May 2003 arXiv papers — page 27

G. Sandell, M. Wright, J. R. Forster

We report the detection of a massive rotating disk around the high-mass Class 0 candidate NGC 7538S. The disk is well-resolved with BIMA (HPBW =3.7") in 3.4 mm continuum and in H13CN J = 1 - 0. It is seen nearly edge on and has a size of ~ 30,000 AU. A young, powerful outflow perpendicular to the rotating disk is mapped in SiO J = 2 - 1 and HCO+ J = 1 -

S. R. Cranmer, A. A. van Ballegooijen

We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the idea that ions are energized by the dissipation of ion cyclotron resonant waves, but such high-frequency (i.e., small wavel

L. K. Townsley, E. D. Feigelson, T. Montmerle, P. S. Broos

We present the first high-spatial-resolution X-ray images of two high-mass star forming regions, the Omega Nebula (M 17) and the Rosette Nebula (NGC 2237--2246), obtained with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer (ACIS) instrument. The massive clusters powering these H II regions are resolved at the arcsecond level into >900 (M 17)

K. Mukai, M. Still, F. A. Ringwald

DQ Herculis (Nova Herculis 1934) is a deeply eclipsing cataclysmic variable containing a magnetic white dwarf primary. The accretion disk is thought to block our line of sight to the white dwarf at all orbital phases due to its extreme inclination angle. Nevertheless, soft X-rays were detected from DQ Her with ROSAT PSPC. To probe the origin of these soft X-

D. Boyanovsky, H. J. de Vega, M. Simionato

We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a phase transition at a critical temperature much larger than the electroweak scale. The dynamics after the transition fea

G. Lamer, P. Uttley, I. M. McHardy

We have monitored the Seyfert galaxy NGC 3227 with the Rossi X-ray Timing Explorer (RXTE) since January 1999. During late 2000 and early 2001 we observed an unusual hardening of the 2-10 keV X-ray spectrum which lasted several months. The spectral hardening was not accompanied by any correlated variation in flux above 8 keV. We therefore interpret the spectr

O. Shemmer, P. Uttley, H. Netzer, I. M. McHardy

This paper presents the results of a dense and intensive X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051 carried out in 2000. Results of the optical analysis are consistent with previous measurements. The amplitude of optical emission line variability is a factor of two larger than that of the underlying optical continuum, but part

H. Maness, S. D. Vrtilek

An early analysis of Chandra observations of the planetary nebula NGC 6543 suggested that the location and the derived temperature for the X-ray emitting region is inconsistent with the abundances measured for this object (Chu et al. 2001). We revisit observations of this source (following significant updates to both the reprocessing and extraction software)

Neal J. Evans

Crucial steps in the formation of stars and planets can be studied only at mid-infrared to far-infrared wavelengths, where SIRTF provides an unprecedented improvement in sensitivity. We will use all three SIRTF instruments (IRAC, MIPS, and IRS) to observe sources that span the evolutionary sequence from molecular cores to protoplanetary disks, encompassing a

S. S. Gershtein, A. A. Logunov, M. A. Mestvirishvili, N. P. Tkachenko

It is shown that using the relativistic field theory of gravity (RTG) and measured value of $Ω_{tot}$ one can obtain the upper limit on the graviton mass with 95%C.L.: $m\leq 1.6\cdot 10^{-66}$ [g]; within the $(1σ)$ range its probable value is $m_{g}= 1.3\cdot 10^{-66}$ [g]. It is pointed out that according to RTG the presence of the quintessence is necessa

Neeraj Gupta, Raghunathan Srianand, Patrick Petitjean, Cedric Ledoux

We present the analysis of two BALs seen in the spectrum of the QSO SDSS J160501.21-011220.0. Our UVES spectrum shows two well detached BALs at z(abs)= 4.685 and 4.855. The system at z(abs)= 4.855 covers the background source completely suggesting that the gas is located outside the BLR. On the contrary the system at z(abs)= 4.685 has a covering factor of ~0

Charles H. Lineweaver, Tamara M. Davis

In a previous paper we addressed the question "Does the Rapid Appearance of Life on Earth Suggest that Life is Common in the Universe?" The non-observability of recent biogenesis is a self-selection effect that needs to be considered if inferences are to be drawn from the rapidity of terrestrial biogenesis. We discuss several approaches that have bee

