July 2001 arXiv papers — page 2

M. Coleman Miller, Eve C. Ostriker

As increasingly precise information about the spectrum of the cosmic microwave background fluctuations is gathered with balloon and satellite experiments, interest has grown in foreground sources of opacity affecting these observations. One potentially important source is electron scattering produced by a post-recombination luminosity source, which would sig

Rudy Wijnands

I will briefly discuss the implications of the recent quiescent Chandra observation of the long-duration neutron star transient KS 1731-260 (Wijnands et al. 2001a) on models for quiescent systems other than the Brown et al. (1998) cooling neutron star model. However, the Chandra results are not very constraining; for those models to be consistent with the da

W. D. Watson, H. W. Wyld

The relationship between the magnetic field and the circular polarization of astrophysical maser radiation due to the Zeeman effect under idealized conditions is investigated when the Zeeman splitting is much smaller than the spectral linebreadth and when radiative saturation is significant. The description of the circular polarization, as well as inferences

S. L. Lumsden, P. J. Puxley, M. G. Hoare

This paper continues our study of the behaviour of near infrared helium recombination lines in planetary nebula. We find that the 1.7007um 4^3D-3^3P HeI line is a good measure of the HeI recombination rate, since it varies smoothly with the effective temperature of the central star. We were unable to reproduce the observed data using detailed photoionisation

V. V. Bugaev, A. V. Plyasheshnikov, V. V. Vassiliev, T. C. Weekes

The sensitivity of ground-based imaging atmospheric Cherenkov gamma-ray observatories depends critically on the primary particle identification methods which are used to retain photon-initiated events and suppress the spurious background produced by cosmic rays. We suggest a new discrimination technique which utilizes differences in the fluctuations of the l

Matthew L. Lister

We present results from the highest resolution polarization imaging survey of a complete sample of extragalactic radio sources carried out to date. Our sample consists of a statistically complete flat-spectrum subset of 32 AGNs from the Pearson-Readhead survey, which has been studied at a variety of wavelengths and resolutions, including space-VLBI. Our obse

Alan P. Smale

In 2000 September we observed a bright X-ray burst from X2127+119 with the Rossi X-ray Timing Explorer. This burst has a multi-peaked profile, a peak luminosity of ~6.5x10^{38} erg s^{-1}, a total integrated energy of ~2x10^{40} ergs, and significant photospheric radius expansion to a maximum extent of R=118+-5 km. From the luminosity-temperature relation du

A. V. Plyasheshnikov, F. A. Aharonian

The technique of adjoint cascade equations has been applied to calculate the properties of extremely high energy gamma-rays in the energy range 10^18--10^22 eV with taking into account the LPM effect and interactions of gamma-rays with the geomagnetic field. Such characteristics are analysed as the electron and muon contents at the observation level, the ele

S. Aalto, G. Rydbeck

High resolution OVRO CO 1-0 observations of the inner kpc of the M51-companion NGC 5195 reveal the presence of a kpc-sized bar, or possibly an inclined disk with a two armed spiral, at the center of the optical bar. The molecular mass of the feature is 2.7 x 10^8 M_o, half of which is within a radius of 250 pc. The resulting gas surface density of 10^3 M_o p

F. De Paolis, G. Ingrosso, D. Orlando, L. Perrone

Gamma-Ray Bursts (GRBs) are expected to efficiently accelerate protons up to relativistic energies. High-energy photons can originate from decay of neutral pions produced by the interaction of these protons with the medium surrounding the source. In the same hadronic chain, high energy neutrinos are expected to be produced from decay of charged pions, as wel

P. Laurent, O. Limousin, G. Malaguti, E. Caroli

The main objective of the IBIS modeling activities is the generation of the IBIS spectral response matrix. This generation will be done step by step by firstly constructing "calibrated model" of each IBIS sub-systems. A "calibrated model" is defined as a GEANT Monte-Carlo model, further checked by intensive corresponding calibration. These ca

Giorgio Matt

The properties of Compton-thick AGN are reviewed, with particular emphasis on BeppoSAX hard X-ray observations. I also discuss evidence for the presence of Compton-thick, circumnuclear matter in unobscured AGN, and I briefly introduce the HELLAS2XMM 5-10 keV survey, discussed in more details in other contributions to this volume.

