June 2000 arXiv papers — page 19

R. Amorim, J. Barcelos-Neto, C. Wotzasek

We consider the quantum mechanical analog of the nonlinear sigma model. There are difficulties to completely embed this theory by directly using the Batalin, Fradkin, Fradkina, and Tyutin (BFFT) formalism. We show in this paper how the BFFT method can be conveniently adapted in order to achieve a gauge theory that partially embeds the model.

Ramzi R. Khuri

We make some observations regarding string/black hole correspondence with a view to understanding the nature of the quantum degrees of freedom of a black hole in string theory. In particular, we compare entropy change in analogous string and black hole processes in order to support the interpretation of the area law entropy as arising from stringy constituen

K. Golec-Biernat

We present a description of inclusive and diffractive structure functions in DIS at small $x$, using a model based on high energy factorization. In this model the two processes have physical interpretation in terms of the virtual photon wave function and the dipole cross section. We postulate the dipole cross section form in a way in which unitarity is taken

I. Akushevich, D. Ryckbosch, N. Shumeiko, A. Tolkachev

The contribution of the radiative tail from the quasielastic peak to low order radiative correction to deep inelastic scattering of polarized leptons by polarized $^3$He was calculated within the sum rules formalism and $y$-scaling hypothesis. Numerical analysis was carried out under the conditions of HERMES experiment.

Michael Melles

The infrared structure of spontaneously broken gauge theories is phenomenologically very important and theoretically a challenging problem. Various attempts have been made to calculate the higher order behavior of large double-logarithmic (DL) corrections originating from the exchange of electroweak gauge bosons resulting in contradictory claims. We present

A. Metz, H. G. Dosch, A. Hebecker, H. J. Pirner

The semiclassical approach to small-x physics is briefly reviewed, where the main emphasis is on the determination of the gluon distribution at NLO.

I. M. Suslov

High orders of perturbation theory can be calculated by the Lipatov method, whereby they are determined by saddle-point configurations (instantons) of the corresponding functional integrals. For most field theories, the Lipatov asymptotics has the functional form c a^N Γ(N+b) (N is the order of perturbation theory), and the relative corrections to it have a

Stefan Groote

We give an overview over recent calculations of baryonic correlator functions with finite mass quarks in view on their applicability for QCD sum rules. The QCD sum rule method is then demonstrated within the Heavy Quark Effective Theory.

T. Struckmann, K. Schilling, P. Ueberholz, N. Eicker

We present a study on the direct determination of the $η'$ mass on the full set of SESAM and T$χ$L QCD vacuum configurations with 2 active flavours of Wilson fermions, at $β= 5.6$. We observe a definite dependency of the two-loop correlator on the topological charge sector.

Tom Martin

Two complementary and equally important approaches to relativistic physics are explained. One is the standard approach, and the other is based on a study of the flows of an underlying physical substratum. Previous results concerning the substratum flow approach are reviewed, expanded, and more closely related to the formalism of General Relativity. An absolu

Neil J. Gunther

Many scientific applications use the X11 window environment; an open source windows GUI standard employing a client/server architecture. X11 promotes: distributed computing, thin-client functionality, cheap desktop displays, compatibility with heterogeneous servers, remote services and administration, and greater maturity than newer web technologies. This pa

Neil J. Gunther

Traditional UNIX time-share schedulers attempt to be fair to all users by employing a round-robin style algorithm for allocating CPU time. Unfortunately, a loophole exists whereby the scheduler can be biased in favor of a greedy user running many short CPU-time processes. This loophole is not a defect but an intrinsic property of the round-robin scheduler th

B. Noheda, D. E. Cox, G. Shirane, R. Guo

Recent structural studies of ferroelectric PbZr(1-x)TixO3 (PZT) with x= 0.48, have revealed a new monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper, the stability region of all three phases has bee

H. Won, K. Maki

Until recently it has been believed that the superconductivity in Sr$_2$RuO$_4$ is described by p-wave pairing. However, both the recent specific heat and the magnetic penetration depth measurements on the purest single crystals of Sr$_2$RuO$_4$ appear to be explained more consistently in terms of f-wave superconductivity. In order to further this hypothesis

Benoit des Ligneris Marcel Aubin Julian Cave

The method consists in the monitoring of the temperature variation of a superconductor tape subjected to a trapezoidal current pulse. Simulations of the experiment were performed using the lumped capacitance model and also the finite element method. The former reproduces the sample's reaction for the increasing and decreasing parts of the pulse. The same

Michael N. Leuenberger, Daniel Loss

Reply to the comment of E.M. Chudnovsky and D.A. Garanin on Europhys. Lett. 46, 692 (1999).