Andrei M. Beloborodov

The customary picture of the fireball deceleration by an external medium neglects two physical agents in the problem that are important at radii R<10^{17} cm: a radiative precursor (the prompt GRB) and a relativistic front of free neutrons. The radiative precursor preaccelerates the medium and loads it with e+- pairs. This provides a new explanation for the

Tim de Zeeuw

In the past decade, much effort was devoted to measure the masses of supermassive black holes in galactic nuclei, to establish the relation between black hole mass and the global/nuclear properties of the host galaxy, and to understand the role of these objects in the formation and subsequent dynamical evolution of galaxies. This whole area of research is an

E. De Donder, D. Vanbeveren

A population number synthesis code follows in detail the evolution of a population of single stars and of close binaries. We use our code to simulate the population of neutron star - neutron star and black hole - neutron star binaries. We then combine our population number synthesis code with a galactic chemical evolutionary model in order to follow the time

Scott Pratt, Silvio Petriconi

Two-Particle correlations based on the interference of identical particles has provided the chief means for determining the shape and lifetime of sources in relativistic heavy ion collisions. Here, Strong and Coulomb induced correlations are shown to provide equivalent information.

Thomas. G. Rizzo

We explore the capabilities of the LHC and the Linear Collider(LC) to distinguish the production of Kaluza-Klein(KK) excitations from an ordinary $Z&#39;$ within the context of theories with TeV scale extra dimensions. At the LHC, these states are directly produced in the Drell-Yan channel while at the LC the effects of their exchanges are indirectly felt as

Gaetano Bertoldi

We construct an N=1 theory with gauge group U(nN) and degree n+1 tree level superpotential whose matrix model spectral curve develops an A_{n+1} Argyres-Douglas singularity. We evaluate the coupling constants of the low-energy U(1)^n theory and show that the large N expansion is singular at the Argyres-Douglas points. Nevertheless, it is possible to define a

P. Meszaros, M. J. Rees

We discuss the X-ray flux of gamma-ray burst afterglows at redshifts in the range 3-30, including the effects of the intergalactic He II absorption. We point out that strong X-ray lines may form locally in burst afterglows starting minutes after the trigger. This can provide distinctive X-ray distance indicators out to the redshifts where the first generatio

Scott Dodelson, Lam Hui

We demonstrate that the gravity wave background amplitude implies a robust upper bound on the ratio: λ/ H^{-1} < e^60, where λis the proper wavelength of fluctuations of interest and H^{-1} is the horizon at the end of inflation. The bound holds as long as the energy density of the universe does not drop faster than radiation subsequent to inflation. This li

Ken Intriligator, Brian Wecht

We consider general aspects of the realization of R and non-R flavor symmetries in the AdS_5 x H_5 dual of 4d N=1 superconformal field theories. We find a general prescription for computing the charges under these symmetries for baryonic operators, which uses only topological information (intersection numbers) on H_5. We find and discuss a new correspondence

Stephen D. H. Hsu

The nonlinear oscillations of a scalar field are shown to have cosmological equations of state with $w = p / ρ$ ranging from $-1 < w < 1$. We investigate the possibility that the dark energy is due to such oscillations.

J. P. Kneller, G. C. McLaughlin

Big Bang Nucleosynthesis (BBN) has increasingly become the tool of choice for investigating the permitted variation of fundamental constants during the earliest epochs of the Universe. Here we present a BBN calculation that has been modified to permit changes in the QCD scale, Lambda_QCD. The primary effects of changing the QCD scale upon BBN are through the

Christopher P. Herzog, James McKernan

The AdS/CFT correspondence relates dibaryons in superconformal gauge theories to holomorphic curves in Kaehler-Einstein surfaces. The degree of the holomorphic curves is proportional to the gauge theory conformal dimension of the dibaryons. Moreover, the number of holomorphic curves should match, in an appropriately defined sense, the number of dibaryons. Us

Martin B. Einhorn, Finn Larsen

We discuss the treatment of squeezed states as excitations in the Euclidean vacuum of de Sitter space. A comparison with the treatment of these states as candidate no-particle states, or alpha-vacua, shows important differences already in the free theory. At the interacting level alpha-vacua are inconsistent, but squeezed state excitations seem perfectly acc

