July 2004 arXiv papers — page 3

Philip B. Allen

Goetze and Woelfle (GW) wrote the conductivity in terms of a memory function M as (ine2/m)/(omega+M(omega)), where M=i/tau in the Drude limit. The analytic properties of -M are the same as those of the self-energy of a retarded Green's function. In the approximate treatment of GW, -M closely resembles a self-energy, with differences, e.g., the imaginary

Y. Mambrini, C. Munoz

We carry out a comparison between different kinds of experiments for the detection of neutralino dark matter. In particular, we compare the theoretical predictions for the direct detection of these particles, through their elastic scattering on target nuclei through nuclear recoils, with those for their indirect detection through the gamma rays produced by t

M. F. Bietenholz, N. Bartel, M. P. Rupen

We report on VLBI observations of M81*, the northwest-southeast oriented nuclear core-jet source of the spiral galaxy M81, at five different frequencies between 1.7 and 14.8 GHz. By phase referencing to supernova 1993J we can accurately locate the emission region of M81* in the galaxy's reference frame. Although the emission region's size decreases w

Dorin Ervin Dutkay, Palle E. T. Jorgensen

Let X be a compact Hausdorff space. We study finite-to-one mappings r:X->X, onto X, and measures on the corresponding projective limit space X_\infinity(r). We show that the invariant measures on X_\infinity(r) correspond in a one-to-one fashion to measures on X which satisfy two identities. Moreover, we identify those special measures on X_\infinity(r) whic

N. Michel, W. Nazarewicz, M. Ploszajczak

The shell model in the complex k-plane (the so-called Gamow Shell Model) has recently been formulated and applied to structure of weakly bound, neutron-rich nuclei. The completeness relations of Newton and Berggren, which apply to the neutron case, are strictly valid for finite-range potentials. However, for long-range potentials, such as the Coulomb potenti

Eric Falcon, Bernard Castaing

We show how a simple laboratory experiment can illustrate certain electrical transport properties of metallic granular media. At a low critical imposed voltage, a transition from an insulating to a conductive state is observed. This transition comes from an electro-thermal coupling in the vicinity of the microcontacts between grains where microwelding occurs

Robert Raussendorf, Sergey Bravyi, Jim Harrington

We describe a phase transition for long-range entanglement in a three-dimensional cluster state affected by noise. The partially decohered state is modeled by the thermal state of a suitable Hamiltonian. We find that the temperature at which the entanglement length changes from infinite to finite is nonzero. We give an upper and lower bound to this transitio

Antonio Di Lisi, Silvio De Siena, Fabrizio Illuminati, David Vitali

We introduce an efficient, quasideterministic scheme to generate maximally entangled states of two atomic ensembles. The scheme is based on quantum nondemolition measurements of total atomic populations and on adiabatic quantum feedback conditioned by the measurements outputs. The high efficiency of the scheme is tested and confirmed numerically for ideal ph

V. Moretti, N. Pinamonti

Local scalar QFT (in Weyl algebraic approach) is constructed on degenerate semi-Riemannian manifolds corresponding to Killing horizons in spacetime. Covariance properties of the $C^*$-algebra of observables with respect to the conformal group $PSL(2,\bR)$ are studied.It is shown that, in addition to the state studied by Guido, Longo, Roberts and Verch for bi

Darren T. Grasso

We apply heat kernel techniques in N=1 superspace to compute the one-loop effective action to order $F^5$ for chiral superfields coupled to a non-Abelian super Yang-Mills background. The results, when combined with those of hep-th/0210146, yield the one-loop effective action to order $F^5$ for any N=2 super Yang-Mills theory coupled to matter hypermultiplets

Klaus Behrndt, Mirjam Cvetic

We study conditions on general fluxes of massive Type IIA supergravity that lead to four-dimensional backgrounds with N = 1 supersymmetry. We derive these conditions in the case of SU(3)- as well as SU(2)-structures. SU(3)-structures imply that the internal space is constrained to be a nearly Kähler manifold with all the turned on fluxes, and the negative co

Markus Schmidmeier

In 1934, Garrett Birkhoff has shown that the number of isomorphism classes of finite metabelian groups of order $p^{22}$ tends to infinity with $p$. More precisely, for each prime number $p$ there is a family $(M_λ)_{λ=0,...,p-1}$ of indecomposable and pairwise nonisomorphic metabelian $p$-groups of the given order. In this manuscript we use recent results o