A. Bianchini, C. Tappert, H. Osborne, Ronald Canterna

From photometric observations of the old nova RW UMi (1956) we have discovered the presence of five sub-orbital periodicities. The longest period, P1 = 54.4 min, always observed, could be the beat period between the orbital period and the white dwarf (WD) spin period that we assume to be P2 = 33.4 min. The other suborbital periods could be orbital sidebands

P. Laurent, P. Goldoni, A. Goldwurm, F. Lebrun

The Imager on Board the Integral Satellite (IBIS) is one of the two main telescopes of Integral, the ESA soft gamma-ray mission to be launched in 2002. The Integral Core Program will be divided into two main parts, the Galactic Centre Deep Exposure program and the Galactic Plane Scan for a total amount of around 6 .6 10^6 seconds each year. In this paper, we

D. Tsiklauri, T. D. Arber, V. M. Nakariakov

The interaction of a weakly nonlinear Alfvénic pulse with an Alfvén speed inhomogeneity in the direction perpendicular to the magnetic field is investigated. Identically to the phase mixing experienced by a harmonic Alfvén wave, sharp transverse gradients are generated in the pulse by the inhomogeneity. In the initial stage of the evolution of an initially p

D. Tsiklauri, V. M. Nakariakov

A model interpreting variations of EUV brightness upward propagating in solar coronal loops as slow magnetoacoustic waves is developed. A loop is considered to have a non-zero plane inclination angle and offset of circular loop centre from the baseline. The model also incorporates effects of dissipation and gravitational stratification. A linear evolutionary

R. Enomoto, S. Hara, CANGAROO collaboration

CANGAROO-III is an Imaging Atmospheric Cherenkov Telescope (IACT) array of four 10 m telescopes for very high energy (sub-TeV) gamma-ray astronomy. A design study of the CANGAROO-III telescope system was carried out using the Monte Carlo technique in order to optimize the pixel size and the telescope spacing. Studies were also made of observations at low ele

Anwesh Mazumdar, H. M. Antia

It has been shown that a discontinuity in the derivatives of the sound speed at the edge of the convective regions inside a star gives rise to a characteristic oscillatory signal in the frequencies of stellar oscillations. This oscillatory signal has been suggested as a means to study the base of the outer convection zone in low mass stars and possibly the o

Jian-Min Wang

The strong correlation between the mass of the central supermassive black hole (SMBH) and the bulge in some galaxies and quasars implies that the formation of the black hole is somehow linked to the bulge. The measurement of metallicity by NV/CIV or NV/HeII in quasars allows to discuss a possible way of formation of the black hole. In this Letter we trace th

Paul Martini, Richard W. Pogge, Swara Ravindranath, Jin H. An

We present near-infrared J and H surface photometry of 24 of the nearby Seyfert 1.8, 1.9 and 2 galaxies from the CfA Seyfert sample. The excellent angular resolution of HST probes spatial scales as small as tens of parsecs in most of these AGN and is sensitive to the presence of nuclear bars and other potential signatures of the AGN fueling process that chan

B. Lehmann-Dronke, A. Schäfer

Motivated by the possibility to use high intensity neutrino beams for neutrino-nucleon scattering experiments we analyze charged current induced exclusive meson production within the framework of generalized parton distributions. The cross section for hard exclusive D_s production is estimated in this formalism to leading order in QCD. The integrated cross s

B. Melic, B. Nizic, K. Passek

We briefly review the calculational procedure for the PQCD prediction for hard exclusive quantities and reconsider the problem of the factorization scale dependence.

Per Arne Rikvold, Miroslav Kolesik

Analytical arguments and dynamic Monte Carlo simulations show that the microstructure of field-driven Solid-on-Solid interfaces depends strongly on the dynamics. For nonconservative dynamics with transition rates that factorize into parts dependent only on the changes in interaction energy and field energy, respectively (soft dynamics), the intrinsic interfa

A. B. Dzyubenko

An operator formalism is developed for a description of charged electron-hole complexes in magnetic fields. A novel unitary transformation of the Hamiltonian that allows one to partially separate the center-of-mass and internal motions is proposed. We study the operator algebra that leads to the appearance of new effective particles, electrons and holes with

Jonathan Bagger, Ioannis Giannakis

In this paper we consider superstring propagation in a nontrivial NS-NS background. We deform the world sheet stress tensor and supercurrent with an infinitesimal B_{μν} field. We construct the gauge-covariant super-Poincare generators in this background and show that the B_{μν} field spontaneously breaks spacetime supersymmetry. We find that the gauge-covar