Arjendu K. Pattanayak, Arnaldo Gammal, Charles A. Sackett, Randall G. Hulet

Bose-Einstein condensates of $^7$Li have been limited in number due to attractive interatomic interactions. Beyond this number, the condensate undergoes collective collapse. We study theoretically the effect of driving low-lying collective modes of the condensate by a weak asymmetric sinusoidally time-dependent field. We find that driving the radial breathin

M. Sellitto, J. J. Arenzon

We show that the main dynamical features of granular media can be understood by means of simple models of fragile-glass forming liquid provided that gravity alone is taken into account. In such lattice-gas models of cohesionless and frictionless particles, the compaction and segregation phenomena appear as purely non-equilibrium effects unrelated to the Bolt

Zhi-Feng Huang

Based on the minute-by-minute data of the Hang Seng Index in Hong Kong and the analysis of probability distribution and autocorrelations, we find that the index fluctuations for the first few minutes of daily opening show behaviors very different from those of the other times. In particular, the properties of tail distribution, which will show the power law

J. Flores, M. Horoi, M. Mueller, T. H. Seligman

Using longer spectra we re-analyze spectral properties of the two-body random ensemble studied thirty years ago. At the center of the spectra the old results are largely confirmed, and we show that the non-ergodicity is essentially due to the variance of the lowest moments of the spectra. The longer spectra allow to test and reach the limits of validity of F

S. Martinez, F. Pennini, A. Plastino

We revisit some topics of classical thermostatistics from the perspective of the nonextensive optimal Lagrange multipliers (OLM), a recently introduced technique for dealing with the maximization of Tsallis' information measure. It is shown that Equipartition and Virial theorems can be reproduced by Tsallis' nonextensive formalism independently of th

Nadya Mason, Aharon Kapitulnik

We present results on disordered amorphous films which are expected to undergo a field-tuned Superconductor-Insulator Transition. Based on low-field data and I-V characteristics, we find evidence of a low temperature Metal-to-Superconductor transition. This transition is characterized by hysteretic magnetoresistance and discontinuities in the I-V curves. The

J. Neuefeind

The partial structure factors (PSF) of molten ZnCl2 are known since 1981 due to the neutron diffraction experiments by Biggin and Enderby. It is shown in this article that the set of PSF derived from this experiment is not consistent with new XRD data with much better statistical accuracy. A new set of PSF is derived which corrects this deficiency. The first

S. E. Skipetrov, R. Maynard

We develop a self-consistent theory of temporal fluctuations of a speckle pattern resulting from the multiple scattering of a coherent wave in a weakly nonlinear disordered medium. The speckle pattern is shown to become unstable if the nonlinearity exceeds a threshold value. The instability is due to a feedback provided by the multiple scattering and manifes

R. Bonifacio, B. W. J. McNeil, N. Piovella, G. R. M. Robb

A semi-classical theory of coherent light scattering from an elongated sample of cold atoms exposed to an off-resonant laser beam is presented. The model, which is a direct extension of that of the collective atomic recoil laser (CARL), describes the emission of two superradiant pulses along the sample's major axis simultaneous with the formation of a bi

Ph. Ebert, K. Urban, L. Aballe, C. H. Chen

The atomic and electronic structure of positively charged P vacancies on InP(110) surfaces is determined by combining scanning tunneling microscopy, photoelectron spectroscopy, and density-functional theory calculations. The vacancy exhibits a nonsymmetric rebonded atomic configuration with a charge transfer level 0.75+-0.1 eV above the valence band maximum.

