January 2001 arXiv papers — page 21

Barbara M. Terhal

We review the criteria for separability and quantum entanglement, both in a bipartite as well as a multipartite setting. We discuss Bell inequalities, entanglement witnesses, entropic inequalities, bound entanglement and several features of multipartite entanglement. We indicate how these criteria bear on the experimental detection of quantum entanglement.

An Min Wang

We present a possible candidate of construction of a scalable, uniform and universal quantum network, which is built from quantum gates to elements of quantum circuit, again to quantum subnetworks and finally to an entire quantum network. Our scheme can overcome some difficulties of the existing schemes and makes improvements to different extent in the scale

Z. Papp, S. L. Yakovlev, C-. Y. Hu, J. Darai

A novel method for calculating resonances in three-body Coulombic systems is presented. The Faddeev-Merkuriev integral equations are solved by applying the Coulomb-Sturmian separable expansion method. To show the power of the method we calculate resonances of the three-$α$ and the $H^-$ systems.

Z. Junhao

Quantum mechanics take the sum of first finite order approximate solutions of time-dependent perturbation to substitute the exact solution. From the point of mathematics, it may be correct only in the convergent region of the time-dependent perturbation series. Where is the convergent region of this series? Quantum mechanics did not answer this problem. Howe

John E Heighway

The purpose of the present paper is to extend the Variable Rest Mass (VRM) Interpretation and the telemetric system of measurment to the case of stationary but non-static spacetimes, especially the Kerr solution.

V. A. Dzuba, V. V. Flambaum, J. S. M. Ginges

We have performed ab initio mixed-states and sum-over-states calculations of parity nonconserving (PNC) electric dipole (E1) transition amplitudes between s-d electron states of Cs, Fr, Ba II, and Ra II. For the lower states of these atoms we have also calculated energies, E1 transition amplitudes, and lifetimes. We have shown that PNC E1 transition amplitud

Robert A. Herrmann

In this paper, the set of all physical theories is represented by a countable collection of consequence operators. It is established that in the Grundlegend Structure, a nonstandard structure, there exists a function S such that for any subset W of L, S selects an ultralogic C such that C(*W) restrictred to L is a unification for the set of all physical theo

Malcolm Butler, Jiunn-Wei Chen

The proton-proton fusion process p p->d e^+ nu_e is calculated at threshold to fifth order in pionless effective field theory. There are two unknown two-body currents contributing at the second and fourth orders. Combined with the previous results for neutrino-deuteron and antineutrino-deuteron scattering, computed to third order in the same approach, we con

S. Yildirim, A. Gokalp, O. Yilmaz, S. Ayik

Collisional damping widths of giant monopole and quadrupole excitations for $^{120}$Sn and $^{208}$Pb at zero and finite temperatures are calculated within Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Skyrme and Gogny forces, and are compared with each other. The results for the

Jeff Moehlis

The effect of additive white noise on a model for bursting behavior in large aspect-ratio binary fluid convection is considered. Such bursts are present in systems with nearly square symmetry and are the result of heteroclinic cycles involving infinite amplitude states created when the square symmetry is broken. A combination of numerical results and analyti

E. S. Gutshabash

The boundary problem for a two-dimensional elliptical equation -sinh-Gordon has been investigated. The exact solutions have been found and identities of traces have been proposed. The application of the problem to the model of the Coulomb's plasma with the negative temperature has been considered.

P. Leboeuf, A. G. Monastra, O. Bohigas

The properties of a fictitious, fermionic, many-body system based on the complex zeros of the Riemann zeta function are studied. The imaginary part of the zeros are interpreted as mean-field single-particle energies, and one fills them up to a Fermi energy $E_F$. The distribution of the total energy is shown to be non-Gaussian, asymmetric, and independent of

M. Daoud, M. R. Kibler

The Hamiltonian for a fractional supersymmetric oscillator is derived from three approaches. The first one is based on a decomposition in which a Q-uon gives rise to an ordinary boson and a k-fermion (a k-fermion being an object interpolating between boson and fermion). The second one starts from a generalized Weyl-Heisenberg algebra. Finally, the third one

Par Kurlberg, Zeev Rudnick

We study the value distribution and extreme values of eigenfunctions for the ``quantized cat map''. This is the quantization of a hyperbolic linear map of the torus. In a previous paper it was observed that there are quantum symmetries of the quantum map - a commutative group of unitary operators which commute with the map, which we called ``Hecke op

J. Barros-Neto, Fernando Cardoso

Partial Fourier transforms are used to find explicit formulas for two remarkable fundamental solutions for a generalized Tricomi operator. These fundamental solutions reflect clearly the mixed type of the operator. In order to prove these results, we establish explicit formulas for Fourier transforms of some type of Bessel functions.

