the Gauss-Bonnet-Chern theorem and Hopf-Poincare theorem is gi

Simon A. King

Any two triangulations of a closed surface with the same number of vertices can be transformed into each other by a sequence of regular flips, provided the number of vertices exceeds a number N depending on the surface. Examples show that in general N is bigger than the minimal number of vertices of a triangulation. The existence of N was known, but no estim

Joel Bellaiche, Gaetan Chenevier

We use $p$-adic families of automorphic forms for an unitary group in three variables, containing some non-tempered forms constructed by Rogawski, to prove some cases of the Bloch-Kato conjectures.

G. M. Molchan, A. V. Khokhlov

We consider the integral of fractional Brownian motion (IFBM) and its functionals $ξ_T$ on the intervals $(0,T)$ and $(-T,T)$ of the following types: the maximum $M_T$, the position of the maximum, the occupation time above zero etc. We show how the asymptotics of $P(ξ_T<1)=p_T, T\to \infty$, is related to the Hausdorff dimension of Lagrangian regular points

Alejandro Adem

We survey some results concerning finite group actions on products of spheres.

Dimitri Gioev

This is a detailed version of the paper math.FA/0212273. The main motivation for this work was to find an explicit formula for a &#34;Szego-regularized&#34; determinant of a zeroth order pseudodifferential operator (PsDO) on a Zoll manifold. The idea of the Szego-regularization was suggested by V. Guillemin and K. Okikiolu. They have computed the second term

Dimitri Gioev

The main motivation for this work was to find an explicit formula for a &#34;Szego-regularized&#34; determinant of a zeroth order pseudodifferential operator (PsDO) on a Zoll manifold. The idea of the Szego-regularization was suggested by V. Guillemin and K. Okikiolu. They have computed the second term in a Szego type expansion on a Zoll manifold of an arbit

Ronald Brown, Philip J. Higgins

The main result is that the fundamental groupoid of the orbit space of a discontinuous action of a discrete group on a Hausdorff space which admits a universal cover is the orbit groupoid of the fundamental groupoid of the space. We also describe work of Higgins and of Taylor which makes this result usable for calculations. As an example, we compute the fund

Dmitri Panov

There exists a smooth foliation with 3 singular points on the two-dimensional torus such that any lifting of a leaf of this foliation on the universal covering of the torus is a dense subset of the covering.

Emeric Deutsch, Aaron Robertson, Dan Saracino

Define $I_n^k(α)$ to be the set of involutions of $\{1,2,...,n\}$ with exactly $k$ fixed points which avoid the pattern $α\in S_i$, for some $i \geq 2$, and define $I_n^k(\emptyset;α)$ to be the set of involutions of $\{1,2,...,n\}$ with exactly $k$ fixed points which contain the pattern $α\in S_i$, for some $i \geq 2$, exactly once. Let $i_n^k(α)$ be the nu

Ieke Moerdijk

This is an introduction to gerbes for topologists, with emphasis on non-abelian cohomology.

Ludwik Dabrowski

A list of known quantum spheres of dimension one, two and three is presented.

Andreas Klein, Markus Wessler

The aim of this paper is the determination of the largest $n$-dimensional polytope with $n+3$ vertices of unit diameter. This is a special case of a more general problem proposed by Graham.

C. R. E. Raja

We consider a class of measures called autophage which was introduced and studied by Szekely for measures on the real line. We show that the autophage measures on finite-dimensional vector spaces over real or p-adic field are infinitely divisible without idempotent factors and are absolutely continuous with bounded continuous density. We also show that certa

Kenji Matsuki, Martin Olsson

We associate to a pair $(X,D)$, consisting of a smooth scheme with a divisor $D\in \text{Div}(X)\otimes \mathbb{Q}$ whose support is a divisor with normal crossings, a canonical Deligne--Mumford stack over $X$ on which $D$ becomes integral. We then reinterpret the Kawamata--Viehweg vanishing theorem as Kodaira vanishing for stacks.