C. Giunti

Using the model independent method of Villante, Fiorentini, Lisi, Fogli, Palazzo, and the rates measured in the SNO and Super-Kamiokande solar neutrino experiment, we calculate the amount of active nu_mu or nu_tau present in the flux of solar neutrinos on Earth. We show that the probability of nu_e->nu_{mu,tau} transitions is larger than zero at 99.89% CL. W

Mahendra K. Verma

Renormalized viscosity, renormalized resistivity, and various energy fluxes are calculated for helical magnetohydrodynamics using perturbative field theory. The calculation is to first-order in perturbation. Kinetic and magnetic helicities do not affect the renormalized parameters, but they induce an inverse cascade of magnetic energy. The sources for the th

Carlo Fulvi Mari

A model of the columnar functional organization of neocortical association areas is studied. The neuronal network is composed of many Hebbian autoassociators, or modules, each of which interacts with a relatively small number of the others. Every module encodes and stores a number of elementary percepts, or features. Memory items, or patterns, are peculiar c

Steven Schulz, Curtis Struck

We present new three dimensional, hydrodynamic simulations of the ram pressure stripping of disc galaxies via interaction with an hot intracluster medium (ICM). The simulations were carried with the smoothed-particle hydrodynamics, adaptive mesh 'Hydra' code (SPH-A$P^3$M), with model galaxies consisting of dark halo, and gas and stellar disc componen

Yosuke Uehara

We propose that right-handed neutrinos are very long-lived dark matter. The long lifetime is realized by the separation of the wavefunction of right-handed neutrinos and that of other fermions in an extra dimension. Such long-lived and superheavy dark matter can naturally explain observed ultra high energy cosmic rays above the GZK cutoff (5 * 10^{19} eV) an

Ian I. Kogan, Stavros Mouslopoulos, Antonios Papazoglou, Graham G. Ross

We study bulk fields in various multi-brane models with localized gravity. In the case of spin 0, 1/2 and 3/2 fields, the non-trivial background geometry itself can induce (multi-) localization of the zero modes along the extra dimension. The addition of appropriate mass terms controls the strength or/and the position of this localization and can induce (mul

David Merritt

The orientation of a massive binary undergoes a random walk due to gravitational encounters with field stars. The rotational diffusion coefficient for a circular-orbit binary is derived via scattering experiments. The binary is shown to reorient itself by an angle of order (m/M)^1/2 during the time that its semi-major axis shrinks appreciably, where M is the

Philippe Brax, Adam Falkowski, Zygmunt Lalak

We consider five-dimensional brane worlds with N=2 gauged supergravity in the bulk coupled supersymmetrically to two boundary branes at the fixed points of a Z_2 symmetry. We analyse two mechanisms that break supersymmetry either by choosing flipped fermionic boundary conditions on the boundary branes or by modifying the gravitino variation to include both Z

Florida Estrella, Richard McClatchey, Norbert Toth, Zsolt Kovacs

One of the main factors driving object-oriented software development in the Web- age is the need for systems to evolve as user requirements change. A crucial factor in the creation of adaptable systems dealing with changing requirements is the suitability of the underlying technology in allowing the evolution of the system. A reflective system utilizes an op

Abraham Loeb

If the current energy density of the universe is indeed dominated by a cosmological constant, then high-redshift sources will remain visible to us only until they reach some finite age in their rest-frame. The radiation emitted beyond that age will never reach us due to the acceleration of the cosmic expansion rate, and so we will never know what these sourc

Tokuzo Shimada, Shou Tsukada

We study how periodicity manifestations recently found in the turbulent globall coupled maps depend on the global feature of the couplings. We examine three non-locally coupled map models. In the first two, the all-to-all interaction is maintained but the coupling decreases with distance in a power and an exponential law. In the third, the interaction is uni

Ho Trung Dung, Ludwig Knöll, Dirk-Gunnar Welsch

By making use of the Green function concept of quantization of the electromagnetic field in Kramers--Kronig consistent media, a rigorous quantum mechanical derivation of the rate of intermolecular energy transfer in the presence of arbitrarily shaped, dispersing, and absorbing material bodies is given. Applications to bulk material, multi-slab planar structu

