arXiv papers from December 2000

M. N. Chernodub, F. V. Gubarev, M. I. Polikarpov, V. I. Zakharov

We discuss predictions for the interaction energy of the fundamental monopoles in gluodynamics introduced via the 't Hooft loop. At short distances, the heavy monopole potential is calculable from first principles. At larger distances, we apply the Abelian dominance models. We discuss the measurements which would be crucial to distinguish between various mod

Pawel O. Mazur

I review the black hole uniqueness theorem and the no hair theorems established for physical black hole stationary states by the early 80'. This review presents the original and decisive work of Carter, Robinson, Mazur and Bunting on the problem of no bifurcation and uniqueness of physical black holes. Its original version was written only few years after my

Mary Beth Ruskai, Stanislaw Szarek, Elisabeth Werner

We give a useful new characterization of the set of all completely positive, trace-preserving (i.e., stochastic) maps from 2x2 matrices to 2x2 matrices. These conditions allow one to easily check any trace-preserving map for complete positivity. We also determine explicitly all extreme points of this set, and give a useful parameterization after reduction to

Oleg Zaitsev

We derive analytic expressions for the wavefunctions and energy levels in the semiclassical approximation for perturbed integrable systems. We find that some eigenstates of such systems are substantially different from any of the unperturbed states, which requires some sort of a resonant perturbation theory. We utilize the semiclassical surface of section me

Jerzy Lewandowski, Tomasz Pawlowski

We formulate conditions on the geometry of a non-expanding horizon $\Delta$ which are sufficient for the space-time metric to coincide on $\Delta$ with the Kerr metric. We introduce an invariant which can be used as a measure of how different the geometry of a given non-expanding horizon is from the geometry of the Kerr horizon. Directly, our results concern

J. L. Goity, D. Lehmann, G. Prezeau, J. Saez

A regularization for effective field theory with two propagating heavy particles is constructed. This regularization preserves the low-energy analytic structure, implements a low-energy power counting for the one-loop diagrams, and preserves symmetries respected by dimensional regularization.

Laura Covi, Hang Bae Kim, Jihn E. Kim, Leszek Roszkowski

Supersymmetric extensions of the Standard Model that incorporate the axion solution to the strong CP problem necessarily contain also the axino, the fermionic partner of the axion. In contrast to the neutralino and the gravitino, the axino mass is generically not of the order of the supersymmetry-breaking scale and can be much smaller. The axino is therefore

Jens Erler, Mingxing Luo

The dominant theoretical uncertainties in both, the anomalous magnetic moment of the muon and the value of the electromagnetic coupling at the Z scale arise from their hadronic contributions. Since these will ultimately dominate the experimental errors, we study the correlation between them, as well as with other fundamental parameters. To this end we presen

Dibyendu Das, Abhik Basu, Mustansir Barma, Sriram Ramaswamy

We study the coupled dynamics of the displacement fields in a one dimensional coupled-field model for drifting crystals, first proposed by R.Lahiri and S.Ramaswamy [{\em Phys. Rev. Lett.} {\bf 79}, 1150 (1997)]. We present some exact results for the steady state and the current in the lattice version of the model, for a special subspace in the parameter spac

Alfredo Herrera-Aguilar, Oleg V. Kechkin

We present the explicit formulae which allow to transform the general solution of the 6D Kaluza--Klein theory on a 3--torus into the special solution of the 6D bosonic string theory on a 3--torus as well as into the general solution of the 5D bosonic string theory on a 2--torus. We construct a new family of the extremal solutions of the 3D chiral equation fo

Eric M. Opdam

The Iwahori-Hecke algebra has a ``natural'' trace $\tau$. This trace is the evaluation at the identity element in the usual interpretation of the Iwahori-Hecke algebra as a sub-algebra of the convolution algebra of a p-adic semi-simple group. The Iwahori-Hecke algebra contains an important commutative sub-algebra ${\bf C}[\theta_x]$, that was described and s

K. Szlachanyi

After a summary on module algebra actions of C^*-weak Hopf algebras we outline the proof of a reconstruction theorem stating that every finite index depth 2 inclusion N < M of unital C^*-algebras with finite dimensional centers is isomorphic to the invariant subalgebra inclusion M^A < M with respect to a regular weak Hopf algebra action. The proof uses the l