Dan Burghelea

Witten-Helffer-Sjöstrand theory is an addition to Morse theory and Hodge-de Rham theory for Riemannian manifolds and considerably improves on them by injecting some spectral theory of elliptic operators. It can serve as a general tool to prove results about comparison of numerical invariants associated to compact manifolds analytically, i.e. by using a Riema

Michael Britze, Marc A. Nieper

In this article we investigate Hirzebruch-Riemann-Roch formulae for line bundles on irreducible symplectic Kähler manifolds. As Huybrechts has shown, for every irreducible complex Kähler manifold $X$ of dimension $2n$, there are numbers $a_0, a_2, ..., a_{2n}$ such that $χ(L) = \sum_{k = 0}^n a_{2k}/(2k)! q_X(c_1(L))^k$ for the Euler characteristic of a line

Bernd Ammann

We prove upper and lower bounds for the eigenvalues of the Dirac operator and the Laplace operator on 2-dimensional tori. In particluar we give a lower bound for the first eigenvalue of the Dirac operator for non-trivial spin structures. It is the only explicit estimate for eigenvalues of the Dirac operator known so far that uses information about the spin s

S. Bouarroudj, H. Gargoubi

Let $Σ$ be an open Riemann surface and $Hol (Σ)$ be the Lie algebra of holomorphic vector fields on $Σ.$ We fix a projective structure (i.e. a local $SL_2(C)-$structure) on $Σ.$ We calculate the first group of cohomology of $Hol(Σ)$ with coefficients in the space of linear holomorphic operators acting on tensor densities, vanishing on the Lie algebra $SL_2 (

J. Barcelos-Neto

We embed the Wess-Zumino (WZ) model in a wider superspace than the one described by chiral and anti-chiral superfields.

Philip D. Mannheim

In a recent paper Shiromizu, Maeda and Sasaki derived the gravitational equations of motion which would hold on a brane which is embedded in a higher dimensional bulk spacetime, showing that even when the Einstein equations are imposed in the bulk, nonetheless the embedding leads to a modification of the Einstein equations on the brane. In this comment on th

M. M. Sheikh-Jabbari

The recently found non-critical open string theories is reviewed. These open strings, noncommutative open string theories (NCOS), arise as consistent quantum theories describing the low energy theory of D-branes in a background electric B-field in the critical limit. Focusing on the D3-brane case, we construct the most general (3+1) NCOS, which is described

Jeffrey A. Bowers, Joydip Kundu, Krishna Rajagopal, Eugene Shuster

We present a derivation of the gap equation for the crystalline color superconducting phase of QCD which begins from a one-loop Schwinger-Dyson equation written using a Nambu-Gorkov propagator modified to describe the spatially varying condensate. Some aspects of previous variational calculations become more straightforward when rephrased beginning from a di

T. M. Aliev, A. Ozpineci, M. Savci

Using the most general, model-independent form of effective Hamiltonian, the exclusive, rare $B \rar K^\ast ν\bar ν$ decay is analyzed. The sensitivity of the branching ratios and missing mass-squared spectrum to the new Wilson coefficients is discussed.

R. A. Alanakyan

In model independent way considered long-range interactions of the macroscopic objects under assumption that any particle of this objects interact with probe particle as $ A/r^n$. Also presented model-independent corrections to the Coulomb energy levels from regularised version of the potential $ A/r^n$.