R. Piasecki, A. Plastino

Within the framework on non-extensive thermostatistics we revisit the recently advanced q-duality concept. We focus our attention here on a modified q-entropic measure of the spatial inhomogeneity for binary patterns. At a fixed length-scale this measure exhibits a generalised duality that links appropriate pairs of q and q&#39; values. The simplest q <-> q&

Vitor Cardoso, Jose&#39; P. S. Lemos

We study the quasi-normal modes (QNM) of scalar, electromagnetic and gravitational perturbations of black holes in general relativity whose horizons have toroidal, cylindrical or planar topology in an asymptotically anti-de Sitter (AdS) spacetime. The associated quasinormal frequencies describe the decay in time of the corresponding test field in the vicinit

P. Gallo, M. A. Ricci, M. Rovere

A Molecular Dynamics simulation of the microscopic structure of water confined in a silica pore is presented. A single cavity in the silica glass has been modeled as to reproduce the main features of the pores of real Vycor glass. A layer analysis of the site-site radial distribution functions evidence the presence in the pore of two subsets of water molecul

Niall MacKay, Ben Short

An informal introduction to our recent work on the principal chiral model with boundary. We found that both classically integrable boundary conditions and quantum boundary S-matrices were classified by the symmetric spaces G/H. The connection is explained by the presence of a twisted Yangian algebra of non-local charges.

P. Gallo, R. Pellarin, M. Rovere

Molecular dynamics simulations of a Lennard-Jones binary mixture confined in a disordered array of soft spheres are presented. The single particle dynamical behavior of the glass former is examined upon supercooling. Predictions of mode coupling theory are satisfied by the confined liquid. Estimates of the crossover temperature are obtained by power law fit

V. P. Mineev, P. L. Krotkov

The temperature dependence of paramagnetic susceptibility of the superfluid ^{3}He-B in aerogel is found. Calculations have been performed for an arbitrary phase shift of s-wave scattering in the framework of BCS weak coupling theory and the simplest model of aerogel as an aggregate of homogeneously distributed ordinary impurities. Both limiting cases of the

Jun-ichirou Koga

We investigate asymptotic symmetries regularly defined on spherically symmetric Killing horizons in the Einstein theory with or without the cosmological constant. Those asymptotic symmetries are described by asymptotic Killing vectors, along which the Lie derivatives of perturbed metrics vanish on a Killing horizon. We derive the general form of asymptotic K

UKQCD Collaboration, A. C. Irving, C. McNeile, C. Michael

We report on determinations of the low-energy constants alpha5 and alpha8 in the effective chiral Lagrangian at O(p^4), using lattice simulations with N_f=2 flavours of dynamical quarks. Precise knowledge of these constants is required to test the hypothesis whether or not the up-quark is massless. Our results are obtained by studying the quark mass dependen

Steve van Straaten, Michiel van der Klis, Tiziana di Salvo, Tomaso Belloni

We present the results of a multi-Lorentzian fit to the power spectra of two kilohertz QPO sources; 4U 0614+09 and 4U 1728-34. This work was triggered by recent results of a similar fit to the black-hole candidates (BHCs) GX 339-4 and Cyg X-1 by Nowak in 2000. We find that one to six Lorentzians are needed to fit the power spectra of our two sources. The use

Erel Granot

In this paper we use a simple straightforward technique to investigate the emergence of a bound state in a weakly bent wire. We show that the bend behaves like an infinitely shallow potential well, and in the limit of small bending angle and low energy the bend can be presented by a simple 1D delta function potential.

X. Y. Xia, S. J. Xue, S. Mao, Th. Boller

We report X-ray observations of the field containing the ultraluminous IRAS galaxy Mrk~273 Using the ACIS-S3 instrument on board Chandra. The high resolution X-ray image, for the first time, reveals a compact hard X-ray nucleus in Mrk~273. Its X-ray energy distribution is well described by a heavily obscured power-law spectrum plus a narrow $\Feka$ emission

A. I. Molev, E. Ragoucy

We study a class of algebras B(n,l) associated with integrable models with boundaries. These algebras can be identified with coideal subalgebras in the Yangian for gl(n). We construct an analog of the quantum determinant and show that its coefficients generate the center of B(n,l). We develop an analog of Drinfeld&#39;s highest weight theory for these algebr