Satoshi Mishima, A. I. Sanda

New physics contributions to B decays often arise through chromo-magnetic penguin operators. To look for new physics effects in B decays, it is useful to be able to estimate the hadronic matrix elements for the chromo-magnetic operator. We compute this contribution to B ->phi K decays using PQCD methods. It is shown that, if the Wilson coefficient of the new

Artie P. Hatzes, William D. Cochran, Michael Endl, Barbara McArthur

We report on the detection of a planetary companion in orbit around the primary star of the binary system $γ$ Cephei. High precision radial velocity measurements using 4 independent data sets spanning the time interval 1981--2002 reveal long-lived residual radial velocity variations superimposed on the binary orbit that are coherent in phase and amplitude wi

D. J. H. Chung, A. Notari, A. Riotto

During inflation, primordial energy density fluctuations are created from approximate de Sitter vacuum quantum fluctuations redshifted out of the horizon after which they are frozen as perturbations in the background curvature. In this paper we demonstrate that there exists an intrinsic theoretical uncertainty in the inflationary predictions for the curvatur

K. -I. Nishikawa, P. Hardee, G. Richardson, R. Preece

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP)

Alex Buchel, Johannes Walcher

This is a note on the coupled supergravity-tachyon matter system, which has been earlier proposed as a candidate for the effective space-time description of S-branes. In particular, we study an ansatz with the maximal ISO(p+1)xSO(8-p,1) symmetry, for general brane dimensionality p and homogeneous brane distribution in transverse space ρ_\perp. A simple appli

Scott F. Anderson, Wolfgang Voges, Bruce Margon, Joachim Trümper

Many open questions in X-ray astronomy are limited by the relatively small number of objects in uniform optically-identified samples, especially when rare subclasses are considered, or subsets isolated to search for evolution or correlations between wavebands. We describe initial results of a program aimed to ultimately yield 10^4 X-ray source identification

Jens O Andersen

We review recent advances in the theory of the three-dimensional dilute homogeneous Bose gas at zero and finite temperature. Effective field theory methods are used to formulate a systematic perturbative framework that can be used to calculate the properties of the system at T=0. The perturbative expansion of these properties is essentially an expansion in t

Roberto Artuso, Predrag Cvitanovic, Gregor Tanner

In a generic dynamical system chaos and regular motion coexist side by side, in different parts of the phase space. The border between these, where trajectories are neither unstable nor stable but of marginal stability, manifests itself through intermittency, dynamics where long periods of nearly regular motions are interrupted by irregular chaotic bursts. W

Peter W. Shor

We reduce the number of open additivity problems in quantum information theory by showing that four of them are equivalent. We show that the conjectures of additivity of the minimum output entropy of a quantum channel, additivity of the Holevo expression for the classical capacity of a quantum channel, additivity of the entanglement of formation, and strong

Shin Nakamura

We consider closed-string tachyon condensation in the twisted sectors on the C/Z_{2n+1} \times R^{7,1} orbifold. We calculate the localized energy density in the fixed plane on the orbifold at the one-loop level, and we obtain the decay rate per unit volume of the fixed plane to leading order. We show that the decay rate increases monotonically as a function

Magnus Jacobson, Tommy Ohlsson

We investigate matter-induced (or extrinsic) CPT violation effects in neutrino oscillations in matter. Especially, we present approximate analytical formulas for the CPT-violating probability differences for three flavor neutrino oscillations in matter with an arbitrary matter density profile. Note that we assume that the CPT invariance theorem holds, which

D. Kruse, C. von Cube, C. Zimmermann, Ph. W. Courteille

We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-$Q$ optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical molasses an additional friction force is applied to the atoms. We observe the displacement of the atoms accelerated by mom

R. M. Godbole, A. De Roeck, A. Grau, G. Pancheri

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear $e^+e^-$ collider. We extend, to higher energy, our previous estimates of the accuracy with which the \gamgam\ cross-section needs to be measured, in order to distinguish between

J. L. González, E. V. L. de Mello

Recently experiments on high critical temperature superconductors has shown that the doping levels and the superconducting gap are usually not uniform properties but strongly dependent on their positions inside a given sample. Local superconducting regions develop at the pseudogap temperature ($T^*$) and upon cooling, grow continuously. As one of the consequ