Jiri Hoogland, Dimitri Neumann

In this article we present new results for the pricing of arithmetic Asian options within a Black-Scholes context. To derive these results we make extensive use of the local scale invariance that exists in the theory of contingent claim pricing. This allows us to derive, in a natural way, a simple PDE for the price of arithmetic Asians options. In the case o

G. Alber

A renormalization group method is developed with which thermodynamic properties of a weakly interacting, confined Bose gas can be investigated. Thereby effects originating from a confining potential are taken into account by periodic boundary conditions and by treating the resulting discrete energy levels of the confined degrees of freedom properly. The resu

Hans-Karl Janssen

A model of directed percolation processes with colors and flavors that is equivalent to a population model with many species near their extinction thresholds is presented. We use renormalized field theory and demonstrate that all renormalizations needed for the calculation of the universal scaling behavior near the multicritical point can be gained from the

Ramin Golestanian, Tanniemola B. Liverpool

The statistical mechanics of a ribbon polymer made up of two semiflexible chains is studied using both analytical techniques and simulation. The system is found to have a crossover transition at some finite temperature, from a type of short range order to a fundamentally different sort of short range order. In the high temperature regime, the 2-point correla

T. Winiecki, C. S. Adams

We simulate the motion of a massive object through a dilute Bose-Einstein condensate by numerical solution of the non-linear Schrödinger equation coupled to an equation of motion for the object. Under a constant applied force, the object accelerates up to a maximum velocity where a vortex ring is formed which slows the object down. If the applied force is le

J. Neuefeind

Hard electromagnetic radiation diffraction experiments on copper(I)-bromide melt are presented. Combining the result of this experiment with earlier neutron diffraction experiments the partial pair distribution functions of CuBr have been determined. The differing results for two of these functions obtained recently by various techniques are discussed. A pot

T. S. Lo, S. W. Lim, P. M. Hui, N. F. Johnson

We present detailed numerical results for a modified form of the so-called Minority Game, which provides a simplified model of a competitive market. Each agent has a limited set of strategies, and competes to be in a minority. An evolutionary rule for strategy modification is included to mimic simple learning. The results can be understood by considering cro

Lei Liu, C. S. Jayanthi, H. Guo, S. Y. Wu

We have shown how the interplay between the broken symmetry associated with the finite single-wall nanotubes (SWNT) and the boundary conditions affects the electronic properties of SWNTs in a profound way. For finite SWNTs (p,q) characterized by p=k+l,q=k-l,p-q=2l,l=0,1...,k, and k=1,2..., we found that the band gaps of finite SWNTs belonging to a certain k

Robert S. Maier, D. L. Stein

We study the pattern of activated trajectories in a double well system without detailed balance, in the weak noise limit. The pattern may contain cusps and other singular features, which are similar to the caustics of geometrical optics. Their presence is reflected in the quasipotential of the system, much as phase transitions are reflected in the free energ

Kyungsik Kim, Y. S. Kong

The scaling behavior of the mutifractality for the sea-bottom topography of the South Sea in Korea is numerically investigated. In particular, we focus on the behavior of the $q$th-moment depth-depth correlation function of the sea-bottom topography and its multifractal spectrum. Through the multifractal analysis, the fractal dimension and the scaling expone

Marc Verheijen, Neil Trentham, Brent Tully, Martin Zwaan

A deep blind HI survey of the nearby spiral rich Ursa Major cluster has been performed with the VLA in parallel with a wide-field R-band imaging campaign of most VLA fields with the CFHT. The goal is to measure the slope of the HI mass function down to HI masses of 10^7 Msun as well as the slope of the faint-end of the luminosity function down to M(R)=-10. T

Renee C. Kraan-Korteweg

Dust and stars in the Milky Way create a ``Zone of Avoidance'' (ZOA) in the distribution of optically visible galaxies of about 25% of the sky. To reduce this gap, optical searches for partially obscured galaxies have been performed. The status of these deep searches, in particular their completeness as a function of foreground extinction are discuss

A. P. Fairall, Renee C. Kraan-Korteweg

An optical search of the Scorpius region - close to the Galactic bulge - has revealed some 1400 partially-obscured galaxies. Redshifts have been obtained for nearly a hundred of these objects. Preliminary indications of large-scale structures are reported.