O. D. Chernavskaya, E. L. Feinberg, I. I. Royzen

The possibility of unified description of hadron multiple production in heavy ion collisions over the wide energy interval, from few hundreds MeV/n at GSI/SIS through 11 GeV/n at BNL/AGS up to 160 GeV/n at CERN/SPS, has been emphasized recently by J. Cleymans and K. Redlich. They, and somewhat later B. Muller and J. Rafelski, treated this fact as an indicati

V. Bernard, N. Kaiser, Ulf-G. Meißner

We show that a recent claim (H.Haberzettl, Phys. Rev. Lett. 85 (2000) 3576) that one cannot extract the nucleon weak axial form factor G_A (t) from charged pion threshold electroproduction is incorrect. Thus previous calculations remain valid and threshold charged pion electroproduction experiments can indeed be used to determine G_A (t), and they should cer

F. V. Tkachov

Reported is a factorization theorem for large-s behavior of total cross sections obtained in a straightforward fashion from ordinary perturbation theory. The theorem extends the standard factorization results for the Bjorken and Drell-Yan processes. The obtaining of useful evolution equations is found to be problematic. A by-product is a direct method for sy

S. M. Ouellette

Applications imposing SU(3) chiral symmetry on non-relativistic field theory are considered. The first example is a calculation of the self-energy shifts of the spin-3/2 decuplet baryons in nuclear matter, from the chiral effective Lagrangian coupling octet and decuplet baryon fields. Special attention is paid to the self-energy of the delta baryon near the

Klaus Moenig

The possibilities to run with a linear collider at the Z-pole with high luminosity are examined. Apart from the implications on machine and detector the interest for electroweak and B-physics is discussed.

Adrian P. Gentle, Warner A. Miller

We briefly review past applications of Regge calculus in classical numerical relativity, and then outline a programme for the future development of the field. We briefly describe the success of lattice gravity in constructing initial data for the head-on collision of equal mass black holes, and discuss recent results on the efficacy of Regge calculus in the

Jozef Sima, Miroslav Sukenik

Incorporation of the Vaidya metric in the model of Expansive Nondecelerative Universe allows to localize the energy density of gravitational field that, subsequently, enables to determine the upper limit of stars mass. The upper limit decreases with cosmological time and at present is close to 30-fold of our Sun mass.

Miroslav Sukenik, Jozef Sima

Incorporation of the Vaidya metric in the model of Expansive Nondecelerative Universe allows to precisely localize gravitational energy for weak fields and obtain the components of the Einstein energy-momentum pseudotensor for strong gravitational fields. The components are identical to those calculated by Virbhadra.

A. T. Boothroyd, C. H. Gardiner, S. J. S. Lister, P. Santini

Neutron spectroscopic measurements of the magnetic excitations in PrO$_2$ reveal (1) sharp peaks characteristic of transitions between levels of the $4f^1$ configuration of Pr$^{4+}$ split by the cubic crystal field, and (2) broad bands of scattering centred near 30 meV and 160 meV. We present a simple model based on a vibronic Hamiltonian that accounts for

C. G. Bezerra, J. M. de Araujo, C. Chesman, E. L. Albuquerque

A theoretical study of the magnetization curves of quasiperiodic magnetic multilayers is presented. We consider structures composed by ferromagnetic films (Fe) with interfilm exchange coupling provided by intervening nonferromagnetic layers (Cr). The theory is based on a realistic phenomenological model, which includes the following contributions to the free

R. J. Christianson, R. L. Leheny, R. J. Birgeneau, R. W. Erwin

We report a neutron scattering study of the dynamic spin correlations in Rb$_2$MnF$_4$, a two-dimensional spin-5/2 antiferromagnet. By tuning an external magnetic field to the value for the spin-flop line, we reduce the effective spin anisotropy to essentially zero, thereby obtaining a nearly ideal two-dimensional isotropic antiferromagnet. From the shape of

Ilya Grinberg, Nicholas J. Ramer, Andrew M. Rappe

We generate a series of pseudopotentials to examine the relationship between pseudoatomic properties and solid-state results. We find that lattice constants and bulk moduli are quite sensitive to eigenvalue, total-energy difference and tail norm errors, and clear correlations emerge. These trends motivate our identification of two criteria for accurate trans

B. Leridon, A. Defossez, J. Dumont, J. Lesueur

Conductivity due to superconducting fluctuations studied in optimally doped YBa2Cu3O7-d films displays a stronger decay law in temperature than explainable by theory. A formula is proposed, which fits the data very well with two superconductive parameters, Tc and the coherence length ksi_c0, and an energy scale Delta*. This is also valid in underdoped materi

E. Kierlik, P. A. Monson, M. L. Rosinberg, L. Sarkisov

We study the interplay between hysteresis and equilibrium behavior in capillary condensation of fluids in mesoporous disordered materials via a mean-field density functional theory of a disordered lattice-gas model. The approach reproduces all major features observed experimentally. We show that the simple van der Waals picture of metastability fails due to

D. N. Aristov

We consider the small-angle multiple neutron scattering and a possibility of its model-free analysis by the inverse problem method. We show that the ill-defined problem is essentially regularized by use of a planar detector without a "beam-stop" facility. We analyze the obtained expressions with the examples of different models of scatterers.