Gyorgy Szabo, Attila Szolnoki, Rudolf Izsak

The spatial rock-scissors-paper game (or cyclic Lotka-Volterra system) is extended to study how the spatiotemporal patterns are affected by the constructed backgrounds providing uniform number of neighbors (degree) at each site. On the square lattice this system exhibits a self-organizing pattern with equal concentration of the competing strategies (species)

Massimo Bianchi, Jose F. Morales, Henning Samtleben

We derive the spectrum of Kaluza-Klein descendants of string excitations on AdS_5 x S^5. String states are organized in long multiplets of the AdS supergroup SU(2,2|4,R) with a rich pattern of shortenings at the higher spin enhancement point λ=0. The string states holographically dual to the higher spin currents of SYM theory in the strict zero coupling limi

Tohru Eguchi, Yuji Sugawara

We study the N=1 version of Argyres-Douglas (AD) points by making use of the recent developments in understanding the dynamics of the chiral sector of N=1 gauge theories. We shall consider N=1 U(N) gauge theories with an adjoint matter and look for the tree-level superpotential W(x) which reproduces the N=2 AD points via the factorization equation relating t

M. Biyajima, T. Mizoguchi, N. Suzuki

In order to analyze data on charged pions correlation channels, pi^+(2pi^-) and pi^-(2pi^+), we propose new interferometry approach using the Coulomb wave function. We show that to describe adequately data we have to introduce new parameter describing the contribution of pi^-(k_1) pi^+(k_2) --> pi^-(k_2) pi^+(k_1) process. Using this new formula we analyze d

V. V. Braguta, A. A. Likhoded, A. E. Chalov

The dependence of the T-odd correlation on the effective Lagrangian parameters in the $K^+ \to πl νγ, l=e, μ$ decays is analyzed. It is shown that the introduced observable is perspective in a search for new physics in the vector and pseudovector sector of the Lagrangian. As for scalar and pseudoscalar sectors, the T-odd correlation studies will not allow on

Mun Dae Kim, Jongbae Hong

We propose a coupling scheme for the three-Josephson junction qubits which uses a connecting loop, but not mutual inductance. Present scheme offers the advantages of a large and tunable level splitting in implementing the controlled-NOT (CNOT) operation. We calculate the switching probabilities of the coupled qubits in the CNOT operations and demonstrate tha

Tadakatsu Sakai, Jacob Sonnenschein

We incorporate massive flavored fundamental quarks in the supergravity dual of N=1 SYM by introducing D7 brane probes to the Klebanov Strassler background. We find probe configurations that solve the D7 equations of motion. We compute the quadratic fluctuations of the D7 brane and extract the spectrum of vector and pseudo scalar flavored mesons. The spectra

Shoichi Sasaki

The present status of the Roper resonance in lattice QCD is reviewed. Some of the latest lattice results are discussed with particular emphasis on a large systematic error stemming from the finite size effect. These results suggest that the Roper resonance can be described by the simple three quark excitation of sizable extent.

Andrew A. Rawlinson

We introduce a transformation for converting a series in a parameter, λ, to a series in the inverse of the parameter λ^{-1}. By applying the transform on simple examples, it becomes apparent that there exist relations between convergent and divergent series, and also between large- and small-coupling expansions. The method is also applied to the divergent se

Karl Hess, Walter Philipp

Mermin states that his nontechnical version of Bell&#39;s theorem stands and is not invalidated by time and setting dependent instrument parameters as claimed in one of our previous papers. We identify deviations from well-established protocol in probability theory as well as mathematical contradictions in Mermin&#39;s argument and show that Mermin&#39;s con

D. V. Kupriyanov, I. M. Sokolov, N. V. Larionov, P. Kulatunga

We report a combined theoretical and experimental study of the spectral and polarization dependence of near resonant radiation coherently backscattered from an ultracold gas of 85Rb atoms. Measurements in an approximately 6 MHz range about the 5s^{2}S_{1/2}- 5p^{2}P_{3/2}, F=3 - F&#39;=4 hyperfine transition are compared with simulations based on a realistic

A. Wojcik, A. Grudka, R. W. Chhajlany

The notion of equivalence of maximally entangled bases of bipartite d-dimensional Hilbert spaces is introduced. An explicit method of inequivalent bases construction is presented.