S. Kalyana Rama

We study the dynamical consequences of Maggiore&#39;s unique generalised uncertainty principle (GUP). We find that it leads naturally, and generically, to novel consequences. In the high temperature limit, there is a drastic reduction in the degrees of freedom, of the type found, for example, in strings far above the Hagedorn temperature. In view of this, th

Shoichi Ichinose

Properties of the domain wall (kink) solution in the 5 dimensional Randall-Sundrum model are examined both {\it analytically} and {\it numerically}. The configuration is derived by the bulk Higgs mechanism. We focus on 1) the convergence property of the solution, 2) the stableness of the solution, 3) the non-singular property of the Riemann curvature, 4) the

M. Wakamatsu

Theoretical predictions are given for the strange sea distributions in the nucleon based on the flavor SU(3) chiral quark soliton model, with emphasis upon the asymmetry of quark and antiquark distributions. We find that the quark-antiquark asymmetry of the strange sea is much larger for the longitudinally polarized distribution functions than for the unpola

Blazenka Melic, Bene Nizic, Kornelija Passek

The NLO Brodsky-Lepage-Mackenzie (BLM) scale for the pion transition form factor has been determined. To achieve that, a consistent calculation up to nf-proportional NNLO contributions to both the hard-scattering amplitude and the perturbatively calculable part of the pion distribution amplitude has been performed. By combining and matching the results obtai

A. K. Svinin

It is shown that some special reduction of infinite 1D Toda lattice gives differential constraints compatible with the Kaup -- Broer system. A family of the travelling wave solutions of the Kaup -- Broer system and its higher version is constructed.

S. L. Adler, D. C. Brody, T. A. Brun, L. P. Hughston

Stochastic models for quantum state reduction give rise to statistical laws that are in most respects in agreement with those of quantum measurement theory. Here we examine the correspondence of the two theories in detail, making a systematic use of the methods of martingale theory. An analysis is carried out to determine the magnitude of the fluctuations ex

A. Marchewka, Zeev Schuss

We consider the evolution of Green&#39;s function of the one-dimensional Schrödinger equation in the presence of the complex potential $-ikδ(x)$. Our result is the construction of an explicit time-dependent solution which we use to calculate the time-dependent survival probability of a quantum particle. The survival probability decays to zero in finite time,

N. David Mermin

Sir Rudolph Peierls, in a reply to John Bell&#39;s last critique of the state of our understanding of quantum mechanics, maintained that it is easy to give an acceptable account of the physical significance of the quantum theory. The key is to recognize that all the density matrix characterizing a physical system ever represents is knowledge about that syste

Michael J. W. Hall

The Heisenberg inequality ΔX ΔP \geq \hbar/2 can be replaced by an exact equality, for suitably chosen measures of position and momentum uncertainty, which is valid for all wavefunctions. The statistics of complementary observables are thus connected by an ``exact&#39;&#39; uncertainty relation.

John Calsamiglia, Stephen M. Barnett, Norbert Lütkenhaus

We present a novel attack on quantum key distribution based on the idea of adaptive absorption [calsam01]. The conditional beam splitting attack is shown to be much more efficient than the conventional beam spitting attack, achieving a performance similar to the, powerful but currently unfeasible, photon number splitting attack. The implementation of the con

Piotr Badziag, Piotr Deuar, Michal Horodecki, Pawel Horodecki

We argue that a complete characterisation of quantum correlations in bipartite systems of many dimensions may require a quantity which, even for pure states, does not reduce to a single number. Subsequently, we introduce multi-dimensional generalizations of concurrence and find evidence that they may provide useful tools for the analysis of quantum correlati

Michael J. W. Hall

The Heisenberg inequality ΔX ΔP \geq \hbar/2 can be replaced by an exact equality, for suitably chosen measures of position and momentum uncertainty, which is valid for all wavefunctions. The significance of this &#34;exact&#34; uncertainty relation is discussed, and results are generalised to angular momentum and phase, photon number and phase, time and fre

F. van Lingen, R. McClatchey, P. v/d Stok, I. Willers

Within research institutions like CERN (European Organization for Nuclear Research) there are often disparate databases (different in format, type and structure) that users need to access in a domain-specific manner. Users may want to access a simple unit of information without having to understand detail of the underlying schema or they may want to access t