C. Stock, S. Wakimoto, R. J. Birgeneau, S. Danilkin

We present elastic neutron scattering results at high magnetic fields for Mg-doped CuGeO$_{3}$. For low magnesium concentrations, where a spin-Peierls phase is present, we find an enhancement of the long range antiferromagnetic order in the structural incommensurate phase induced by a high magnetic field. In the incommensurate phase, the Néel temperature inc

Andrei Kryjevski, Daisuke Yamada

We compute free energy of quark matter at asymptotically high baryon number density in the presence of non zero strange quark mass including dynamics of pseudo Nambu-Goldstone bosons due to chiral symmetry breaking, extending previously existing analysis based on perturbative expansion in $m_s^2/4μΔ.$ We demonstrate that the CFL$K^0$ state has lower free ene

Dan Hooper, Andrew Taylor, Subir Sarkar

As ultra-high energy cosmic ray protons propagate through the universe, they undergo photo-meson interactions with the cosmic microwave background, generating the `cosmogenic' neutrino flux. If a substantial fraction of the cosmic ray primaries are heavy nuclei rather than protons, however, they would preferentially lose energy through photo-disintegrati

F. J. Botella, M. Nebot, O. Vives

We use a new weak basis invariant approach to classify all the observable phases in any extension of the Standard Model (SM). We apply this formalism to determine the invariant CP phases in a simplified version of the Minimal Supersymmetric SM with only three non-trivial flavour structures. We propose four experimental measures to fix completely all the obse

B. El-Bennich

It is argued that in the antiproton-proton annihilation into two mesons $\bar pp\longrightarrow m_1 m_2$, the origin of different restrictive angular momentum selection rules commonly obtained for planar annihilation diagrams $A2$ and for non-planar rearrangement diagrams $R2$ lies in the omission of momentum transfer between an annihilated antiquark-quark p

C. Biggio, M. Quiros

In orbifold gauge theories localized tadpoles can be radiatively generated at the fixed points where U(1) subgroups are conserved. If the Standard Model Higgs fields are identified with internal components of the bulk gauge fields (Higgs-gauge unification) in the presence of these tadpoles the Higgs mass becomes sensitive to the UV cutoff and electroweak sym

Dongsu Bak, Yoshifumi Hyakutake, Seok Kim, Nobuyoshi Ohta

We give a geometric interpretation of the entropy of the supertubes with fixed conserved charges and angular momenta in two different approaches using the DBI action and the supermembrane theory. By counting the geometrically allowed microstates, it is shown that both the methods give consistent result on the entropy. In doing so, we make the connection to t

N. Fornengo, L. Pieri, S. Scopel

We discuss the gamma-ray signal from dark matter annihilation in our Galaxy and in external objects, namely the Large Magellanic Cloud, the Andromeda Galaxy (M31) and M87. We derive predictions for the fluxes in a low energy realization of the Minimal Supersymmetric Standard Model and compare them with current data from EGRET, CANGAROO-II and HEGRA and with

A. Carati

For a dynamical system far from equilibrium, one has to deal with empirical probabilities defined through time-averages, and the main problem is then how to formulate an appropriate statistical thermodynamics. The common answer is that the standard functional expression of Boltzmann-Gibbs for the entropy should be used, the empirical probabilities being subs

Wei-Li Lee, S. Watauchi, V. L. Miller, R. J. Cava

In a ferromagnet, an anomalous-Hall heat current, given by the off-diagonal Peltier term $α_{xy}$, accompanies the anomalous Hall current. By combining Nernst, thermopower and Hall experiments, we have measured how $α_{xy}$ varies with hole density and lifetime $τ$ in $\rm CuCr_2Se_{4-x}Br_x$. At low temperatures $T$, we find that $α_{xy}$ is independent of

Feng Yuan, Wei Cui, Ramesh Narayan

Multi-wavelength observations of the black hole X-ray binary XTE J1118+480 have offered abundant spectral and timing information about the source, and have thus provided serious challenges to theoretical models. We propose a coupled accretion-jet model to interpret the observations. We model the accretion flow as an outer standard thin accretion disk truncat

Robert L. Bryant

A Finsler space is said to be geodesically reversible if each oriented geodesic can be reparametrized as a geodesic with the reverse orientation. A reversible Finsler space is geodesically reversible, but the converse need not be true. In this note, building on recent work of LeBrun and Mason, it is shown that a geodesically reversible Finsler metric of cons