Marti Pi, Agusti Emperador, Manuel Barranco, Francesca Garcias

We have investigated the structure of double quantum dots vertically coupled at zero magnetic field within local spin-density functional theory. The dots are identical and have a finite width, and the whole system is axially symmetric. We first discuss the effect of thickness on the addition spectrum of one single dot. Next, we describe the structure of coup

Xue Heng Zheng

New calculation reveals that E is constant in a thin layer across the Fermi surface, befitting the definition of energy gap parameter, Delta varies dramatically. The BCS self-consistent equation has a simple and exact solution, showing that the well-known ratio 3.5 must be replaced by 4. A simple formula is found to estimate energy gap from first principles

Yu. G. Naidyuk, K. Gloos, T. Takabatake

IVC characteristics as well as their derivatives were recorded for contacts on the base of CeNiSn, known as Kondo semiconductor, in the metallic and the tunnelling regime at temperatures between 0.1-8 K and in magnetic fields up to 8 T using mechanically controllable break junctions (MCBJ). It was found that CeNiSn behaves like a compound with typical metall

L. A. Falkovsky

We consider the localized phonon states created by defects of various geometries near the edge of an optical-phonon branch. The averaged Green's function is calculated to study the Raman line shape. The phonon scattering by the defects induces broadening and line shape asymmetry. The contribution of localized states to Raman spectra has a form of shoulde

R. G. Mints, Ilya Papiashvili

We report numerical simulations of magnetic flux patterns in asymmetric 45$^{\circ}$ [001]-tilt grain boundaries in YBa$_2$Cu$_3$O$_{7-x}$ superconducting films. The grain boundaries are treated as Josephson junctions with the critical current density $j_c(x)$ alternating along the junctions. We demonstrate the existence of Josephson vortices with fractional

Jose A. Magpantay

Open, dissipative systems subject to a random force are directly quantized. The starting point is the effective action derived using the method of Parisi-Sourlas. Since the effective action is second-order, the method of Ostrogradsky was used to quantize the system canonically. In the case of the harmonic oscillator, the relevant Green function can be comput

M. Kastner, M. Promberger

A recent paper by A. R. Lima, P. M. C. de Oliveira, and T. J. P. Penna [cond-mat/0002176; J. Stat. Phys. 99:691 (2000)], seems to contain at least two mistakes which deserve comment, one concerning the numerical data, the other being of a conceptual kind.

Kirk T. Korista, Michael R. Goad

We investigate the wavelength-dependent intensity and reverberation properties of the UV-optical diffuse continuum emission expected from broad emission line gas. The locally optimally emitting clouds picture is adopted, with the cloud distribution functions in gas density and distance from the ionizing source determined by a fit to the mean UV emission line

Anthony H. Minter, Felix J. Lockman, Glen I. Langston, Jennifer A. Lockman

New 21 cm HI observations have revealed a giant HI cloud in the Galactic plane that has unusual properties. It is quite well defined, about 150 pc in diameter at a distance of 5 kpc, and contains as much as 100,000 Solar Masses of atomic hydrogen. The outer parts of the cloud appear in HI emission above the HI background, while the central regions show HI se

Neal A. Miller, Frazer N. Owen

We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxie s in eighteen nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3 Mpc, which corresponds to 1.5 Abell radii and approximately four orders of magnitude in galaxy density. To create a truly useful catalog, we have collected optical spectra f

O. Doré, R. Teyssier, F. R. Bouchet, D. Vibert

The data analysis of current Cosmic Microwave Background (CMB) experiments like BOOMERanG or MAXIMA poses severe challenges which already stretch the limits of current (super-) computer capabilities, if brute force methods are used. In this paper we present a practical solution to the optimal map making problem which can be used directly for next generation