Sanjay K. Ghosh, Byron K. Jennings

The nuclear density of states plays an important role in nuclear reactions. At high energies, above a few MeV, the nuclear density of states is well described by a formula that depends on the smooth single particle density of states at the Fermi surface, the nuclear shell correction and the pairing energy. In this paper we present an analysis of the low ener

M. C. Martínez, J. A. Caballero, T. W. Donnelly

The relativistic mean field approach is applied to the description of coincidence $A(e,e&#39;p)B$ reactions where both the incident electron beam and knockout proton are polarized. Effects introduced by the dynamical enhancement of the lower components of the bound nucleon wave function are analyzed within RPWIA for the polarized responses and transferred po

Aurel Bulgac, Andreas Wirzba

Using ensembles of two, three and four spheres immersed in a fermionic background we evaluate the (integrated) density of states and the Casimir energy. We thus infer that for sufficiently smooth objects, whose various geometric characteristic lengths are larger then the Fermi wave length one can use the simplest semiclassical approximation (the contribution

EOS Collaboration, B. K. Srivastava

A systematic analysis of the moments of the fragment size distribution has been carried out for the multifragmentation (MF)of 1A GeV Au, La, and Kr on carbon. The breakup of Au and La is consistent with a continuous thermal phase transition. The data indicate that the excitation energy per nucleon and isotopic temperature at the critical point decrease with

Sitabhra Sinha, David J. Christini

Reentry around non-conducting ventricular scar tissue, which often causes lethal arrhythmias, is typically treated by rapid stimulation from an implantable defibrillator. However, the mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we studied pacing of anatomical reentry in 1-D and 2-D excitable cardiac me

Saburo Kakei, Yasuhiro Ohta

We present a novel differential-difference system in (2+1)-dimensional space-time (one discrete, two continuum), arisen from the Bogoyavlensky&#39;s (2+1)-dimensional KdV hierarchy. Our method is based on the bilinear identity of the hierarchy, which is related to the vertex operator representation of the toroidal Lie algebra $\sl_2^{tor}$.

Lei Yang, Yang Kongqing

This paper gives a 2D hamonic lattices model with missing bond defects, when the capacity ratio of defects is enough large, the temperature gradient can be formed and the finite heat conduction is found in the model. The defects in the 2D harmonic lattices impede the energy carriers free propagation, by another words, the mean free paths of the energy carrie

Saburo Kakei, Takeshi Ikeda, Kanehisa Takasaki

The hierarchy structure associated with a (2+1)-dimensional Nonlinear Schroedinger equation is discussed as an extension of the theory of the KP hierarchy. Several methods to construct special solutions are given. The relation between the hierarchy and a representation of toroidal Lie algebras are established by using the language of free fermions. A relatio

J. -H. Evertse, P. Moree, C. L. Stewart, R. Tijdeman

We show that for each n-tuple of positive rational integers (a_1,..,a_n) there are sets of primes S of arbitrarily large cardinality s such that the solutions of the equation a_1x_1+...+a_nx_n=1 with the x_i all S-units are not contained in fewer than exp((4+o(1))s^{1/2}(log s)^{-1/2}) proper linear subspaces of C^n. This generalizes a result of Erdos, Stewa

Wilhelm Winter

We introduce the completely positive rank, a notion of covering dimension for nuclear $C^*$-algebras and analyze some of its properties. The completely positive rank behaves nicely with respect to direct sums, quotients, ideals and inductive limits. For abelian $C^*$-algebras it coincides with covering dimension of the spectrum and there are similar results

Michael A. Dritschel, Scott McCullough

All operator algebras have (not necessarily irreducible) boundary representations. A unital operator algebra has enough such boundary representations to generate its C*-envelope.

F. Ngakeu, S. Majid, D. Lambert

We study the noncommutative Riemannian geometry of the alternating group $A_4=(Z_2 \times Z_2)\cross Z_3$ using a recent formulation for finite groups. We find a unique `Levi-Civita&#39; connection for the invariant metric, and find that it has Ricci-flat but nonzero Riemann curvature. We show that it is the unique Ricci-flat connection on $A_4$ with the sta

Anne Schilling

q-Supernomial coefficients are generalizations of the q-binomial coefficients. They can be defined as the coefficients of the Hall-Littlewood symmetric function in a product of the complete symmetric functions or the elementary symmetric functions. Hatayama et al. give explicit expressions for these q-supernomial coefficients. A combinatorial expression as t