Jianwei Qiu, Xiaofei Zhang

We introduce operator definitions for virtual photon fragmentation functions, which are needed for reliable calculations of Drell-Yan transverse momentum ($Q_T$) distributions when $Q_T$ is much larger than the invariant mass $Q$. We derive the evolution equations for these fragmentation functions. We calculate the leading order evolution kernels for partons

Eckart Viehweg, Kang Zuo

Consider the moduli functor of canonically polarized complex manifolds with Hilbert polynomial h, and let M_h be the corresponding coarse quasi-projective moduli scheme. We show that M_h is Brody hyperbolic in the following sense: Assume that for some quasi-projective variety U there exists a morphism U --> M_h, quasi-finite over its image, which is induced

Antonina N. Fedorova, Michael G. Zeitlin

We present applications of variational -- wavelet approach to three different models of nonlinear beam motions with underlying collective behaviour: Vlasov-Maxwell-Poisson systems, envelope dynamics, beam-beam model. We have the representation for dynamical variables as a multiresolution (multiscales) expansion via high-localized nonlinear eigenmodes in the

Seongsik Chang, Jens U. Noeckel, Richard K. Chang, A. Douglas Stone

By combining detailed imaging measurements at different tilt angles with simulations of ray emission from prolate deformed lasing micro-droplets, we conclude that the probability density for the lasing modes in a three-dimensional dielectric microcavity must reside in the chaotic region of the ray phase space. In particular, maximum emission from such chaoti

Shiho Kobayashi, Re'em Sari

Gamma-ray bursts are believed to originate from internal shocks which arise in an irregular relativistic wind. The process has been thought to be inefficient, converting only a few percent of the kinetic energy into gamma-rays. We define ultra efficient internal shocks as those in which the fraction of emitted energy is larger than the fraction of energy giv

Cheng-Tsung Hung, Shin Nan Yang, T. -S. H. Lee

The pion-nucleon scattering is investigated by using several three-dimensional reduction schemes of the Bethe-Salpeter equation for a model Lagrangian involving $\pi$, $N$, $\Delta$, $\rho$, and $\sigma$ fields. It is found that all of the resulting meson-exchange models can give similar good descriptions of the $\pi N$ scattering data up to 400 MeV. However

Antonina N. Fedorova, Michael G. Zeitlin

We present the application of variational-wavelet analysis to numerical/analytical calculations of Wigner functions in (nonlinear) quasiclassical beam dynamics problems. (Naive) deformation quantization and multiresolution representations are the key points.

Vladimir Kazakov, Ivan Kostov, David Kutasov

We construct and study a matrix model that describes two dimensional string theory in the Euclidean black hole background. A conjecture of V. Fateev, A. and Al. Zamolodchikov, relating the black hole background to condensation of vortices (winding modes around Euclidean time) plays an important role in the construction. We use the matrix model to study quant

Amruta Mishra, P. K. Panda, W. Greiner

We derive the equation of state (EOS) for electrically charge neutral dense matter using Quantum Hadrodynamics (QHD) model. This is carried out in a nonperturbative manner including quantum corrections for baryons through a realignment of vacuum with baryon-antibaryon condensates. This yields the results of relativistic Hartree approximation of summing over

Andrei Khrennikov

We start to develop the quantization formalism in a hyperbolic Hilbert space. Generalizing Born's probability interpretation, we found that unitary transformations in such a Hilbert space represent a new class of transformations of probabilities which describe a kind of {\it hyperbolic interference}. The most interesting problem which was generated by our in

V. L. Kalashnikov, E. Sorokin, I. T. Sorokina

A number of factors that influence spectral position of the femtosecond pulse in a Kerr-lens modelocked Cr:LiSGaF laser have been identified: high-order dispersion, gain saturation, reabsorption from the ground state, and stimulated Raman scattering. Using the one-dimensional numerical model for the simulation of the laser cavity, the relative contributions

Gabor Etesi

In this note we prove a theorem on non-vacuum initial data for general relativity. The result presents a ``rigidity phenomenon'' for the extrinsic curvature, caused by the non-positive scalar curvature. More precisely, we state that in the case of asymptotically flat non-vacuum initial data if the metric has everywhere non-positive scalar curvature then the

V. Dmitrasinovic

We give explicit expressions for the three-quark exchange operators, crossing matrices and Fierz transforms for the SU(2) and SU(3) groups. We identify the invariant terms in these operators and express them in terms of Casimir operators.