T. B. Ake, A. K. Dupree, P. R. Young, J. L. Linsky

Far ultraviolet spectra were obtained of the active cool star AB Doradus (HD 36705) during the calibration and checkout period of the FUSE satellite. Observations in this early phase of the mission were taken at a resolving power of 12000-15000 (~20-25 km/s) and covered the spectral range 905-1187 A. The integrated spectrum exhibits strong, rotationally broa

C. S. Kochanek, C. R. Keeton, B. A. McLeod

We develop a theory of Einstein rings and demonstrate it using the infrared Einstein ring images of the quasar host galaxies observed in PG1115+080, B1608+656 and B1938+666. The shape of an Einstein ring accurately and independently determines the shape of the lens potential and the shape of the lensed host galaxy. We find that the host galaxies of PG1115+08

S. Andreon, G. Gargiulo, G. Longo, R. Tagliaferri

[Abriged] Astronomical Wide Field Imaging performed with new large format CCD detectors poses data reduction problems of unprecedented scale which are difficult to deal with traditional interactive tools. We present here NExt (Neural Extractor): a new Neural Network (NN) based package capable to detect objects and to perform both deblending and star/galaxy c

Caroline Terquem, John C. B. Papaloizou

We compute the warping of a disc induced by an inclined dipole. We consider a magnetised star surrounded by a thin Keplerian diamagnetic disc with an inner edge that corotates with the star. We suppose the stellar field is a dipole with an axis that is slightly misaligned with the stellar rotation axis. The rotation axes of the disc material orbiting at larg

A. Letessier-Selvon

Since their first observation in 1962, the existence of Ultra High Energy Cosmic Rays (UHECR) remains a mystery in modern astrophysics. Those cosmic rays, with energies well above 50 EeV ($50\times 10^{18}$eV), can hardly be accelerated, even in the most active parts of our universe such as FR-II radio galaxies or AGNs, nor can they travel on distances large

A. Cillis, S. J. Sciutto

The objective of this work is to report on the modifications in air shower development due to muon bremsstrahlung and muonic pair production. In order to do that we have implemented new muon bremsstrahlung and muonic pair production procedures in the AIRES air shower simulation system, and have used it to simulate ultra high energy showers in different condi

Jean-Paul Kneib, Judith G. Cohen, Jens Hjorth

We report the detection of a massive high-redshift cluster of galaxies near the quadruple quasar RX J0911+05, using the LRIS instrument on the Keck-II telescope. The cluster is found to have a mean redshift of <z>=0.7689+/-0.002 and a velocity dispersion of sigma=836{+180-200} km/s, based on redshift measurements for 24 member galaxies. This massive high-red

J. Richard Gott, Michael S. Vogeley, Silviu Podariu, Bharat Ratra

(Abridged) We develop median statistics that provide powerful alternatives to chi-squared likelihood methods and require fewer assumptions about the data. Applying median statistics to Huchra&#39;s compilation of nearly all estimates of the Hubble constant, we find a median value H_0=67 km/s/Mpc. Median statistics assume only that the measurements are indepe

M. Baker, R. Steinke

Starting from a field theory containing classical vortex solutions, we obtain an effective string theory of these vortices as a path integral over the two transverse degrees of freedom of the string. We carry out a semiclassical expansion of this effective theory, and use it to obtain corrections to Regge trajectories due to string fluctuations.

A. J. S. Hamilton

Formulae are presented for the linear growth factor D/a and its logarithmic derivative dlnD/dlna in expanding Friedmann-Robertson-Walker Universes with arbitrary matter and vacuum densities. The formulae permit rapid and stable numerical evaluation. A fortran program is available at http://casa.colorado.edu/~ajsh/growl/ .