T. G. Birthwright, E. W. N. Glover, P. Marquard

We compute the master integrals for massless two-loop vertex graphs with three off-shell legs. These master integrals are relevant for the QCD corrections to H to V*V* (where V = W, Z) and for two-loop studies of the triple gluon (and quark-gluon) vertex. We employ the differential equation technique to provide series expansions in epsilon for the various ma

David Vignolles, Alain Audouard, Marc Nardone, Luc Brossard

Interlayer magnetoresistance of the Bechgaard salt (TMTSF)$_2$NO$_3$ is investigated up to 50 teslas under pressures of a few kilobars. This compound, the Fermi surface of which is quasi two-dimensional at low temperature, is a semi metal under pressure. Nevertheless, a field-induced spin density wave is evidenced at 8.5 kbar above $\sim$ 20 T. This state is

Iker Zuriguel, Angel Garcimartín, Diego Maza, Luis A. Pugnaloni

In this work we present an experimental study of the jamming that stops the free flow of grains from a silo discharging by gravity. When the outlet size is not much bigger than the beads, granular material jams the outlet of the container due to the formation of an arch. Statistical data from the number of grains fallen between consecutive jams are presented

Yun-Song Piao

Recently, the notion that the number of vacua is enormous has received increased attentions, which may be regarded as a possible anthropical explanation to incredible small cosmological constant. Further, a dynamical mechanisms to implement this possibility is required. We show in an operable model of cyclic universe that the universe can experience many cyc

Dietmar Klemm, Luciano Vanzo

In these lectures we give a review of recent attempts to understand quantum gravity on de Sitter spaces. In particular, we discuss the holographic correspondence between de Sitter gravity and conformal field theories proposed by Hull and by Strominger, and how this may be reconciled with the finite-dimensional Hilbert space proposal by Banks and Fischler. Fu

Thorsten Ohl, Jurgen Reuter

Extensions of the Standard Model of elementary particle physics to noncommutative geometries are proposed by string models. Independent of this motivation, one may consider such a model as an effective field theory with higher-dimensional operators containing an antisymmetric rank-2 background field. We study the signals of such a Noncommutative Standard Mod

J. Peguiron, M. Grifoni

A duality relation between the long-time dynamics of a quantum Brownian particle in a tilted ratchet potential and a driven dissipative tight-binding model is reported. It relates a situation of weak dissipation in one model to strong dissipation in the other one, and vice versa. We apply this duality relation to investigate transport and rectification in ra

Massimo Ostilli, Carlo Presilla

On the base of a Feynman-Kac--type formula involving Poisson stochastic processes, recently a Monte Carlo algorithm has been introduced, which describes exactly the real- or imaginary-time evolution of many-body lattice quantum systems. We extend this algorithm to the exact simulation of time-dependent correlation functions. The techniques generally employed

P. Lava, J. Ryckebusch, B. Van Overmeire, S. Strauch

Polarization-transfer components for 4He(\vec{e},e'\vec{p})3H and 16O(\vec{e},e'\vec{p})15N are computed within the relativistic multiple-scattering Glauber approximation (RMSGA). The RMSGA framework adopts relativistic single-particle wave functions and electron-nucleon couplings. The predictions closely match those of a relativistic plane-wave mode

D. Indumathi, M. V. N. Murthy

It is by now established that neutrinos mix, have (different) non-zero masses, and therefore oscillate. The oscillation parameters themselves, however, are not all well-known. An open problem is that of the neutrino mass hierarchy. We study the possibility of determining the neutrino mass hierarchy with atmospheric neutrinos using an iron calorimeter detecto

Naomi Ota, Kazuhisa Mitsuda

We present a uniform analysis of the ROSAT HRI and the ASCA GIS/SIS data for 79 distant clusters of galaxies in the redshift range, 0.1 < z < 0.82 to study the global structures of the intracluster medium. We have constructed an X-ray catalog consisting of the largest sample of clusters in the redshift range for which pointed X-ray observations were carried

A. Misra, A. Nanda

We study the number of flux vacua for type IIB string theory on an orientifold of the Calabi-Yau expressed as a hypersurface in WCP^4[1,1,2,2,6] by evaluating a suitable integral over the complex-structure moduli space as per the conjecture of Douglas and Ashok. We show that away from the singular conifold locus, one gets a power law, and that the (neighborh

I. B. Khriplovich

Contrary to the wide-spread belief, the correspondence principle does not dictate any relation between the asymptotics of quasinormal modes and the spectrum of quantized black holes. Moreover, this belief is in conflict with simple physical arguments.