V. Dmitrasinovic

Only two-body [${\rm F}_{i} \cdot {\rm F}_{j}$] confining potentials have been considered, thus far, in the quark model without gluons, which by construction can only depend on the quadratic Casimir operator of the colour SU(3) group. A three-quark potential that depends on the cubic Casimir operator is added to the quark model. This results in improved prop

Takeo Kojima

We study the affine $A_{n-1}^{(1)}$ Toda fields with boundary reflection. Our approach is based on the free field approach. We construct free field realizations of the boundary state and its dual. For an application of these realizations, we present integral representations for the form factors of the local operators. In a limiting case $\rho \to \infty$, ou

F. Hautmann

Motivated by asking how to combine parton showers with nonleading QCD matrix elements, we discuss a subtractive technique based on gauge-invariant Wilson-line operators and how this can be used to treat the soft region.

Edmund Bertschinger

These lecture notes discuss several topics in the physics of cosmic structure formation starting from the evolution of small-amplitude fluctuations in the radiation-dominated era. The topics include relativistic cosmological perturbation theory with the scalar-vector-tensor decomposition, the evolution of adiabatic and isentropic initial fluctuations, microw

A. Heck

Geographical distributions, ages and sizes of astronomy-related organizations have been investigated from comprehensive and up-to-date samples extracted from the master files for StarGuides/StarWorlds. Results for professional institutions, associations, planetariums, and public observatories are commented, as well as specific distributions for astronomy-rel

Tae-Sun Kim, Stefano Cristiani, Sandro D'Odorico

Using high resolution (R ~ 45000), high S/N (20-50) VLT/UVES observations covering the Lyman-alpha forest at 1.5 < z < 2.4 combined with similar observations at z > 2.4 from the literature, we have presented the redshift evolution of the Lyman-alpha forest at 1.5 < z < 4. We applied two parallel analyses: the tradiational Voigt profile fitting and a statisti

Malgorzata Rowicka-Kudlicka

We consider quantum group theory on the Hilbert space level. We find all unitary representations of three braided quantum groups related to the quantum ``ax+b'' group. First we introduce an auxiliary braided quantum group, which is apparently not related to the quantum ``ax+b'' group, but easy to work with. We find all unitary representations of this quantum

Ken Intriligator, Matt Kleban, Jason Kumar

We argue that type II string theories contain unstable NS4 branes, which descend from a conjectured unstable M4 brane of M-theory. Assuming that an M2 brane can arise in M5 brane/anti-brane annihilation, the unstable M4 brane, and also an unstable M3 brane, must exist as sphalerons. We compare the tensions of the unstable NS4 branes, M4 brane, and related ty

Philip R. Johnson, B. L. Hu

We apply the open systems concept and the influence functional formalism introduced in Paper I to establish a stochastic theory of relativistic moving spinless particles in a quantum scalar field. The stochastic regime resting between the quantum and semi-classical captures the statistical mechanical attributes of the full theory. Applying the particle-centr

D. V. Ahluwalia, M. Kirchbach

A careful ab initio construction of the finite-mass (1/2,1/2) representation space of the Lorentz group reveals it to be a spin-parity multiplet. In general, it does not lend itself to a single-spin interpretation. We find that the (1/2,1/2) representation space for massive particles naturally bifurcates into a triplet and a singlet of opposite relative intr

Roger Ellman

Over the past century a succession of five different independent astronomical phenomena have been discovered, each appearing to be the result of a common underlying cause that also produces an unaccounted-for acceleration that is: quite small, centrally directed in the system exhibiting each phenomenon, non-gravitational, distance independent, and apparently

M. Bawin, S. A. Coon

In this contribution we study the Dirac equation for a finite size proton in an external electric field with explicit introduction of Dirac-Pauli form factors. Our aim is twofold. On the one hand, we wish to study whether our conclusions regarding the exact cancellation between Dirac form factor and Foldy term contributions occurring for the neutron still ho

K. R. S. Balaji, A. Pérez-Lorenzana, A. Yu. Smirnov

We assume that the mass matrix of active neutrinos has hierarchical form with small mixings, similar to quark mass matrix. We show that the large mixings between $\nu_\mu$ and $\nu_\tau$ as well as between $\nu_e$ and certain combination of $\nu_\mu$ and $\nu_\tau$ required by the present data can appear due to the presence of a sterile neutrino state. Two r