V. Delgado, J. M. Gomez Llorente

The time evolution of driven two-level systems in the far off-resonance regime is studied analytically. We obtain a general first-order perturbative expression for the time-dependent density operator which is applicable regardless of the coupling strength value. In the strong field regime, our perturbative expansion remains valid even when the far off-resona

Alessandra Buonanno, Martin Lemoine, Keith A. Olive

We discuss the mechanism of reheating in pre-big bang string cosmology and we calculate the amount of moduli and gravitinos produced gravitationally and in scattering processes of the thermal bath. We find that this abundance always exceeds the limits imposed by big-bang nucleosynthesis, and significant entropy production is required. The exact amount of ent

N. G. de Almeida, P. B. Ramos, R. M. Serra, M. H. Y. Moussa

In this work we propose an approach to deal with radiation field states which incorporates damping effects at zero temperature. By using some well known results on dissipation of a cavity field state, obtained by standard ab-initio methods, it was possible to infer through a phenomenological way the explicit form for the evolution of the state vector for the

The HEGRA Collaboration, F. Aharonian, A. Akhperjanian, J. Barrio

The energy spectrum of the Blazar type galaxy Markarian 501 (Mrk 501) as measured by the High-Energy-Gamma-Ray Astronomy (HEGRA) air Cerenkov telescopes extends beyond 16 TeV and constitutes the most energetic photons observed from an extragalactic object. A fraction of the emitted spectrum is possibly absorbed in interactions with low energy photons of the

Dmitri Novikov, Jens Schmalzing, Viatcheslav F. Mukhanov

We consider a cosmological model with non-Gaussian initial perturbations, which in principle could be generated in non-standard inflationary scenarios with two or more scalar fields. In particular we focus our attention on the model proposed by Linde & Mukhanov (1997) perturbations are quadratic in a Gaussian field. These perturbations, if they exist, have t

A. B. Larionov, W. Cassing, C. Greiner, U. Mosel

We perform a systematic study of in-plane and out-of-plane proton and neutron flow from nucleus-nucleus collisions within the BUU transport approach employing different parameter sets for the mean-field potentials that can be characterized by the nuclear incompressibility and the stiffness of the momentum-dependent potential. We find that a simultaneous desc

Gabriel Catren, Rafael Ferraro

The paper addresses the quantization of minisuperspace cosmological models, with application to the Taub Model. By desparametrizing the model with an extrinsic time, a formalism is developed in order to define a conserved Schrödinger inner product in the space of solutions of the Wheeler-De Witt equation. A quantum version of classical canonical transformati

W. Dür, G. Vidal, J. I. Cirac, N. Linden

We quantify the capability of creating entanglement for a general physical interaction acting on two qubits. We give a procedure for optimizing the generation of entanglement. We also show that a Hamiltonian can create more entanglement if one uses auxiliary systems.

Markus Brede, Ulrich Behn

We investigate a model where idiotypes (characterizing B-lymphocytes and antibodies of an immune system) and anti-idiotypes are represented by complementary bitstrings of a given length d allowing for a number of mismatches (matching rules). In this model, the vertices of the hypercube in dimension d represent the potential repertoire of idiotypes. A random

C. P. Jessop, CLEO Collaboration

We report results of searches for charmless hadronic B meson decays to pseudoscalar(pi^+-,K^+-,Pi^0 or Ks^0)-vector(Rho, K* or Omega) final states. Using 9.7 million BBbar pairs collected with the CLEO detector, we report first observation of B^- --> Pi^-Rho^0, B^0 --> Pi^+-Rho^-+ and B^- --> Pi^-Omega, which are expected to be dominated by hadronic b --> u

A. Freise, G. Heinzel, K. A. Strain, J. Mizuno

Dual recycling is an advanced optical technique to enhance the signal-to-noise ratio of laser interferometric gravitational wave detectors in a limited bandwidth. To optimise the center of this band with respect to Fourier frequencies of expected gravitational wave signals detuned dual recycling has to be implemented. We demonstrated detuned dual recycling o

Gideon Alexander, Iuliana Cohen

The general features of the Moller scattering and its use as an electron polarimeter are described and studied in view of the planned future high energy e^+e^- linear colliders. In particular the study concentrates on the TESLA collider which is envisaged to operate with longitudinal polarised beams at a centre of mass energy of the order of 0.5 TeV with a l

K. Dosen, Z. Petric

Coherence is demonstrated for categories with binary products and sums, but without the terminal and the initial object, and without distribution. This coherence amounts to the existence of a faithful functor from a free category with binary products and sums to the category of relations on finite ordinals. This result is obtained with the help of proof-theo