Andris Ambainis, Yaoyun Shi

Quantum fingerprints are useful quantum encodings introduced by Buhrman, Cleve, Watrous, and de Wolf (Physical Review Letters, Volume 87, Number 16, Article 167902, 2001; quant-ph/0102001) in obtaining an efficient quantum communication protocol. We design a protocol for constructing the fingerprint in a distributed scenario. As an application, this protocol

Sisir Roy, Menas Kafatos

The recent controversy of applicability of quantum formalism to brain dynamics has been critically analysed. The prerequisites for any type of quantum formalism or quantum field theory is to investigate whether the anatomical structure of brain permits any kind of smooth geometric notion like Hilbert structure or four dimensional Minkowskian structure for qu

Subhash Kak

Associating a physical process with the pure entangled state 1/sqrt 2 (|00> + |11>) is an idealization unless the pair is so prepared using an appropriate quantum gate operating on a known state. Questions related to the reference frame for measurement of the entangled state are considered. Some applications are described.

M. Yudin

The principles of behavior of the system with discrete interactions are applied to description of motion of the relativistic particle. Applying the concept of non-local behavior both to position in space and to time, the apparently covariant equation of motion of the particle (Klein-Gordon) is defined. Based on the assumption that the form of the equation ha

J. K. Black, A. N. Brunton, N. P. Bannister, P. Deines-Jones

Lobster-ISS is a revolutionary astrophysical X-ray all-sky monitor scheduled for deployment as an attached payload on the International Space Station (ISS) in 2009. Using a new wide field-of-view focusing optic, Lobster-ISS provides an order-of-magnitude improvement in the sensitivity of all-sky monitors in the soft X-ray band (0.1-3.0 keV). This lobster-eye

R. C. Gupta

Mass is in the central theme everywhere from atom to galaxy. But what is mass ? Is it scalar or vector ? Apparently it appears that mass is scalar; but relativistic mass is velocity dependent and moving mass such as photon is vector boson. In the present paper a new concept is introduced that in general, mass is neither scalar nor vector rather, mass is a qu

V. Venturi, P. J. Leo, E. Tiesinga, C. J. Williams

We predict the presence and positions of purely-long-range bound states of $^4$He$(2s ^3S)+{}^4$He$(2p ^3P)$ near the $2s ^3S_1+2p ^3P_{0,1}$ atomic limits. The results of the full multichannel and approximate models are compared, and we assess the sensitivity of the bound states to atomic parameters characterizing the potentials. Photoassociation to these p

Alan McKane, David Alonso, Ricard Sole

Recent theoretical approaches to community structure and dynamics reveal that many large-scale features of community structure (such as species-rank distributions and species-area relations) can be explained by a so-called neutral model. Using this approach, species are taken to be equivalent and trophic relations are not taken into account explicitly. Here

M. Swisdak, B. N. Rogers, J. F. Drake, M. A. Shay

We present particle-in-cell simulations of collisionless magnetic reconnection in a system (like the magnetopause) with a large density asymmetry across the current layer. In the presence of an ambient component of the magnetic field perpendicular to the reconnection plane the gradient creates a diamagnetic drift that advects the X-line with the electron dia

J. B. Almeida, V. Lakshminarayanan

By combining the definition of the Wigner distribution function (WDF) and the matrix method of optical system modeling, we can evaluate the transformation of the former in centered systems with great complexity. The effect of stops and lens diameter are also considered and are shown to be responsible for non-linear clipping of the resulting WDF in the case o

S. Aroua, L. Zamick, Y. Y. Sharon, E. Moya de Guerra

We study the response of isovector orbital magnetic dipole (IOMD) transitions to the quadrupole-quadrupole ($Q \cdot Q$) interaction, to the isospin-conserving pairing interaction (ICP) and to combinations of both. We find qualitatively different behaviours for transitions in which the final isospin differs from the initial isospin versus cases where the two

K. Shekhter, C. Fuchs, Amand Faessler, M. Krivoruchenko

We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($ρ,ω$) is described via the excitation of nuclear resonances ($R$). The theoretical framework is an extended vector meson dominance model (eVMD). The treatment of the resonance decays $R\longmapsto NV$ with a