Sidney A. Coon

The group theoretical analysis of the Coleman-Glashow tadpole picture of "meson-mixing" is quantitatively reproduced by the u-d constituent quark mass difference in quantum loop calculations of the self-energies of mesons. This demonstration that the Coleman-Glashow scales can be directly calculated from the constituent $u - d$ quark mass difference finishes

S. A. Coon, H. K. Han

We introduce new values of the strength constants (i.e., $a$, $b$, $c$, and $d$ coefficients) of the Tucson-Melbourne (TM) 2$\pi$ exchange three nucleon potential. The new values come from contemporary dispersion relation analyses of meson factory $\pi$N scattering data. We make variational Monte Carlo calculations of the triton with the original and updated

C. N. Ferreira, M. B. D. S. M. Porto, J. A. Helayel-Neto

We study a cosmic string solution of an N=1-supersymmetric version of the Cremmer-Scherk-Kalb-Ramond (CSKR) Lagrangian coupled to a vector superfield by means of a topological mass term. The 2-form gauge potential is proposed to couple non-minimally to matter, here described by a chiral scalar superfield. The important outcome is that supersymmetry is kept e

M. T. Pena, S. A. Coon, J. Adam, A. Stadler

We adapt the off-shell $\pi$N amplitude of the Tucson-Melbourne three-body force to the half-off-shell amplitude of the pion rescattering contribution to $pp \to pp \pi^0$ near threshold. This {\em pion} rescattering contribution, together with the impulse term, provides a good description of the data when the half-off-shell amplitude is linked to the phenom

Roberto Frezzotti, Pietro Antonio Grassi, Stefan Sint, Peter Weisz

Lattice QCD with Wilson quarks and a chirally twisted mass term represents a promising alternative regularization of QCD, which does not suffer from unphysical fermion zero modes. We show how the correlation functions of the renormalized theory are related to the theory with a standard parameterization of the mass term. In particular we discuss the condition

Akira Oguri

We study effects of electron correlation on the transport through a small interacting system connected to reservoirs using an effective Hamiltonian which describes the free quasi-particles of a Fermi liquid. The effective Hamiltonian is defined microscopically with the value of the self-energy at $\omega=0$. Specifically, we apply the method to a Hubbard cha

V. R. Gavrilov, V. N. Melnikov

D-dimensional cosmological model describing the evolution of a perfect fluid with negative pressure (x-fluid) and a fluid possessing both shear and bulk viscosity in n Ricci-flat spaces is investigated. The second equations of state are chosen in some special form of metric dependence of the shear and bulk viscosity coefficients. The equations of motion are

Khaled Saaidi, Mohammad Khorrami

A generalization of the two-dimensional Yang-Mills and generalized Yang-Mills theory is introduced in which the building B-F theory is nonlocal in the auxiliary field. The classical and quantum properties of this nonlocal generalization are investigated and it is shown that for large gauge groups, there exist a simple correspondence between the properties a

Arshad Momen, G. Dastegir Al-Quaderi

We compute the quark-antiquark potential employing the continuum action for QCD-like random lattice strings proposed by Siegel. The model leads to a potential similar to those obtained from Nambu-Goto string theory but has some modifications which we interpret as velocity dependent contributions. We also propose to add extra terms in the action which lead to

I. A. Lubashevsky, V. V. Gafiychuk, A. V. Priezzhev

Previously we have developed a free boundary model for local thermal coagulation induced by laser light absorption when the tissue region affected directly by laser light is sufficiently small and heat diffusion into the surrounding tissue governs the necrosis growth. In the present paper surveying the obtained results we state the point of view on the necro

Victor Berezin

Everybody knows what the classical black holes are. In short, this is a spacetime region beyond the so-called event horizon. The notion of the event horizon is mathematically well defined. The situation with a definition of quantum black hole is not so clear. The problem is that the classical event horizon can be defined only globally, i.e. in order to be su

Youngung Lee, A. A. Stark, H. G. Kim, D. Moon

A survey is presented of the Galactic plane in the J=1-0 transition of (13)CO. About 73,000 spectra were obtained with the 7 m telescope at Bell Laboratories over a ten-year period. The coverage of survey is (l, b) = (-5 to 117, -1 to +1), or 244 square degrees, with a grid spacing of 3' for |b| < 0.5, and a grid spacing of 6' for |b| > 0.5. The data present