Yun-Feng Huang, Wan-Li Li, Chuan-Feng Li, Yong-Sheng Zhang

Beyond the no-cloning theorem, the universal symmetric quantum cloning machine was first addressed by Buzek and Hillery. Here, we realized the one-to-two qubits Buzek-Hillery cloning machine with linear optical devices. This method relies on the representation of several qubits by a single photon. We showed that, the fidelities between the two output qubits

Takao Suyama

We construct a model describing BPS brane-systems using low energy effective theory of brane-antibrane system. Both parallel branes and intersecting branes can be treated by this model. After tachyon condensation, the dynamics of fluctuations around such brane-systems is supersymmetric if the degrees of freedom are restricted on the branes. The form of the t

J. P. Ma

In the framework of HQET inclusive decays of b-flavored hadrons can be handled as decays of the free b-quark approximately. We analyse the correction to this approximation for the inclusive decays into a polarized $J/ψ$,the correction is characterized by two matrix elements defined in HQET. For the $J/ψ$ we use NRQCD to parameterize the formation of the $c\b

Sergey A. Cherkis, Anton Kapustin

We study Bogomolny equations on $R^2\times S^1$. Although they do not admit nontrivial finite-energy solutions, we show that there are interesting infinite-energy solutions with Higgs field growing logarithmically at infinity. We call these solutions periodic monopoles. Using Nahm transform, we show that periodic monopoles are in one-to-one correspondence wi

T. Matsuzawa, H. Nakada, K. Ogawa, G. Momoki

The $10^+$ and $27/2^-$ isomers of the $Z>64$, $N=82$ nuclei are investigated in the shell model framework. We derive an extended seniority reduction formula for the relevant $E2$ transition strengths. Based on the extended formula, as well as on the approximate degeneracy among the $0h_{11/2}$, $2s_{1/2}$ and $1d_{3/2}$ orbits, we argue that the $B(E2)$ dat

S. D. Hsu, F. Sannino, M. Schwetz

We investigate the application of &#39;t Hooft&#39;s anomaly matching conditions to gauge theories at finite matter density. We show that the matching conditions constrain the low-energy quasiparticle spectrum associated with possible realizations of global symmetries.

Brian C. Hall

I review certain results in harmonic analysis for systems whose configuration space is a compact Lie group. The results described involve a heat kernel measure, which plays the same role as a Gaussian measure on Euclidean space. The main constructions are group analogs of the Hermite expansion, the Segal-Bargmann transform, and the Taylor expansion. The resu

Peter Hoyer

We consider the use of arbitrary phases in quantum amplitude amplification which is a generalization of quantum searching. We prove that the phase condition in amplitude amplification is given by $\tan(φ/2) = \tan(ϕ/2)(1-2a)$, where $ϕ$ and $ϕ$ are the phases used and where $a$ is the success probability of the given algorithm. Thus the choice of phases depe

Jindong Zhou, Guang Hou, Shenjun Wu, Yongde Zhang

A theoretical scheme for controlled quantum teleportation is presented, using the entanglement property of GHZ state.

Arun K. Pati, Samuel L. Braunstein, Seth Lloyd

A fast quantum search algorithm for continuous variables is presented. The result is the quantum continuous variable analog of Grover&#39;s algorithm originally proposed for qubits. A continuous variable analog of the Hadamard (i.e., Fourier transform) operation is used in conjunction with inversion about the average of quantum states to allow the approximat

F. Green, S. Homer, C. Pollett

For any $q > 1$, let $\MOD_q$ be a quantum gate that determines if the number of 1&#39;s in the input is divisible by $q$. We show that for any $q,t > 1$, $\MOD_q$ is equivalent to $\MOD_t$ (up to constant depth). Based on the case $q=2$, Moore \cite{moore99} has shown that quantum analogs of AC$^{(0)}$, ACC$[q]$, and ACC, denoted QAC$^{(0)}_{wf}$, QACC$[2]$

Vladimir Melezhik, Peter Schmelcher

Using a combination of semiclassical and recently developed wave packet propagation techniques we find the quantum self-ionization process of highly excited ions moving in magnetic fields which has its origin in the energy transfer from the center of mass to the electronic motion. It obeys a time scale by orders of magnitude larger than the corresponding cla