Nikola Buric, Dragana Todorovic

Small lattices of $N$ nearest neighbor coupled excitable FitzHugh-Nagumo systems, with time-delayed coupling are studied, and compared with systems of FitzHugh-Nagumo oscillators with the same delayed coupling. Bifurcations of equilibria in N=2 case are studied analytically, and it is then numerically confirmed that the same bifurcations are relevant for the

C. Morosi, G. Tondo

Starting from the tri-Hamiltonian formulation of the Lagrange top in a six-dimensional phase space, we discuss the reduction of the vector field and of the Poisson tensors. We show explicitly that, after the reduction on each one of the symplectic leaves, the vector field of the Lagrange top is separable in the sense of Hamilton-Jacobi.

W. Chen

The dissipation of acoustic wave propagation has long been found to obey an empirical power function of frequency, whose exponent parameter varies through different media. This note aims to unveil the inherent relationship between this dissipative frequency power law and 1/f spectral trend. Accordingly, the 1/f spectral trend can physically be interpreted vi

Adrian Constantin, Boris Kolev

We show that certain right-invariant metrics endow the infinite-dimensional Lie group of all smooth orientation-preserving diffeomorphisms of the circle with a Riemannian structure. The study of the Riemannian exponential map allows us to prove infinite-dimensional counterparts of results from classical Riemannian geometry: the Riemannian exponential map is

J. Fernández Núñez, W. García Fuertes, A. M. Perelomov

We express the Hamiltonian of the quantum trigonometric Calogero-Sutherland model related to the Lie algebra $D_4$ in terms of a set of Weyl-invariant variables, namely, the characters of the fundamental representations of the Lie algebra. This parametrization allows us to solve for the energy eigenfunctions of the theory and to study properties of the syste

D. R. Heath-Brown

All the results in this paper are conditional on the Riemann Hypothesis for the L-functions of elliptic curves. Under this assumption, we show that the average analytic rank of all elliptic curves over Q is at most 2, thereby improving a result of Brumer. We also show that the average within any family of quadratic twists is at most 3/2, improving a result o

Harm Derksen

The denominator of the Hilbert series of a finitely generated R-module M does not always divide the denominator of the Hilbert series of R. For this reason, we define the universal denominator. The universal denominator of a module M is the least common multiple of the denominators of the Hilbert series of all submodules of M. The universal denominator behav

Alexei Yu. Karlovich

We prove that the set of all integrable functions whose sequences of negative (resp. nonnegative) Fourier coefficients belong to $\ell^1\cap\ell^Φ_{ϕ,w}$ (resp. to $\ell^1\cap\ell^Ψ_{ψ,\varrho}$), where $\ell^Φ_{ϕ,w}$ and $\ell^Ψ_{ψ,\varrho}$ are two-weighted Orlicz sequence spaces, forms an algebra under pointwise multiplication whenever the weight sequence

Alexei Yu. Karlovich

We prove necessary conditions for Fredholmness of singular integral operators with piecewise continuous coefficients on weighted Banach function spaces. These conditions are formulated in terms of indices of submultiplicative functions associated with local properties of the space, of the curve, and of the weight. As an example, we consider weighted Nakano s

Barbara Schapira

In this work, we prove the so-called &#34;Shadow lemma&#34; on geometrically finite manifolds of variable negative curvature. We deduce a result of non divergence of the horospheres of such manifolds.

A. Buonocore, G. Esposito, V. Giorno, C. Valerio

A mathematical description of the refractoriness period in neuronal diffusion modeling is given and its moments are explicitly obtained in a form that is suitable for quantitative evaluations. Then, for the Wiener, Ornstein-Uhlenbeck and Feller neuronal models, an analysis of the features exhibited by the mean and variance of the first passage time and of re

A. V. Lebedev

In this paper we investigate the interrelation between the topological freedom of partial actions of discrete groups and faithful representations of partial crossed products.

Nenad Ujevic

An optimal 3-point quadrature formula of closed type is derived. Various error inequalities are established. Applications in numerical integration are also given.