Nicolau C. Saldanha

Kasteleyn counted the number of domino tilings of a rectangle by considering a mutation of the adjacency matrix: a Kasteleyn matrix K. In this paper we present a generalization of Kasteleyn matrices and a combinatorial interpretation for the coefficients of the characteristic polynomial of KK^\ast (which we call the singular polynomial), where K is a general

W. van Driel, Y. Gao, D. Monnier-Ragaigne

A total of 19 luminous infrared galaxy mergers, with L_IR~2 10^11 L_sun for H_0=75 km/s/Mpc, have been observed in the HI line at Nancay and four of them were observed at Arecibo as well. Of these 19, ten had not been observed before. Six were clearly detected, one of which for the first time. The objective was to statistically sample the \HI gas mass in lum

K. Sznajd-Weron, R. Weron

A simple Ising spin model which can describe the mechanism of price formation in financial markets is proposed. In contrast to other agent-based models, the influence does not flow inward from the surrounding neighbors to the center site, but spreads outward from the center to the neighbors. The model thus describes the spread of opinions among traders. It i

V. S. Fadin

Representation of non-forward scattering amplitudes in the BFKL approach is discussed and the results obtained in the next-to leading order are briefly reviewed.

St. Hobai, Zita Fazakas

Effective surfactant:phospholipid ratios (i.e. molar ratios in the mixed aggregates, vesicles or micelles) have been determined by static light-scattering for the interaction of egg-yolk lecithin (EYL) multilamellar vesicles (MLV) with Triton X-100 (TX-100), sodium deoxycholate (DOCNa) and cetyltrimethylammonium bromide (CTMB). The suspension of MLV-EYL was

E. G. Vorontsova, G. S. Sharov

In $D$-dimensional dilaton gravitational model stationary Schwarzschild type solutions (centrally symmetrical solutions in vacuum) are obtained. They contain the two-parameter set of solutions: the first parameter is proportional to a central mass and the second one describes intensity of the dilaton field. If the latter parameter equals zero we have pure Sc

Shin'ichi Nojiri, Octavio Obregon, Sergei D. Odintsov, Vladimir I. Tkach

AdS/CFT induced quantum dilatonic brane-world where 4d boundary is flat or de Sitter (inflationary) or Anti-de Sitter brane is considered. The classical brane tension is fixed but boundary QFT produces the effective brane tension via the account of corresponding conformal anomaly induced effective action. This results in inducing of brane-worlds in accordanc

Chao-Shang Huang, Tianjun Li, Liao Wei, Qi-Shu Yan

It is shown that the new sources of CP violation can be generated in the models with more than one extra dimensions. In the supersymmetric models on the space-time $M^4\times T^2/Z_2$, where the radius moduli have auxiliary vacuum expectation values and the supersymmetry breaking is mediated by the Kaluza-Klein states of gauge supermultiplets, we analyze the

D. L. Wiltshire

This is an introductory set of lecture notes on quantum cosmology, given in 1995 to an audience with interests ranging from astronomy to particle physics. Topics covered: 1. Introduction: 1.1 Quantum cosmology and quantum gravity; 1.2 A brief history of quantum cosmology. 2. Hamiltonian formulation of general relativity: 2.1 The 3+1 decomposition; 2.2 The ac

Takao Suyama

We investigate an action which resembles the effective action of brane-antibrane system derived from boundary string field theory. We find that the action has smooth vortex solutions which saturate the Bogomol'nyi bound.

Z. Guralnik, S. Ramgoolam

We consider the polarization of unstable type IIB D0-branes in the presence of a background five-form field strength. This phenomenon is studied from the point of view of the leading terms in the non-abelian Born Infeld action of the unstable D0-branes. The equations have SO(4) invariant solutions describing a non-commutative 3-sphere, which becomes a classi

Heui-Seol Roh

This study toward quantum gravity (QG) introduces an SU(N) gauge theory with the \Theta vacuum term for gravitational interactions, which leads to a group SU(2)_L x U(1)_Y x SU(3)_C for weak and strong interactions through dynamical spontaneous symmetry breaking (DSSB). Newton gravitation constant G_N and the effective cosmological constant are realized as t