Peter Schmelcher, Thomas Detmer, Lorenz Cederbaum

Excited states of the hydrogen molecule subject to a homogeneous magnetic field are investigated for the parallel configuration in the complete regime of field strengths B=0-100a.u.. Up to seven excitations are studied for gerade as well as ungerade spin singlet states of Sigma symmetry with a high accuracy. The evolution of the potential energy curves for t

Mikhail V. Ivanov, Peter Schmelcher

Fully numerical mesh solutions of 2D quantum equations of Schroedinger and Hartree-Fock type allow us to work with wavefunctions which possess a very flexible geometry. This flexibility is especially important for calculations of atoms and molecules in strong external fields where neither the external field nor the internal interactions can be considered as

Victor G. Bezchastnov, Peter Schmelcher, Lorenz S. Cederbaum

We analyse the bound states of negatively charged ions which were predicted to exist because of the presence of a magnetic field by Avron et al. We confirm that the number of such states is infinite in the approximation of an infinitely heavy nucleus and provide insight into the underlying physical picture by means of a combined adiabatic and perturbation th

Krzysztof Sacha, Bruno Eckhardt

We consider the final stage of multiple ionization of atoms in a strong linearly polarized laser field within a classical model. We propose that non-sequential multiple ionization is dominated by symmetric escape from a highly excited intermediate complex. For a configuration of N electrons with C_Nv symmetry in a plane perpendicular to the electric field we

Gaurav Dar, Mahendra K. Verma, V. Eswaran

The unit of nonlinear interaction in Navier-Stokes and the Magnetohydrodynamic (MHD) equations is a wavenumber triad ({\bf k,p,q}) satisfying ${\bf k+p+q=0}$. The expression for the combined energy transfer from two of these wavenumbers to the third wavenumber is known. In this paper we introduce the idea of an effective energy transfer between a pair of mod

Sudip Sen Gupta, Predhiman K. Kaw

Nonlinear plasma oscillations in an arbitrary mass ratio cold plasma have been studied using 1-D particle-in-cell simulation. In contrast to earlier work for infinitely massive ion plasmas it has been found that the oscillations phase mix away at any amplitude and that the rate at which phase mixing occurs, depends on the mass ratio ($Δ= m_{-}/m_{+}$) and th

J. Andruszkow

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations

C. Y. Chen

It is revealed that distribution functions of practical gases relate to singularities and such singularities can, with molecular motion, spread to the entire region of interest. It is also shown that even common continuous distribution functions involve a similar quasi-discontinuity difficulty.

M. Labiche, N. A. Orr, F. M. Marques, J. C. Angelique

The two-neutron halo nucleus 14Be has been investigated in a kinematically complete measurement of the fragments (12Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross-sections, neutron angular distributions and invariant mass spectra characteristic of a halo were observed and the electromagnetic (EMD) c

Fotis Diakonos, Detlef Pingel, Peter Schmelcher

It is shown that the asymptotic spectra of finite-time Lyapunov exponents of a variety of fully chaotic dynamical systems can be understood in terms of a statistical analysis. Using random matrix theory we derive numerical and in particular analytical results which provide insights into the overall behaviour of the Lyapunov exponents particularly for strange

Detlef Pingel, Peter Schmelcher, Fotis Diakonos, Ofer Biham

A topological approach and understanding to the detection of unstable periodic orbits based on a recently proposed method (PRL 78, 4733 (1997)) is developed. This approach provides a classification of the set of transformations necessary for the finding of the orbits. Applications to the Ikeda and Henon map are performed, allowing a study of the distribution

M. Dolowschiak, Z. Kovacs

We demonstrate that in the thermostatted three-dimensional Lorentz gas the symmetry of the Lyapunov spectrum can be broken by adding to the system an external magnetic field not perpendicular to the electric field. For perpendicular field vectors, there is a Hamiltonian reformulation of the dynamics and the conjugate pairing rule still holds. This indicates

Victor G. Kac, Minoru Wakimoto

We classify integrable irreducible highest weight representations of non-twisted affine Lie superalgebras. We give a free field construction in the level~1 case. The analysis of this construction shows, in particular, that in the simplest case of the $s\ell (2|1)$ level~1 affine superalgebra the characters are expressed in terms of the Appell elliptic functi

David Ruelle

We consider a quantum spin system consisting of a finite subsystem connected to infinite reservoirs at different temperatures. In this setup we define nonequilibrium steady states and prove that the rate of entropy production in such states is nonnegative.