Y. H. Hou, Y. P. Jing, D. H. Zhao, G. Börner

We have accurately measured the bispectrum for four scale-free models of structure formation with the spectral index $n=1$, 0, -1, and -2. The measurement is based on a new method that can effectively eliminate the alias and numerical artifacts, and reliably extend the analysis into the strongly non-linear regime. The work makes use of a set of state-of-the

Y. -h. Taguchi, Y. Oono

Motivation:Microarray experiments result in large scale data sets that require extensive mining and refining to extract useful information. We demonstrate the usefulness of (nonmetric) multidimensional scaling (MDS) method in analyzing a large number of genes. Applying MDS to the microarray data is certainly not new, but the existing works are all on small n

Kazuo Fujikawa

We comment on what the naturalness argument of &#39;t Hooft implies for a minimal extension of the standard model which incorporates right-handed neutrinos with generic mass terms. If this Lagrangian is taken as a low energy effective theory, the idea of pseudo-Dirac neutrinos with very small masses is consistent with the naturalness argument of &#39;t Hooft

W. Fan, X. G. Gong

Based on Density Functional Theory with no-collinear-magnetism formulations, we have calculated magnetic anisotropy of supported Ni chains. Our results indicate that the magnetic anisotropy is closely related to orbital quenching. The easiest magnetized axis changes from parallel to perpendicular to the Ni chains once they absorb on the surface. Our results

W. Fan, X. G. Gong

We calculate the magnetism of 3d transition metals on Au(110)-(1$\times$2) surface and Au(111) surface based on the Density Functional Theory. Our results show that the spin moments of the two-side elements of the 3d group such as Ti, V, Co and Ni decrease greater values than those of the middle elements such as Cr and Mn when they absorb on the surfaces. Ou

Andrei Kryjevski, Thomas Schaefer

We study the effective field theory for fermions in the color-flavor locked (CFL) phase of high density QCD. The effective theory contains a flavor nonet of baryons interacting with a nonet of pseudoscalar Goldstone bosons as well as a singlet scalar Goldstone boson. The theory is similar to chiral perturbation theory in the one-baryon sector. We explain how

Frans Pretorius

A new numerical scheme to solve the Einstein field equations based upon the generalized harmonic decomposition of the Ricci tensor is introduced. The source functions driving the wave equations that define generalized harmonic coordinates are treated as independent functions, and encode the coordinate freedom of solutions. Techniques are discussed to impose

Vadim V. Borzov, Eugene V. Damaskinsky

We are continuing here the study of generalized coherent states of Barut-Girardello type for the oscillator-like systems connected with the given set of orthogonal polynomials. In this work we construct the family of coherent states associated with discrete $q$-Hermite polynomials of the II-type and prove the over-completeness of this family of states by con

Gregg Jaeger

A class of self-similar sets of entangled quantum states is introduced, for which a recursive definition is provided. These sets, the &#34;Bell gems,&#34; are defined by the subsystem exchange symmetry characteristic of the Bell states. Each Bell gem is shown to be an orthonormal basis of maximally entangled elements. A non-trivial example Bell gem is presen

R. García--Maraver, R. Corbalán, K. Eckert, S. Rebić

A single three-level atom driven by a longitudinal mode of a high-Q cavity is used to implement two-qubit quantum phase gates for the intracavity field. The two qubits are associated to the zero-and one-photon Fock states of each of the two opposite circular polarization states of the field. The three-level atom yields the conditional phase gate provided the

Joseph Kimeu, Roland Mai, Kingshuk Majumdar

We have applied the variational $R$-matrix method to calculate the reflection and tunneling probabilities of particles tunneling through one-dimensional potential barriers for five different types of potential profiles -- truncated linear step, truncated exponential step, truncated parabolic, bell-shaped, and Eckart. Our variational results for the transmiss

David Perez-Garcia

We give a short proof of the cross norm characterization of separability due to O. Rudolph and show how its computation, for a fixed chosen error, can be reduced to a linear programming problem whose dimension grows polynomially with the inverse of the error.