W. Coburn, W. A. Heindl, D. E. Gruber, R. E. Rothschild

We have discovered a ~29 keV Cyclotron Resonant Scattering Feature (CRSF) in the X-Ray spectrum of 4U 0352+309 (X Per) using observations taken with the Rossi X-Ray Timing Explorer. 4U 0352+309 is a persistent low luminosity (L_x = 4.2x10^34 ergs/s) X-ray pulsar, with a 837 s period and which accretes material from the Be star X Per. The X-Ray spectrum, unus

Gustavo E. Romero, Diego F. Torres, P. Benaglia, J. A. Combi

In a recent paper, Romero et al. (1999) have presented the results of a positional correlation analysis of the low-latitude unidentified gamma-ray sources in the Third EGRET catalog with complete lists of galactic objects like supernova remnants, early type stars with strong stellar winds, and OB associations (considered as pulsar tracers). We have now carri

Jacco Th. van Loon, A. A. Zijlstra, L. Kaper, G. F. Gilmore

The obscured OH/IR star IRAS05298-6957 in the LMC was recently noticed to be member of the small double cluster HS 327 that also contains a carbon star (van Loon et al., 1998, A&A 329, 169). Hence they are coeval and have (nearly) the same progenitor mass, which can only be understood if Hot Bottom Burning (HBB) has prevented IRAS05298-6957 from being a carb

C. E. Jones, Shantanu Basu, John Dubinski

We conduct an analysis of the shapes of molecular cloud cores using recently compiled catalogs of observed axis ratios of individual cores mapped in ammonia or through optical selection. We apply both analytical and statistical techniques to deproject the observed axis ratios in order to determine the true distribution of cloud core shapes. We find that neit

Jean-Loup Puget, Guilaine Lagache

The cosmic far-infrared background is now well measured from 140 micron to 1 mm. Uncertainties remain at 100 micron (and even more at 60 micron). These are dominated by limitations of the zodiacal model. The nature of sources dominating the background near its maximum are beginning to be studied through deep surveys carried out with ISOPHOT. These surveys sh

R. I. Hynes, P. A. Charles, C. A. Haswell, J. Casares

We present time-resolved spectroscopy of the soft X-ray transient XTE J2123-058 in outburst. A useful spectral coverage of 3700-6700A was achieved spanning two orbits of the binary, with single epoch coverage extending to \~9000A. The optical spectrum approximates a steep blue power-law, consistent with emission on the Rayleigh-Jeans tail of a hot black body

M. Almudena Prieto, Ana Pérez-García, José M. Rodríguez-Espinosa

The relation between the X-ray emission, the infrared emission and the coronal line emission in a sample of the brightest known Seyfert galaxies is analyzed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-infrared and the coronal line emission is found among the Seyfert type 2 objects studied in this work. Being bo

Coel Hellier

I present a variation on Osaki&#39;s tidal-thermal-instability model for SU UMa behavior. I suggest that in systems with the lowest mass ratios, the angular-momentum dissipation in an eccentric disk is unable to sustain the disk on the hot side of the thermal instability. This decoupling of the tidal and thermal instabilities in systems with q < 0.07 allows

S. Mereghetti, D. I. Cremonesi, J. Borkowski

We describe the INTEGRAL Burst Alert System (IBAS): the automatic software developed at the INTEGRAL Science Data Center to allow the rapid distribution of the coordinates of the Gamma-Ray Bursts detected by INTEGRAL. IBAS is implemented as a ground based system, working on the near-real time telemetry stream. It is expected that the system will detect more

R. I. Davies, M. Tecza, L. W. Looney, F. Eisenhauer

Progress in understanding the embedded stars in LkHa225 has been hampered by their variability, making it hard to compare data taken at different times, and by the limited resolution of the available data, which cannot probe the small scales between the two stars. In an attempt to overcome these difficulties, we present new near-infrared data on this object

D. Gotz, D. I. Cremonesi, S. Mereghetti

We have used the IBIS Simulator to produce preliminary response matrices for the ISGRI and PICsIT detectors in order to help understanding their scientific performances before the calibration results are available. The derived matrices, in a format compatible with the XSPEC spectral analysis package, have been tested by fitting simple models and then used to