D. Holcman, I. Kukpa

In this note we present some results concerning the concentration of sequences of first eigenfunctions on the limit sets of a Morse-Smale dynamical system on a compact Riemanniann manifold. More precisely a renormalized sequence of eigenfunctions converges to a measure $μ$ concentrated on the hyperbolic sets of the field. The set of all possible measure turn

Amnon Besser

The finite n-th polylogarithm li_n(z) in Z/p[z] is defined as the sum on k from 1 to p-1 of z^k/k^n. We state and prove the following theorem. Let Li_k:C_p to C_p be the p-adic polylogarithms defined by Coleman. Then a certain linear combination F_n of products of polylogarithms and logarithms, with coefficients which are independent of p, has the property t

J. Denef, F. Loeser

This paper is a survey on arc spaces, a recent topic in algebraic geometry and singularity theory. The geometry of the arc space of an algebraic variety yields several new geometric invariants and brings new light to some classical invariants.

M. Farber

Let $T\subset \R^{m+1}$ be a strictly convex domain bounded by a smooth hypersurface $X=\partial T$. In this paper we find lower bounds on the number of billiard trajectories in $T$ which have a prescribed intial point $A\in X$, a prescribed final point $B\in X$ and make a prescribed number $n$ of reflections at the boundary $X$. We apply a topological appro

Florin Panaite, Dragos Stefan

If A is a bialgebra over a field k and M, N are either left-right Yetter-Drinfel&#39;d modules or left-right Hopf modules over A, we construct deformation cohomologies H^*(M,N) as total cohomologies of certain double complexes Y(M,N) and C(M,N), respectively. In both cases, H^1(M,N) is isomorphic to the group of equivalence classes of extensions of M by N in

Fabien Boniver

We prove the existence and uniqueness of a *projectively equivariant symbol map*, which is an isomorphism between the space of bidifferential operators acting on tensor densities over $R^n$ and that of their symbols, when both are considered as modules over an imbedding of $sl(n+1,\R)$ into polynomial vector fields. The coefficients of the bidifferential ope

S. Cheluvaraja

We present a finite energy topological Z(2) vortex solution in a 2+1 dimensional SO(3) gauge field theory minimally coupled to a matrix valued Higgs field. The vortex carries a Z(2) magnetic charge and obeys a modulo two addition property. The core of this vortex has a structure similar to that of the Abrikosov vortex appearing in a type II superconductor. T

G. Domenech, M. L. Levinas

We develop the WKB expansion to relate Quantum Field Theory variables with those describing macroscopical matter. We find that, up to the first quantum correction, free scalar fields correspond to perfect fluids with pressure. We also find the law of motion for the associated particles which takes into account deviations from the classical trajectories, show

Jeongwon Ho

We show that in general holographic stress tensor may contain a new term of divergence of a spacelike unit normal acceleration. Then, it is shown that in contrast to previous descriptions, a new stress tensor for Kerr-AdS solutions can be a traceless one. Interestingly, this prescription entails a local failure on the IR-UV connection.

Matthias Neubert

Bauer, Ligeti and Luke have recently proposed a new method for measuring |V_{ub}| in inclusive semileptonic B decays, using a cut on the lepton invariant mass to discriminate against b->c transitions. We investigate the structure of the heavy-quark expansion for this case and show that to all orders the magnitude of the leading perturbative and nonperturbati

Martina Brisudova, William H. Kinney

It is possible that there may exist long-range forces in addition to gravity. In this paper we construct a simple model for such a force based on exchange of a massless scalar field and analyze its effect on the evolution of a homogeneous Friedmann-Robertson-Walker cosmology. The presence of such an interaction leads to an equation of state characterized by

I. M. Suslov

An algorithm is proposed for the determination of the asymptotics of a sum of a perturbation series from the given values of its coefficients in the strong-coupling limit. When applied to the Φ^4 theory, the algorithm yields the β(g)\propto g^αbehavior with α\approx 1 at large g for the Gell-Mann - Low function.