Ruslan Sharipov

Newtonian, Lagrangian, and Hamiltonian dynamical systems are well formalized mathematically. They give rise to geometric structures describing motion of a point in smooth manifolds. Riemannian metric is a different geometric structure formalizing concepts of length and angle. The interplay of Riemannian metric and its metric connection with mechanical struct

Oded Schramm

Let $A$ be an arc on the boundary of the unit disk $U$. We prove an asymptotic formula for the probability that there is a percolation cluster $K$ for critical site percolation on the triangular grid in $U$ which intersects $A$ and such that 0 is surrounded by $K\cup A$.

Vladimir Kondratiev, Mikhail Shubin

We provide sufficient conditions for the discreteness of spectrum for magnetic Schrödinger operators. They generalize the classical result by K.Friedrichs (1934) and earlier results by J.Avron, I.Herbst and B.Simon (1978), A.Dufresnoy (1983) and A.Iwatsuka (1990) which were obtained in the absence of electric field. Our conditions are formulated as condition

Mikhail Shubin

We prove essential self-adjointness for semi-bounded below magnetic Schrödinger operators on complete Riemannian manifolds with a given positive smooth measure which is fixed independently of the metric. Some singularities of the scalar potential are allowed. This is an extension of the Povzner--Wienholtz--Simader theorem. The proof uses the scheme of Wienho

Winfried Bruns, Joseph Gubeladze

We investigate similarities between the category of vector spaces and that of polytopal algebras, containing the former as a full subcategory. In Section 2 we introduce the notion of a polytopal Picard group and show that it is trivial for fields. The coincidence of this group with the ordinary Picard group for general rings remains an open question. In Sect

Michael Dine

For physicists, recent developments in astrophysics and cosmology present exciting challenges. We are conducting &#34;experiments&#34; in energy regimes some of which will be probed by accelerators in the near future, and others which are inevitably the subject of more speculative theoretical investigations. Dark matter is an area where we have hope of makin

M. Aguado, M. Asorey, A. Wipf

There is a Nahm transform for two-dimensional gauge fields which establishes a one-to-one correspondence between the orbit space of U(N) gauge fields with topological charge k defined on a torus and that of U(k) gauge fields with charge N on the dual torus. The main result of this paper is to show that a similar duality transform cannot exist for CPn instant

Edmond L. Berger, Jianwei Qiu, Xiaofei Zhang

We derive a new factorization formula in perturbative quantum chromodynamics for the Drell-Yan massive lepton-pair cross section as a function of the transverse momentum $Q_T$ of the pair. When $Q_T$ is much larger than the pair&#39;s invariant mass $Q$, this factorization formula systematically resums the logarithmic contributions of the type $α_s^m \ln^m(Q

O. Panella, M. Cannoni, C. Carimalo, Y. N. Srivastava

The lepton number violating signal of like-sign-dileptons (LSD), p p \to \ell^\pm\ell^\pm + 2 jets, is investigated within a model of mixing in the neutrino sector assuming the existence of heavy Majorana neutrino states with a left--handed coupling to the light leptons. The LSD signal receives contributions both from the resonant production of a heavy Major

Yasuhiro Daikoku

The recent measurement of the muon anomalous magnetic dipole moment shows 2.6$σ$ deviation of $a_μ$ from the standard model prediction which can be explained by a chargino-sneutrino loop correction in the supersymmetric models. In this paper we consider extra U(1) models where the $μ$ parameter is radiatively generated. This model predicts the sign of $μ$ is

Claudio Coriano, Alon E. Faraggi

Advancing QCD toward astroparticle applications generates new challenges for perturbation theory, such as the presence of large evolution scales with sizeable scaling violations involving both the initial and the final state of a collision. Possible applications in the context of Ultra High Energy Cosmic Rays (UHECR) of these effects are discussed.