Yaroslav Urzhumov

We re-derive hydrodynamical equations in General Relativity (GR) in the comoving reference frame for spherical symmetry and obtain from them the well-known but not explicitly derived Lagrangean equations in Special Relativity (SR), that is, for the case of weak gravitational fields. Explicit formulae are presented which relate General Relativistic independen

S. Charlot, M. Longhetti

We present a new model for computing consistently the line and continuum emission from galaxies, based on a combination of recent population synthesis and photoionization codes. We use effective parameters to describe the HII regions and the diffuse gas ionized by single stellar generations in a galaxy [...]. We calibrate the nebular properties of our model

G. Giovannini, W. D. Cotton, L. Feretti, L. Lara

A complete sample of 27 radio galaxies was selected from the B2 and 3CR catalogs, in order to study their properties on the milliarcsecond scale. In the Appendix of this paper we present new radio images for 12 of them. Thanks to the present data, all the sources in this sample have been imaged at mas resolution. We discuss the general results. In particular

Ping He, Zhen-Long Zou, Yuan-Zhong Zhang

Pure luminosity evolution models for galaxies provide an unacceptable fit to the redshifts and colors of faint galaxies. In this paper we demonstrate, using HST morphological number counts derived both from the $I_{814}$-band of WFPC2 in the Medium Deep Survey (MDS) and the Hubble Deep Field (HDF) and from the $H_{1.6}$-band of NICMOS, and ground-based spect

L. A. Pando Zayas, A. A. Tseytlin

We study supergravity solutions representing D3-branes with transverse 6-space having R x S^2 x S^3 topology. We consider regular and fractional D3-branes on a natural one-parameter extensions of the standard Calabi-Yau metrics on the singular and resolved conifolds. After imposing a Z_2 identification on an angular coordinate these generalized &#34;6-d coni

Metod Saniga

It is pointed out that the hierarchy of fractal dimensions characterizing transfinite heterotic string spacetimes bears a striking resemblance to the sequence of the number of lines lying on Del Pezzo surfaces.

S. Koziel, W. A. Majewski

A model of evolution of bipartite quantum state entanglement is studied. It involves recently introduced quantum block spin-flip dynamics on a lattice. We find that for initially separable states the considered evolution leads, in general, to entangled states. We also present a complete characterization of two-point correlation functions for that type of dyn

Adam W. Majewski

In this paper we present the novel qualities of entanglement of formation for general (so also infinite dimensional) quantum systems. A major benefit of our presentation is a rigorous description of entanglement of formation. In particular, we indicate how this description may be used to examine optimal decompositions. Illustrative examples showing the metho

Tateaki Yazawa, Tsuneo Suzuki

3D Georgi-Glashow model is studied on the lattice in the London limit in an infrared but an intermediate region before the screening appears. Abelian and instanton dominances are observed after abelian projections in a unitary gauge and roughly in the maximally abelian gauge. Using an inverse Monte-Carlo method, we determine an effective instanton action in

G. P. Berman, F. Borgonovi, G. Chapline, S. A. Gurvitz

We consider the process of a single-spin measurement using magnetic resonance force microscopy (MRFM) as an example of a truly continuous measurement in quantum mechanics. This technique is also important for different applications, including a measurement of a qubit state in quantum computation. The measurement takes place through the interaction of a singl

E. Knill, R. Laflamme, R. Martinez, C. Negrevergne

The smallest quantum code that can correct all one-qubit errors is based on five qubits. We experimentally implemented the encoding, decoding and error-correction quantum networks using nuclear magnetic resonance on a five spin subsystem of labeled crotonic acid. The ability to correct each error was verified by tomography of the process. The use of error-co

Alexander D. Panov

A numerical model of spontaneous decay continuously monitored by a distant detector of emitted particles is constructed. It is shown that there is no quantum Zeno effect in such quantum measurement if the interaction between emitted particle and detector is short-range and the mass of emitted particle is not zero.