Heui-Seol Roh

Quantum weakdynamics (QWD) as an SU(3)_I gauge theory with the Theta vacuum term is considered to be the unification of the electroweak interaction as an SU(2)_L x U(1)_Y gauge theory. The grand unification of SU(3)_I x SU(3)_C beyond the standard model SU(3)_C x SU(2)_L x U(1)_Y is established by the group SU(3)_I. The grand unified interactions break down

Heui-Seol Roh

This study toward quantum gravity (QG) introduces an SU(N) gauge theory with the \Theta vacuum term as a trial theory. Newton gravitation constant G_N is realized as the effective coupling constant for a massive graviton, G_N /\sqrt{2} = g_f g_g^2/8 M_G^2 \simeq 10^{-38} GeV^{-2} with the gauge boson mass M_G = M_{Pl} \simeq 10^{19} GeV, the gravitational co

Heui-Seol Roh

It is illustrated that quantum nucleardynamics (QND) as an SU(2)_N x U(1)_Z gauge theory, which is generated from quantum chromodynamics (QCD) as an SU(3)_C gauge theory through dynamical spontaneous symmetry breaking, successfully describes nuclear phenomena at low energies. The proton and neutron assigned as a strong isospin doublet are identified as a col

Andreas Hanke, Mehran Kardar

Correlation functions are sensitive to the presence of a boundary. Surface modulations give rise to modified near surface correlations, which can be measured by scattering probes. To determine these correlations, we develop a perturbative calculation in deformations in height from a flat surface. The results, combined with a renormalization group around four

G. Poghosyan, H. Grigorian, D. Blaschke

We study the evolution of the rotation frequency for accreting compact stars. The discontinuous change of the moment of inertia of a rapidly rotating star due to the possible quark core appearance entails a characteristic change in the spin evolution. Numerical solutions have been performed using a model equation of state describing the deconfinement phase t

Jinqiao Duan, Bjorn Schmalfuss

The three-dimensional baroclinic quasigeostrophic flow model has been widely used to study basic mechanisms in oceanic flows and climate dynamics. In this paper, we consider this flow model under random wind forcing and time-periodic fluctuations on fluid boundary (the interface between the oceans and the atmosphere). The time-periodic fluctuations are due t

A. M. M. Pruisken, M. A. Baranov, M. Voropaev

We revisit the $θ$ dependence in $CP^{N-1}$ model with large $N$. We study the consequences of a recently discovered new ingredient of the instanton vacuum, i.e. the massless chiral edge excitations. Contrary to the previous believes, our results demonstrate that the large $N$ expansion displays all the fundamental features of the quantum Hall effect. This i

A. Lazarian

Observations of cosmic microwave background in the range 10-90 GHz have revealed an anomalous foreground component well correlated with 12 \mum, 60 \mum and 100 \mum emission from interstellar dust. As the recent cross-correlation analysis of WHAM Hαmaps with the Tenerife 10 and 15 GHz maps supports an earlier conclusion that the emission does not arise from

Naoki Sasakura

We study low-energy propagation modes on string network lattice. Specifically, we consider an infinite two-dimensional regular hexagonal string network and analyze the low frequency propagation modes on it. The fluctuation modes tangent to the two-dimensional plane respect the spatial rotational symmetry on the plane, and are described by Maxwell theory. The

J. E. Hirsch

The theory of hole superconductivity proposes that the fundamental asymmetry between electrons and holes in solids is responsible for superconductivity. Here we point out a remarkable consequence of this theory: a tendency for negative charge to be expelled from the bulk of the superconductor towards the surface. Experimentally observable consequences of thi

Branislav K. Nikolic

The study reports on the first large statistics numerical experiment searching for rare eigenstates of anomalously high amplitudes in three-dimensional diffusive metallic conductors. Only a small fraction of a huge number of investigated eigenfunctions generates the far asymptotic tail of their amplitude distribution function. The relevance of the relationsh

Aníbal Iucci, Kang Li, Carlos M. Naón

We extend a non local and non covariant version of the Thirring model in order to describe a many-body system with spin-flipping interactions By introducing a model with two fermion species we are able to avoid the use of non abelian bosonization which is needed in a previous approach. We obtain a bosonized expression for the partition function, describing t

Adrián R. Lugo

We develop a systematic perturbative expansion and compute the one-loop two-points, three-points and four-points correlation functions in a non-commutative version of the U(N) Wess-Zumino-Witten model in different regimes of the $\theta$-parameter showing in the first case a kind of phase transition around the value $\theta_c = \frac{\sqrt{p^2 + 4 m^2}}{\Lam