Emili Bagan, Martin Lavelle, David McMullan, Shogo Tanimura

The possibility of constructing charged particles in gauge theories has long been the subject of debate. In the context of QED we have shown how to construct operators which have a particle description. In this paper we further support this programme by showing how the screening interactions arise between these charges. Unexpectedly we see that there are two

Hans-Christian Pauli

This work addresses more to the technical rather than to the physical problem, how to calculate analytically the form factor $F(Q)$, the associated mean-square radius $<r^2>$, and the distribution function $Φ(x,Q^2)$ for a given light-cone wave function $Ψ_{q\bar q}(x,\vec k_{\perp})$ of the pion. They turn out to be functions of only one dimensionless param

Alberto Accardi

At ultra-relativistic energies the minijet production in heavy-ion collisions becomes sensitive to semi-hard parton rescatterings in the initial stages of the process. As a result global characteristics of the event, like the initial minijet density, become rather insensitive on the infrared cutoff that separates hard and soft interactions. This allows to de

Einan Gardi, Georges Grunberg

The large-order behaviour of QCD is dominated by renormalons. On the other hand renormalons do not occur in conformal theories, such as the one describing the infrared fixed-point of QCD at small beta_0 (the Banks--Zaks limit). Since the fixed-point has a perturbative realization, all-order perturbative relations exist between the conformal coefficients, whi

A. Nehme, P. Talavera

We evaluate the matrix elements for the processes pi^0 K^0 -> pi^0 K^0 and pi^- K^+ -> pi^0 K^0 in the presence of isospin breaking terms at leading and next-to-leading order. As a direct application the releveant combination of the S-wave scattering lengths involved in the pion-kaon atom lifetime is determined. We discuss the sensitivity of the results with

M. Czakon, J. Gluza, M. Zralek

A formal proof is given that in a see-saw type neutrino mass matrix with only two neutrino mass scales ($m_D \ll m_R$) and the maximal rank of $m_{R(D)}$, we can not get a fourth light sterile neutrino.

P. M. Ferreira

We calculate the one-loop contributions to the tau slepton masses in the Minimal Supersymmetric Standard Model in the effective potential approach. For the majority of parameter space under study, those corrections are shown to elevate the value of the lightest stau mass.

Zhi-zhong Xing

The first observation of the color-suppressed decay mode \bar{B}^0_d --> D^(*)0 π^0 by the Belle and CLEO Collaborations makes a quantitative analysis of the isospin relations for the amplitudes of B --> D^(*)πpossible. The strong (isospin) phase difference in B --> Dπtransitions is found to be about 29^\circ by use the Belle data or 26^\circ by use of the C

Rajiv V. Gavai, Sourendu Gupta, R. Lacaze

We study physics at temperatures just above the QCD phase transition (Tc) using chiral (overlap) Fermions in the quenched approximation of lattice QCD. Exact zero modes of the overlap Dirac operator are localized and their frequency of occurrence drops with temperature. This is closely related to axial U(1) symmetry, which remains broken up to 2Tc. After sub

T. Alderweireld

During the LEP2 operation, the 4 LEP experiments have collected data at centre-of-mass energies up to 209 GeV. Those data have been analysed in the search of charginos, neutralinos and sfermions in the framework of the Minimal Supersymmetric Standard Model (MSSM) with R-parity conservation and assuming the lightest neutralino to be the Lightest Supersymmetri

Andrzej Sandacz, Oleg A. Grajek, Murray Moinester, Eli Piasetzky

We examine the potential of the COMPASS experiment at CERN to study color transparency via exclusive vector meson production in hard muon-nucleus scattering. It is demonstrated that COMPASS has high sensitivity to test this important prediction of perturbative QCD.

V. E. Kuzmichev, V. V. Kuzmichev

Old and new puzzles of cosmology are reexamined from the point of view of quantum theory of the universe developed here. It is shown that in proposed approach the difficulties of the standard cosmology do not arise. The theory predicts the observed dimensions of the nonhomogeneities of matter density and the amplitude of the fluctuations of the cosmic backgr

Mladen Prester

In cuprate superconductors superconductivity develops as a unique cross over between the two extremal phases characterizing these compounds. The extremal phases are known to be an antiferromagnetic (AF) Mott insulator one, on one side, and a non-superconducting itinerant metal on the other. Numerous inelastic neutron scattering studies on underdoped samples

Andrew P. Iyengar, Ying-Jer Kao, Qijin Chen, K. Levin

We demonstrate that the observed dependences of $T_c$ and $T^*$ on small magnetic fields can be readily understood in a precursor superconductivity approach to the pseudogap phase. In this approach, the presence of a pseudogap at $T_c$ (but not at $T^*$) and the associated suppression of the density of states lead to very different sensitivities to pair-brea