A. Chakrabarti

Braid matrices $\hat{R}(θ)$, corresponding to vector representations, are spectrally decomposed obtaining a ratio $f_{i}(θ)/f_{i}(-θ)$ for the coefficient of each projector $P_{i}$ appearing in the decomposition. This directly yields a factorization $(F(-θ))^{-1}F(θ)$ for the braid matrix, implying also the relation $\hat{R}(-θ)\hat{R}(θ)=I$.This is achieved

Adrian Andrada, Simon Salamon

A study is made of real Lie algebras admitting compatible complex and product structures, including numerous 4-dimensional examples. If g is a Lie algebra with such a structure then its complexification has a hypercomplex structure. It is shown in addition that g splits into the sum of two left-symmetric subalgebras. Interpretations of these results are obta

JeongHyeong Park

Let (M,g) be a compact Einstein manifold with smooth boundary. We consider the spectrum of the p form valued Laplacian with respect to a suitable boundary condition. We show that certain geometric properties of the boundary may be spectrally characterized in terms of this data where we fix the Einstein constant.

Siu-Hung Ng

Let $H$ be a non-semisimple Hopf algebra with antipode $S$ of dimension $pq$ over an algebraically closed field of characteristic 0 where $p \le q$ are odd primes. We prove that $\Tr(S^{2p})=p^2d$ where $d \equiv pq \pmod{4}$. As a consequence, if $p,q$ are twin primes, then any Hopf algebra of dimension $pq$ is semisimple.

Albert Fannjiang, Lech Wolowski

We consider dissipative systems resulting from the Gaussian and $alpha$-stable noise perturbations of measure-preserving maps on the $d$ dimensional torus. We study the dissipation time scale and its physical implications as the noise level $\vep$ vanishes. We show that nonergodic maps give rise to an $O(1/\vep)$ dissipation time whereas ergodic toral automo

Eduardo J. Dubuc

We elaborate on the representation theorems of topoi as topoi of discrete actions of various kinds of localic groups and groupoids. We introduce the concept of &#34;proessential point&#34; and use it to give a new characterization of pointed Galois topoi. We establish a hierarchy of connected topoi: [1. essentially pointed Atomic = locally simply connected],

Gabor Lukacs

For two not necessarily commutative topological groups G and T, let H(G,T) denote the space of all continuous homomorphisms from G to T with the compact-open topology. We prove that if G is metrizable and T is compact then H(G,T) is a k-space. As a consequence we obtain that if G_1 is a dense subgroup of G then H(G_1,T) is homeomorphic to H(G,T), and if G is

Daniel Grunberg

We prove the integrality of the open instanton numbers in two examples of counting holomorphic disks on local Calabi-Yau threefolds: the resolved conifold and the degenerate $ ¶\times ¶$. Given the B-model superpotential, we extract by hand all Gromow-Witten invariants in the expansion of the A-model superpotential. The proof of their integrality relies on e

Daniele Perini

Building a consistent Quantum Theory of Gravity is one of the most challenging aspects of modern theoretical physics. In the past couple of years, new attempts have been made along the path of ``asymptotic safety&#39;&#39; through the use of Exact Renormalisation Group Equations, which hinge on the existence of a non-trivial fixed point of the flow equations

Dmitriy V. Uvarov

Lagrangian and Hamiltonian dynamics of de Azcarraga-Lukierski N=2 massive superparticle is considered in the framework of twistor-like Lorentz-harmonic approach. The emphasis is on the study of the interaction with external Abelian gauge superfield. The requirement of preservation of all gauge symmetries of the free model including kappa-symmetry yields corr

Eric Nicholson

We study the perturbative approach to the Wilsonian integration of noncommutative gauge theories in the matrix representation. We begin by motivating the study of noncommutative gauge theories and reviewing the matrix formulation. We then systematically develop the perturbative treatment of UV states and calculate both the leading and next to leading order o

Chris Hull

Supersymmetric solutions of 11-dimensional supergravity can be classified according to the holonomy of the supercovariant derivative arising in the Killing spinor condition. It is shown that the holonomy must be contained in $\SL(32,\R)$. The holonomies of solutions with flux are discussed and examples are analysed. In extending to M-theory, account has to b