Nicolas Treps, Vincent Delaubert, Agnes Maitre, Jean-Michel Courty

We consider the general problem of the quantum noise in a multipixel measurement of an optical image. We first give a precise criterium in order to characterize intrinsic single mode and multimode light. Then, using a transverse mode decomposition, for each type of possible linear combination of the pixels&#39; outputs we give the exact expression of the det

Armin Uhlmann

Antilinearity is quite natural in bipartite quantum systems. There is a one-to-one correspondence between vectors and certain antilinear maps, here called EPR-maps. Some of their properties and uses, including the factorization of quantum teleportation maps, is explained. There is an elementary link to twisted Kronecker products and to the modular objects of

XiaoGuang Wang

We solve the eigenvalue problem of the five-qubit anisotropic Heisenberg model, without use of Bethe&#39;s Ansatz, and give analytical results for entanglement and mixedness of two nearest-neighbor qubits. The entanglement takes its maximum at Delta= (Delta>1) for the case of zero (finite) temperature with Delta being the anisotropic parameter. In contrast,

Zheng-Wei Zhou, Bo Yu, Xingxiang Zhou, Marc J. Feldman

We investigate how to concatenate different decoherence-free subspaces (DFSs) to realize scalable universal fault-tolerant quantum computation. Based on tunable $XXZ$ interactions, we present an architecture for scalable quantum computers which can fault-tolerantly perform universal quantum computation by manipulating only single type of parameter. By using

Yangjian Cai, Shiyao Zhu

We present a theoretical study of ghost imaging by using blackbody radiation source. A Gaussian thin lens equation for the ghost imaging, which depends on both paths, is derived. The dependences of the visibility and quality of the image on the transverse size and temperature of the blackbody are studied. The main differences between the ghost imaging by usi

Paolo Amore, Jorge Lopez

We apply a method recently devised by one of the authors to obtain an approximate analytical formula for the spectrum of a quantum anharmonic potential. Due to its general features the method can be applied with minimal effort to general quantum potentials thus allowing very promising applications.

Changyu Hu, Xiang Li, Jie Liang

Motivation. Protein design aims to identify sequences compatible with a given protein fold but incompatible to any alternative folds. To select the correct sequences and to guide the search process, a design scoring function is critically important. Such a scoring function should be able to characterize the global fitness landscape of many proteins simultane

T. Andrew Binkowski, Bhaskar DasGupta, Jie Liang

Circular permutation connects the N and C termini of a protein and concurrently cleaves elsewhere in the chain, providing an important mechanism for generating novel protein fold and functions. However, their in genomes is unknown because current detection methods can miss many occurances, mistaking random repeats as circular permutation. Here we develop a m

John W. Cain, Elena G. Tolkacheva, David G. Schaeffer, Daniel J. Gauthier

Action potential duration (APD) restitution, which relates APD to the preceding diastolic interval (DI), is a useful tool for predicting the onset of abnormal cardiac rhythms. However, it is known that different pacing protocols lead to different APD restitution curves (RCs). This phenomenon, known as APD rate-dependence, is a consequence of memory in the ti

Rui Lian, Dmitri A. Oulianov, Ilya A. Shkrob, Robert A. Crowell

The picosecond geminate recombination kinetics for hydrated electrons generated by 200 nm two photon absorption (12.4 eV total energy) has been measured in both light and heavy water. The geminate kinetics are observed to be almost identical in both H2O and D2O. Kinetic analysis based upon the independent reaction time approximation indicates that the averag

Valerio Lucarini, Sandro Calmanti, Vincenzo Artale

We reconsider the problem of the stability of the thermohaline circulation as described by a two-dimensional Boussinesq model with mixed boundary conditions. We determine how the stability properties of the system depend on the intensity of the hydrological cycle. We define a two-dimensional parameters&#39; space descriptive of the hydrology of the system an

Dipti Banerjee

The dielectric property $(2\times2)$ of the anisotropic optical medium is found out considering the polarized photon as two component spinor of spherical harmonics.The Geometric Phase of single polarized photon has been evaluated in two ways. The phase two-form of the dielectric matrix through a twist and the Pancharatnam phase (GP) through the change of ang

Valerio Lucarini, Teresa Nanni, Antonio Speranza

We present an analysis of seasonal cycle of the last 50 years of records of surface temperature in Italy. We consider two data sets which synthesize the surface temperature fields of Northern and Southern Italy. Such data sets consist of records of daily maximum and minimum temperature. We compute the best estimate of the seasonal cycle of the variables cons