Morihiko Saito

For a smooth complex projective variety X defined over a number field, we have filtrations on the Chow groups depending of the choice of realizations. If the realization consists of mixed Hodge structure without any additional structure, we can show that the obtained filtration coincides with the filtration of Green and Griffiths, assuming the Hodge conjectu

Marc A. Rieffel

Let $\ell$ be a length function on a group $G$, and let $M_{\ell}$ denote the operator of pointwise multiplication by $\ell$ on $\bell^2(G)$. Following Connes, $M_{\ell}$ can be used as a ``Dirac&#39;&#39; operator for $C_r^*(G)$. It defines a Lipschitz seminorm on $C_r^*(G)$, which defines a metric on the state space of $C_r^*(G)$. We investigate whether th

Alex Kumjian, David Pask

An action of ${\mathbb Z}^k$ is associated to a higher rank graph $Λ$ satisfying a mild assumption. This generalises the construction of a topological Markov shift arising from a nonnegative integer matrix. We show that the stable Ruelle algebra of $Λ$ is strongly Morita equivalent to $C^*(Λ)$. Hence, if $Λ$ satisfies the aperiodicity condition, the stable R

Marcus Berg, Michael Haack, Henning Samtleben

In Calabi-Yau fourfold compactifications of M-theory with flux, we investigate the possibility of partial supersymmetry breaking in the three-dimensional effective theory. To this end, we place the effective theory in the framework of general N=2 gauged supergravities, in the special case where only translational symmetries are gauged. This allows us to extr

Korkut Bardakci, Charles B. Thorn

We present an improved version of our earlier work on summing the planar graphs in phi^3 field theory. The present treatment is also based on our world sheet formalism and the mean field approximation, but it makes use of no further approximations. We derive a set of equations between the expectation values of the world sheet fields, and we investigate them

Jan de Boer, Eric Gimon, Koenraad Schalm, Jeroen Wijnhout

An indication for the existence of a collective Myers solution in the non-abelian D0-brane Born-Infeld action is the presence of a tachyonic mode in fluctuations around the standard diagonal background. We show that this computation for non-abelian D0-branes in curved space has the geometric interpretation of computing the eigenvalues of the geodesic deviati

Jürg Käppeli

We present a spacetime diffeomorphism invariant formulation of the geodesic approximation to soliton dynamics.

Edward Witten

String theory avoids the ultraviolet infinities that arise in trying to quantize gravity. It is also more predictive than conventional quantum field theory, one aspect of this being the way that it contributed to the emergence of the concept of ``supersymmetry&#39;&#39; of particle interactions. There are hints from the successes of supersymmetric unified th

Bernard de Wit

These notes are based on lectures presented at the 2001 Les Houches Summerschool ``Unity from Duality: Gravity, Gauge Theory and Strings&#39;&#39;

L. R. Huiszoon

The simple current construction of orientifolds based on rational conformal field theories is reviewed. When applied to SO(16) level 1, one can describe all ten-dimensional orientifolds in a unified framework.

J. Teschner

This note announces the proof of a conjecture of H. Verlinde, according to which the spaces of Liouville conformal blocks and the Hilbert spaces from the quantization of the Teichmüller spaces of Riemann surfaces carry equivalent representations of the mapping class group. This provides a basis for the geometrical interpretation of quantum Liouville theory i

Shmuel Elitzur, Amit Giveon, Eliezer Rabinovici

Big bang/crunch curvature singularities in exact CFT string backgrounds can be removed by turning on gauge fields. This is described within a family of {SL(2)xSU(2)xU(1)_x}/{U(1)xU(1)} quotient CFTs. Uncharged incoming wavefunctions from the ``whiskers&#39;&#39; of the extended universe can be fully reflected if and only if a big bang/crunch curvature singul

Jose L. Vazquez-Bello

It is well known that BRST symmetry plays a fundamental role in constructing quantum gauge theories. Yet, at the classical level, it constitutes the modern language to study constrained systems. First, this letter reviews the Sp(2) covariant quantisation of gauge theories, so that the geometrical interpretation of gauge theories in terms of quasi-principal f

Bernard de Wit, Henning Samtleben, Mario Trigiante

A consistent gauging of maximal supergravity requires that the T-tensor transforms according to a specific representation of the duality group. The analysis of viable gaugings is thus amenable to group-theoretical analysis, which we explain and exploit for a large variety of gaugings. We discuss the subtleties in four spacetime dimensions, where the ungauged

E. Megias, E. Ruiz Arriola, L. L. Salcedo

The lower order terms of the heat kernel expansion at coincident points are computed in the context of finite temperature quantum field theory for flat space-time and in the presence of general gauge and scalar fields which may be non Abelian and non stationary. The computation is carried out in the imaginary time formalism and the result is fully consistent

L. Andrianopoli, R. D&#39;Auria, S. Ferrara, M. A. Lledo&#39;

In the context of N=2 supergravity we explain the occurrence of partial super-Higgs with vanishing vacuum energy and moduli stabilization in a model suggested by superstring compactifications on type IIB orientifolds with 3-form fluxes. The gauging of axion symmetries of the quaternionic manifold, together with the use of degenerate symplectic sections for s