D. M. Sedrakian, D. Blaschke, K. M. Shahabasyan, D. N. Voskresensky

The behaviour of the magnetic field inside the superconducting quark matter core of a neutron star is investigated in the framework of the Ginzburg-Landau theory. We take into account the simultaneous coupling of the diquark condensate field to the usual magnetic and to the gluomagnetic gauge fields. We solve the problem for three different physical situatio

Danilo Behnke, David Blaschke, Victor Pervushin, Denis Proskurin

We define the cosmological parameters $H_{c,0}$, $\Omega_{m,c}$ and $\Omega_{\Lambda, c}$ within the Conformal Cosmology as obtained by the homogeneous approximation to the conformal-invariant generalization of Einstein's General Relativity theory. We present the definitions of the age of the universe and of the luminosity distance in the context of this app

P. Amsterdamski, T. Bulik, D. Gondek-Rosinska, W. Kluzniak

We show that in the limit of low masses (M<0.1M solar), the orbital and rotational frequencies in exact relativistic numerical models of rotating, axially symmetric, quark stars coincide with those for Maclaurin spheroids. In particular, when the eccentricity of the spheroid exceeds a critical value (e>0.83458318), circular orbits in the equatorial plane are

Dariusz Prorok, Ludwik Turko

We consider the $J/\Psi$ suppression at a high energy heavy ion collision. An ideal gas of massive hadrons in thermal and chemical equilibrium is formed in the central region. The finite-size gas expands longitudinally in accordance with Bjorken law. The transverse expansion in a form of the rarefaction wave is taken into account. We show that $J/\Psi$ suppr

Alan Kostelecky, Agnes Roberts

Analogue models for CP violation in neutral-meson systems are studied in a general framework. No-go results are obtained for models in classical mechanics that are nondissipative or that involve one-dimensional oscillators. A complete emulation is shown to be possible for a two-dimensional oscillator with rheonomic constraints, and an explicit example with s

L. G. Althaus, A. M. Serenelli, O. G. Benvenuto

We investigate the effects of element diffusion on the structure and evolution of low-mass helium white dwarfs (WD). Attention is focused on the occurrence of hydrogen shell flashes induced by diffusion processes during cooling phases. Initial models from 0.406 to 0.161 solar masses are constructed by applying mass loss rates at different stages of the RGB e

Ting Lei, Raymond J. Hawkins

We compare observed corporate cumulative default probabilities to those calculated using a stochastic model based on an extension of the work of Black and Cox and find that corporations default as if via diffusive dynamics. The model, based on a contingent-claims analysis of corporate capital structure, is easily calibrated with readily available historical

Grigori Litvinov, Victor Maslov, Grigori Shpiz

In this paper, we present an algebraic approach to idempotent functional analysis, which is an abstract version of idempotent analysis. The basic concepts and results are expressed in purely algebraic terms. We consider idempotent versions of certain basic results of linear functional analysis, including the theorem on the general form of a linear functional

S. N. Dolya, O. B. Zaslavskii

We present the general form of potentials with two given energy levels $E_{1}$, $E_{2}$ and find corresponding wave functions. These entities are expressed in terms of one function $\xi (x)$ and one parameter $\Delta E=E_{2}$-$E_{1}$. We show how the quantum numbers of both levels depend on properties of the function $\xi (x)$. Our approach does not need res

I. Akushevich, E. Kuraev, B. Shaikhatdenov

For the kinematical region when a hard photon is emitted predominantly close to the direction of motion of a longitudinally polarized initial electron and relatively small momentum transfer to a proton we calculate the azimuthal asymmetry of photon emission. It arises from the interference of the Bethe-Heitler amplitude and those which are described by a hea

Guillermo A. Silva

In the thesis we analize different problems related to the supersymmetric extension of the Dirac-Born-Infeld action. In chapter 2 we introduce the DBI action and show how it appears in string theory, we discuss also it's connection with Dp-branes. Chapter 3 is a self contained introduction to supersymmetry, with emphasis on BPS states. In chapter 4 we constr

Guillermo Torres

Eclipses in the 14.4-day period double-lined binary SS Lac were observed photographically and visually early in the 20th century, but stopped some 50 or 60 years ago. This has been explained by the presence of a distant third star in the system, which has now been detected spectroscopically with a period of 679 days. The plane of the orbit of the binary is c

Jiangbin Gong, Paul Brumer

Extensive coherent control over quantum chaotic diffusion using the kicked rotor model is demonstrated and its origin in deviations from random matrix theory is identified. Further, the extent of control in the presence of external decoherence is established. The results are relevant to both areas of quantum chaos and coherent control.