Natalia Panafidina, Zinovy Malkin

Weekly coordinate time series for the all EPN (European Permanent GPS Network) stations for the period of observations beginning from GPS week 834 was obtained by a reprocessing of the official EPN solutions. Comparison of this series with EPN Central Bureau (EPN CB) and the previous IAA two-year solution for selected EPN stations obtained by reprocessing of

G. G. Kozlov

It is shown that the monochromatic optical wave propagating through the medium with linear birefringence in presence of a signal electromagnetic wave (whose wavelength is equal to the polarization beats length), displays Faraday rotation having the frequency of the signal wave and unsuppressed by linear birefringence. The effect is resonant with respect to t

I. G. Shukhman, V. B. Levinski

The evolution of a small-amplitude localized vortex disturbance in an unbounded shear flow with the linear velocity profile is investigated. Based on the exact solution of the initial problem for basic flow, a revision is made of the theoretical approach (suggested by Levinski (1991) and subsequently further developed in a series of other publications) in wh

J. Terasaki, J. Engel, M. Bender, J. Dobaczewski

We use the canonical Hartree-Fock-Bogoliubov basis to implement a completely self-consistent quasiparticle-random-phase approximation with arbitrary Skyrme energy density functionals and density-dependent pairing functionals. The point of the approach is to accurately describe multipole strength functions in spherical even-even nuclei, including weakly-bound

A. Leviatan

Relativistic symmetries of the Dirac Hamiltonian with a mixture of spherically symmetric Lorentz scalar and vector potentials, are examined from the point of view of supersymmetric quantum mechanics. The cases considered include the Coulomb, pseudospin and spin limits relevant, respectively, to atoms, nuclei and hadrons.

Omar Benhar, Nicola Farina

In the impulse approximation regime the nuclear response to a weakly interacting probe can be written in terms of the measured nucleon structure fuctions and the target spectral function, yielding the energy and momentum distribution of the constituent nucleons. We discuss a calculation of charged current neutrino-oxygen interactions in the quasielastic chan

Eed M. Darwish

Polarization observables of the three charge states of the pion for the $γd\toπNN$ reaction with polarized photon beam and/or oriented deuteron target are evaluated over the whole $Δ$(1232)-resonance region adopting a nonrelativistic model based on time-ordered perturbation theory. Results for the $π$-meson spectra, linear photon asymmetry, vector and tensor

L. Ts. Adzhemyan, J. Honkonen, M. V. Kompaniets, A. N. Vasil&#39;ev

An improved $\eps$ expansion in the $d$-dimensional ($d > 2$) stochastic theory of turbulence is constructed at two-loop order which incorporates the effect of pole singularities at $d \to 2$ in coefficients of the $\eps$ expansion of universal quantities. For a proper account of the effect of these singularities two different approaches to the renormalizati

Pavel Kalugin

Quasiperiodic patterns described by polyhedral &#34;atomic surfaces&#34; and admitting matching rules are considered. It is shown that the cohomology ring of the continuous hull of such patterns is isomorphic to that of the complement of a torus $T^N$ to an arrangement $A$ of thickened affine tori of codimension two. Explicit computation of Betti numbers for

T. G. Elizarova, I. S. Kalachinskaya, Yu. V. Sheretov, I. A. Shirokov

The paper contains the original mathematical model that describes the incompressible electrically conducting fluid flows under the influence of the electromagnetic field - quasi-magneto-hydrodynamic (QMHD) equation system. Simplified inductionless approximation of QMHD system for the quasi-neutral liquid is constructed and implemented for numerical simulatio

Ilya A. Bogaevsky

In inviscid solutions of the forced Burgers equation the matter accumulates in the shock discontinuities. We describe the limit motion of particles everywhere including the shocks as the trajectories of a discontinuous velocity field being a generalization of the gradient of the limit potential. The latter is not differentiable but satisfies some convexity p

Dongsheng Liu

In this paper we give an asymptotic expansion including error terms for the number of cycles in homology classes for connected graphs. Mainly, we obtain formulae about the coefficients of error terms which depend on the homology classes and give two examples of how to calculate the coefficient of first error term.