V. A. Buslov

The supergenerator of superparamagnetic system quantum evolution is investigated in discrete orientation model (DOM). It is shown that the generator is J-self-adjoint one at the case of potential drift field agreed upon magnetic anisotropy of the sample investigated. Perturbation theory is used for spectral analysis. The qualitative dependence of resonance a

C. Tannous, A. Fessant

Combustion reaction kinetics models are used for the description of a special class of bursty Financial Time Series. The small number of parameters they depend upon enable financial analysts to predict the time as well as the magnitude of the jump of the value of the portfolio. Several Financial Time Series are analysed within this framework and applications

Nikolay A. Zabotin, Gennady A. Zhbankov, Eugene S. Kovalenko

The paper presents theoretical study of the influence of shape of the spatial spectrum of small-scale ionospheric irregularities on anomalous attenuation of HF radio waves caused by multiple scattering. Several spectrum models are considered. Relative contribution of different wave number regions of the spectrum is investigated. The analysis of numerical cal

Robert L. Griess, Gerald Höhn

The concept of a framed vertex operator algebra was studied in [DGH] (q-alg/9707008). This article is an analysis of all Virasoro frame stabilizers of the lattice VOA V for the E_8 root lattice, which is isomorphic to the E_8-level 1 affine Kac-Moody VOA V. We analyze the frame stabilizers, both as abstract groups and as subgroups of the Lie group Aut(V) = E

David Garber, Shmuel Kaplan, Mina Teicher

One of the most interesting questions about a group is if its word problem can be solved and how. The word problem in the braid group is of particular interest to topologists, algebraists and geometers, and is the target of intensive current research. We look at the braid group from a topological point of view (rather than a geometrical one). The braid group

M. R. Razvan

An SIRS type model of disease transmission in an open environment is discussed. We use the Poincaré index together with a perturbation method to show that the endemic proportions need not be unique.

Stephen C. Milne

In this paper we derive many infinite families of explicit exact formulas involving either squares or triangular numbers, two of which generalize Jacobi&#39;s 4 and 8 squares identities to 4n^2 or 4n(n+1) squares, respectively, without using cusp forms. In fact, we similarly generalize to infinite families all of Jacobi&#39;s explicitly stated degree 2, 4, 6

A. V. Efremov

A short review of problems with parton distribution functions in nucleons, non-polarized and polarized, is given. The main part is devoted to the transversity distribution its possible measurement and its first experimental probe via spin asymmetry in semi-inclusive DIS. It is argued that the proton transversity distribution could be successfully measured in

B. A. Magradze

We analyze two sets of specific functions, that/which form the basis of the nonpower asymptotic expansions both in the timelike and spacelike regions for single scale dependent QCD observables in the Shirkov--Solovtsov&#39;s Analytic Perturbation Theory (APT) free of unphysical singularities. These functions are explicitly derived up to the third order in th

Alessandro Silva, Shimon Levit

In controlled dephasing as a result of the interaction of a controlled environment (dephasor) and the system under observation (dephasee) the states of the two subsystems are entangled. Using as an example the ``Which Path Detector&#39;&#39;, we discuss how the entanglement influences the controlled dephasing. In particular, we calculate the suppression $ν$

A Lamacraft, B D Simons

When subject to a weak magnetic impurity potential, the order parameter and quasi-particle energy gap of a bulk singlet superconductor are suppressed. According to the conventional mean-field theory of Abrikosov and Gor&#39;kov, the integrity of the energy gap is maintained up to a critical concentration of magnetic impurities. In this paper, a field theoret

Srikanth Sastry

The inherent structure approach, wherein thermodynamic and structural changes in glass forming liquids are analyzed in terms of local potential energy minima that the liquid samples, has recently been applied extensively to the study of thermodynamic aspects of glass forming liquids. The evalation of the configurational entropy, which arises from the multipl

Srikanth Sastry, Nivedita Deo, Silvio Franz

We study the statistical properties of eigenvalues of the Hessian matrix ${\cal H}$ (matrix of second derivatives of the potential energy) for a classical atomic liquid, and compare these properties with predictions for random matrix models (RMM). The eigenvalue spectra (the Instantaneous Normal Mode or INM spectra) are evaluated numerically for configuratio

Kazuhiko Kuroki, Masao Ogata, Ryotaro Arita, Hideo Aoki

The competition between spin-triplet and singlet pairings is studied theoretically for the tight-binding $α$-$β$ bands in Sr$_2$RuO$_4$, which arise from two sets of quasi-one dimensional Fermi surfaces. Using multiband FLEX approximation, where we incorporate an anisotropy in the spin fluctuations as suggested from experiments, we show that (i) the triplet