P. Desrosiers, L. Lapointe, P. Mathieu

We first review the construction of the supersymmetric extension of the (quantum) Calogero-Moser-Sutherland (CMS) models. We stress the remarkable fact that this extension is completely captured by the insertion of a fermionic exchange operator in the Hamiltonian: sCMS models ({\it s} for supersymmetric) are nothing but special exchange-type CMS models. Unde

Michael J. W. Hall, Kailash Kumar, Marcel Reginatto

(A) The momentum density conjugate to a bosonic quantum field splits naturally into the sum of a classical component and a nonclassical component. It is shown that the field and the nonclassical component of the momentum density satisfy an_exact_ uncertainty relation, i.e., an equality, which underlies the Heisenberg-type uncertainty relation for fields. (B)

Ulrich D. Jentschura

Quantum electrodynamic (QED) effects that shift the binding energies of hydrogenic energy levels have been expressed in terms of a semi-analytic expansion in powers of Zalpha and ln[(Zalpha)^{-2}], where Z is the nuclear charge number and alpha is the fine-structure constant. For many QED effects, numerical data are available in the domain of high Z where th

Claude Bourrely, Jacques Soffer

A statistical model for the parton distributions in the nucleon has proven its efficiency in the analysis of deep inelastic scattering data, so we propose to extend this approach to the description of unpolarized fragmentation functions for the octet baryons. The characteristics of the model are determined by using some data on the inclusive production of pr

Roberto Casalbuoni, Giuseppe Nardulli

Inhomogeneous superconductivity arises when the species participating in the pairing phenomenon have different Fermi surfaces with a large enough separation. In these conditions it could be more favorable for each of the pairing fermions to stay close to its Fermi surface and, differently from the usual BCS state, for the Cooper pair to have a non zero total

Ulrich D. Jentschura

We study a specific correction to the Bethe logarithm induced by potentials which are proportional to a Dirac-delta function in coordinate space (&#34;local potentials&#34;). Corrections of this type occur naturally in the calculation of various self-energy corrections to the energy of bound states. Examples include logarithmic higher-order binding correctio

Ulrich D. Jentschura

Analytic calculations of the Lamb shift represent a considerable challenge due to the size and the complexity of the expressions that occur in intermediate steps. In the current work, we present a method for the treatment of the bound-state self-energy in higher orders. Advantage is taken of computer algebra systems. The method is applied to the 2P-states, a

Francesca Borzumati, Christoph Greub, Youichi Yamada

The charged-Higgs contributions to the decay \bar{B} -> X_s gamma are discussed in the minimal supersymmetric standard model at large tan beta. These contributions receive two-loop O(alpha_s tan beta) corrections by squark-gluino subloops, which are nondecoupling in the limit of heavy superpartners and possibly large. Their leading parts are already known an

C. D. Lu

The rare decays $B^+ \to D_s^{+} ϕ$, $B^0 \to D_s^{(*)-} K^+$ and $B^+ \to D_s^{(*)+} \bar{K}^0$ can occur only via annihilation type diagrams in the standard model. We calculate these decays in perturbative QCD approach. We found that the calculated branching ratio of $B^0 \to D_s^- K^+$ agree with the data which had been observed in the KEK and SLAC B fact

C. R. Allton, S. Ejiri, S. J. Hands, O. Kaczmarek

We present results of a simulation of QCD on a 4x16^3 lattice with 2 continuum flavors of p4-improved staggered fermion with mass m/T=0.4. Derivatives of the thermodynamic grand potential with respect to quark chemical potential mu_q up to fourth order are calculated, enabling estimates of the pressure, quark number density and associated susceptibilities as

W. Bietenholz, P. Sodano

The concept of lattice modified symmetry formulations is adapted to the parity symmetry of gauge fields and applied to the pure Abelian Chern-Simons action in three dimensions. We derive an analogue of the Ginsparg-Wilson relation for the parity anti-symmetry, which is motivated from the perfect lattice action, and which we denote as the Chern-Simons-Ginspar

V. Azcoiti, G. Di Carlo, A. Galante, V. Laliena

Inspired by the results of the Ising model within an imaginary external magnetic field, we introduce a transformation in quantum systems with a theta-vacuum term that amounts to a rescaling of z=cos(theta/2). Making use of this transformation we are able to determine the order parameter as a function of theta. The approach is successfully tested in models wi