Enrica Duchi, Gilles Schaeffer

In this paper we consider a model of particles jumping on a row of cells, called in physics the one dimensional totally asymmetric exclusion process (TASEP). More precisely we deal with the TASEP with open or periodic boundary conditions and with two or three types of particles. From the point of view of combinatorics a remarkable feature of this Markov chai

P. B. Kronheimer

Generalized Donaldson invariants of 4-manifolds are defined, using moduli spaces of anti-self-dual connections with structure group SU(N) or PSU(N). Some values of the invariants are calculated for the case that the 4-manifold arises by the knot-complement construction of Fintushel and Stern. The results are consistent with predictions of Marino and Moore.

Christopher Deninger, Annette Werner

For a certain class of vector bundles E on abelian varieties A over local fields containing all line bundles algebraically equivalent to zero we define a canonical representation of the Tate module of A on the fibre of E in the zero section. This extends an old construction of Tate for line bundles to vector bundles of higher rank. We also compare this const

D. Bulacu, S. Caenepeel, B. Torrecillas

For a quasi-Hopf algebra $H$, a left $H$-comodule algebra $\mf{B}$ and a right $H$-module coalgebra $C$ we will characterize the category of Doi-Hopf modules ${}^C{\cal M}(H)_{\mf{B}}$ in terms of modules. We will also show that for an $H$-bicomodule algebra $\mb{A}$ and an $H$-bimodule coalgebra $C$ the category of generalized Yetter-Drinfeld modules ${}_{\

Dalide Pontoni

We compute the Small Quantum Cohomology of Hilb^2(P^1xP^1) and determine recursively most of the Big Quantum Cohomology. We prove a relationship between the invariants so obtained and the enumerative geometry of hyperelliptic curves in P^1xP^1. This extends the results obtained by Graber for Hilb^2(P^2) and hyperelliptic curves in P^2.

Pietro Polesello, Ingo Waschkies

For a given category C and a topological space X, the constant stack on X with stalk C is the stack of locally constant sheaves with values in C. Its global objects are classified by their monodromy, a functor from the Poincare groupoid of X to C. In this paper we recall these notions from the point of view of higher category theory and then define the 2-mon

Ross Geoghegan, Pedro Ontaneda

This paper is about geometric and topological properties of a proper CAT(0) space $X$ which is cocompact - i.e. which has a compact generating domain with respect to the full isometry group. It is shown that geodesic segments in $X$ can &#34;almost&#34; be extended to geodesic rays. A basic ingredient of the proof of this geometric statement is the topologic

Pavel Etingof

In 1986 Goldman introduced a Lie algebra structure on the linear span L of conjugacy classes of the fundamental group of a closed oriented surface. It is easy to see that the class e_1 of the trivial loop is a central element in L. We prove that any central element of L is a multiple of e_1 (a conjecture communicated to the author by Chas and Sullivan), and

Stanislav Krugljak, Stanislav Popovych, Yurii Samoilenko

We study the connection between *-representations of algebras associated with graphs, locally-scalar graph representations and the problem about the spectrum of a sum of two Hermitian operators. For algebras associated with Dynkin graphs we give an explicit description of the parameters for which there are irreducible representations and an algorithm for con

Yonatan Bilu

Hofmman&#39;s bound on the chromatic number of a graph states that $χ\geq 1 - \frac {λ_1} {λ_n}$. Here we show that the same bound, or slight modifications of it, hold for several graph parameters related to the chromatic number: the vector coloring number, the $ψ$-covering number and the $λ$-clustering number.

Martin Goldstern

We give an example of a finitely based locally finite variety which has uncountably many term clones. (Such varieties were known before.)

Desmond Sheiham

We use the Blanchfield-Duval form to define complete invariants for the cobordism group C_{2q-1}(F_μ) of (2q-1)-dimensional μ-component boundary links (for q\geq2). The author solved the same problem in math.AT/0110249 via Seifert forms. Although Seifert forms are convenient in explicit computations, the Blanchfield-Duval form is more intrinsic and appears n

Martin Goldstern, Saharon Shelah

We give three examples of large intervals in the lattice of (local) clones on an infinite set X, by exhibiting clones C_1, C_2, C_3 such that: (1) the interval [C_1, O] in the lattice of local clones is (as a lattice) isomorphic to {0,1,2, ...} under the divisibility relation, (2) the interval [C_2, O] in the lattice of local clones is isomorphic to the cong

Michael Christ, James Colliander, Terence Tao

In a recent paper, Kenig, Ponce and Vega study the low regularity behavior of the focusing nonlinear Schrödinger (NLS), focusing modified Korteweg-de Vries (mKdV), and complex Korteweg-de Vries (KdV) equations. Using soliton and breather solutions, they demonstrate the lack of local well-posedness for these equations below their respective endpoint regularit

Leonard Susskind

I make a number of comments about Smolin&#39;s theory of Cosmic Natural Selection.