Howard Georgi, Aaron K. Grant, Girma Hailu

We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running

Tony Gherghetta, Alex Pomarol

We study the breaking of supersymmetry in five-dimensional (5d) warped spaces, using the Randall-Sundrum model as a prototype. In particular, we present a supersymmetry-breaking mechanism which has a geometrical origin, and consists of imposing different boundary conditions between the fermions and bosons living in the 5d bulk. The scale of supersymmetry bre

Daniel M. Sforza

Finite dimensional models that mimic the constraint structure of Einstein's General Relativity are quantized in the framework of BRST and Dirac's canonical formalisms. The first system to be studied is one featuring a constraint quadratic in the momenta (the "super-Hamiltonian") and a set of constraints linear in the momenta (the "supermomentum" constraints)

G. S. Lozano, E. F. Moreno, F. A. Schaposnik

We construct exact soliton solutions to the Chern-Simons-Higgs system in noncommutative space, for non-relativistic and relativistic models. In both cases we find regular vortex-like solutions to the BPS equations which approach the ordinary selfdual non-topological and topological solitons when the noncommutative parameter $\theta$ goes to zero.

S. V. Buldyrev, S. Havlin, A. Ya. Kazakov, M. G. E. da Luz

We consider a Levy flyer of order alpha that starts from a point x0 on an interval [O,L] with absorbing boundaries. We find a closed-form expression for the average number of flights the flyer takes and the total length of the flights it travels before it is absorbed. These two quantities are equivalent to the mean first passage times for Levy flights and Le

Nils Berglund, Barbara Gentz

Additive white noise may significantly increase the response of bistable systems to a periodic driving signal. We consider two classes of double-well potentials, symmetric and asymmetric, modulated periodically in time with period $1/\eps$, where $\eps$ is a moderately (not exponentially) small parameter. We show that the response of the system changes drast

Sascha Husa, Manuela Campanelli, Roberto Gomez, Jeffrey Winicour

We present a characteristic algorithm for computing the perturbations of a Schwarzschild spacetime by means of solving the Teukolsky equations. Our methods and results are expected to have direct bearing on the study of binary black holes presently underway using a fully {\em nonlinear} characteristic code \cite{Gomez98a}.

K. Doerr, K. -H. Mueller, T. Walter, M. Sahana

We report on the non-linear in-plane electrical transport in coherently grown [La0.7Sr0.3MnO3/SrTiO3] multilayers with ultrathin (< 3 nm) single layers. Current-induced switching of the conductance, with low conductance at larger currents, is demonstrated. The conductance switching is modified under a magnetic field, resulting in an extremely large magnetore

Sergei G. Sharapov, Hans Beck, Vadim M. Loktev

We derive finite temperature time-dependent effective actions for the phase of the pairing field, which are appropriate for a 2D electron system with both non-retarded d- and s-wave attraction. As for s-wave pairing the d-wave effective action contains terms with Landau damping, but their structure appears to be different from the s-wave case due to the fact

J. K. Webb, M. T. Murphy, V. V. Flambaum, V. A. Dzuba

We describe the results of a search for time variability of the fine structure constant, alpha, using absorption systems in the spectra of distant quasars. Three large optical datasets and two 21cm/mm absorption systems provide four independent samples, spanning 23% to 87% of the age of the universe. Each sample yields a smaller alpha in the past and the opt

Prot Pakonski, Jakub Zakrzewski

Dynamics of hydrogen atom driven by microwave field of arbitrary polarization is approximated by the discrete mapping. The map describes the change of dynamical variables from an aphelion or a perihelion to the next one. The results are compared with numerical simulation and previous approximations.

A. A. Ivanov, D. V. Pasechnik, S. V. Shpectorov

The Baby Monster group B acts naturally on a geometry E(B) with diagram c.F_4(t) for t=4 and the action of B on E(B) is flag-transitive. It possesses the following properties: (a) any two elements of type 1 are incident to at most one common element of type 2, and (b) three elements of type 1 are pairwise incident to common elements of type 2 iff they are in