Anatoli Polkovnikov, Subir Sachdev, Matthias Vojta

We present a theory for recent STM studies of Zn impurities in the superconductor BSCCO, using insights from NMR experiments which show that there is a net S=1/2 moment on the Cu ions near the Zn. We argue that the Kondo spin dynamics of this moment is the origin of the low bias peak in the differential conductance, rather than a resonance in a purely potent

C. Alard, J. Blommaert, C. Cesarsky, N. Epchtein

By cross-correlating the results of two recent large-scale surveys, the general properties of a well defined sample of semi-regular variable stars have been determined. ISOGAL mid-infrared photometry and MACHO lightcurves are assembled for approximately 300 stars in the Baade&#39;s Windows of low extinction towards the Galactic bulge. These stars are mainly

M. Sugizaki, K. Mitsuda, H. Kaneda, K. Matsuzaki

The X-ray emission from the central region of the Galactic plane, |l|<45 deg and |b|<0.4 deg, was studied in the 0.7-10 keV energy band with a spatial resolution of ~3&#39; with the ASCA observatory. We developed a new analysis method for the ASCA data to resolve discrete sources from the extended Galactic ridge X-ray emission (GRXE). We resolved 163 discret

G. E. Brown, Mannque Rho

The notion that hadron masses scale according to the scaling of the quark condensate in hadronic matter, partly supported by a number of observations in finite nuclei, can be interpreted in terms of Harada-Yamawaki&#39;s ``vector manifestation&#34; (VM) of chiral symmetry. In this scenario, near chiral restoration, the vector meson masses drop to zero {\it i

Florian Meier, Daniel Loss

We study theoretically the spin dynamics of the ferric wheel, an antiferromagnetic molecular ring. For a single nuclear or impurity spin coupled to one of the electron spins of the ring, we calculate nuclear and electronic spin correlation functions and show that nuclear magnetic resonance (NMR) and electron spin resonance (ESR) techniques can be used to det

Taichi Itoh, Phillial Oh, Cheol Ryou

We consider a hybrid of nonlinear sigma models in which two complex projective spaces are coupled with each other under a duality. We study the large N effective action in 1+1 dimensions. We find that some of the dynamically generated gauge bosons acquire radiatively induced masses which, however, vanish along the self-dual points where the two couplings cha

Norisuke Sakai, Shigemitsu Tomizawa

A solution of Einstein equations is obtained for our four-dimensional world as an intersection of a wall and a string-like defect in seven-dimensional spacetime with a negative cosmological constant. A matter energy-momentum tensor localized on the wall and on the string is needed. A single massless graviton is found and is localized around the intersection.

Stephen R. Kane, Kailash C. Sahu

The spectroscopy of microlensed sources towards the Galactic bulge provides a unique opportunity to study (i) the kinematics of the Galactic bulge, particularly its far-side, (ii) the effects of extinction on the microlensed sources, and (iii) the contributions of the bulge and the disk lenses to the microlensing optical depth. We present the results from su

Wung-Hong Huang

The renormalization of effective potentials for the noncommutative scalar field theory at high temperature are investigated to the two-loop approximation. The Feynman diagrams in evaluating the effective potential may be classified into two types: the planar diagrams and nonplanar diagrams. The nonplanar diagrams, which depend on the parameter of noncommutat

I. Rudychev

We discuss origin of equivalence between noncommutative and ordinary Yang-Mills from point of view of string theory. Working in BRST/Hamiltonian framework first we investigate string model in the decoupling limit and show that change of variables and applying the conversion of constraints of decoupled string theory gives commuting coordinates on the D-brane.

Nicolai Reshetikhin, Milen Yakimov

We derive an explicit expression for the Haar integral on the quantized algebra of regular functions C_q[K] on the compact real form K of an arbitrary simply connected complex simple algebraic group G. This is done in terms of the irreducible *-representations of the Hopf *-algebra C_q[K]. Quantum analogs of the measures on the symplectic leaves of the stand

Shinji Mukohyama

A simple five-dimensional brane world model is proposed, motivated by M-theory compactified on a six-dimensional manifold of small radius and an $S^1/Z_2$ of large radius. We include a leading-order higher curvature correction to the tree-level bulk action since in brane world scenarios the curvature scale in the bulk may be comparable to the five-dimensiona