A. Fabbri, D. Langlois, D. A. Steer, R. Zegers

In the context of brane cosmology, a scenario where our universe is a 3+1-dimensional surface (the ``brane'') embedded in a five-dimensional spacetime (the ``bulk''), we study geometries for which the brane is anisotropic - more specifically Bianchi I - though still homogeneous. We first obtain explicit vacuum bulk solutions with anisotropic three-dimensiona

B. Eynard

We rewrite the loop equations of the hermitian matrix model, in a way which allows to compute all the correlation functions, to all orders in the topological $1/N^2$ expansion, as residues on an hyperelliptical curve. Those residues, can be represented diagrammaticaly as Feynmann graphs of a cubic interaction field theory on the curve.

S. Odake, R. Sasaki

An affine Toda-Sutherland system is a quasi-exactly solvable multi-particle dynamics based on an affine simple root system. It is a `cross&#39; between two well-known integrable multi-particle dynamics, an affine Toda molecule and a Sutherland system. Polynomials describing the equilibrium positions of affine Toda-Sutherland systems are determined for all af

E. Di Grezia, G. Mangano, G. Miele

We study symmetry of space-time in presence of a minimally coupled scalar field interacting with a Kalb--Ramond tensor fields in a homogeneous but initially anisotropic universe. The analysis is performed for the two relevant cases of a pure cosmological constant and a minimal quadratic, renormalizable, interaction term. In both cases, due to expansion, a co

Luis Gonzalez-Mestres

Assuming the existence of a local vacuum rest frame (LVRF), and using suitable algebraic tranformations, the internal structure of ultra-high energy particles (UHEPs) is studied in the presence of Lorentz symmetry violation (LSV) at the Planck scale. Violations of the standard Lorentz contraction and time dilation formulae are made explicit. Dynamics in the

Lee Smolin

It is explained in detail why the Anthropic Principle (AP) cannot yield any falsifiable predictions, and therefore cannot be a part of science. Cases which have been claimed as successful predictions from the AP are shown to be not that. Either they are uncontroversial applications of selection principles in one universe (as in Dicke&#39;s argument), or the

Subir Ghosh

Effects of noncommutativity are investigated in planar quantum mechanics in the coordinate representation. Generally these issues are addressed by converting to the momentum space. In the first part of the work we show noncommutative effects in a Gaussian wavepacket through the broadening of its width. We also rederive results on *-product of Gaussian wavepa

Don Colladay, Patrick McDonald

The theory of statistical mechanics is studied in the presence of Lorentz-violating background fields. The analysis is performed using the Standard-Model Extension (SME) together with a Jaynesian formulation of statistical inference. Conventional laws of thermodynamics are obtained in the presence of a perturbed hamiltonian that contains the Lorentz violatin

Dmitri Diakonov

The functional determinant is computed exactly for quantum oscillations about periodic instantons with non-trivial values of the Polyakov line at spatial infinity (or holonomy). Such instantons can be viewed as composed of the Bogomolnyi--Prasad--Sommerfeld (BPS) monopoles or dyons. We find the weight or the probability with which dyons occur in the pure Yan

Gordon L. Kane, Haibin Wang, Lian-Tao Wang, Ting T. Wang

Some rare decay processes are particularly sensitive to physics beyond the Standard Model (SM) because they have no SM tree contributions. We focus on one of these, $B_{d}\to ϕK_{s}$. Our study is in terms of the high scale effective theory, and high scale models for the underlying theory, while previous studies have been focusing on the low scale effective

S. Y. Choi, J. Kalinowski, Y. Liao, P. M. Zerwas

For large masses, the two heavy neutral Higgs bosons are nearly degenerate in many 2--Higgs doublet models, and particularly in supersymmetric models. In such a scenario the mixing between the states can be very large if the theory is CP-noninvariant. We analyze the formalism describing this configuration, and we point to some interesting experimental conseq