arXiv papers from September 1998

M. V. Cougo-Pinto, C. Farina, M. R. Negrao, A. C. Tort

We compute the influence of boundary conditions on the Euler-Heisenberg effective Lagrangian scalar QED scalar for the case of a pure magnetic field. The boundary conditions constrain the quantum scalar field to vanish on two parallel planes separeted by a distance $a$ and the magnetic field is assumed to be constant, uniform and perpendicular to the planes.

Tom Mehen, Iain W. Stewart

The OS and PDS renormalization schemes for the effective field theory with nucleons and pions are investigated. We explain in detail how the renormalization is implemented using local counterterms. Fits to the NN scattering data are performed in the 1S0 and 3S1 channels for different values of mu_R. An error analysis indicates that the range of the theory wi

P. Coleman

I review our incomplete understanding of non-Fermi liquid behavior in heavy fermion systems at a quantum critical point. General considerations suggest that critical antiferromagnetic fluctuations do not destroy the Fermi surface by scattering the heavy electrons- but by actually breaking up the internal structure of the heavy fermion. I contrast the weak, a

D. Becirevic, Ph. Boucaud, L. Giusti, J. P. Leroy

We present the results for light hadron spectrum, decay constants and the quark masses obtained with non-perturbatively improved Wilson fermions. We also give our preliminary results for the heavy-light decay constants.

Alexei V. Tkachenko

The theory of nematic-smectic phase transition in the system of uniform semi-flexible chains with hard-core repulsion is presented. Both the general density-functional formalism the tube-model calculation show that the flexibility of the chains results in a strong first-order transition, in contrast to the common weak-cristallization scenario of the nematic-

H. W. Hamber

Accurate Quantum Gravity calculations, based on the simplicial lattice formulation, are computationally very demanding and require vast amounts of computer resources. A custom-made 64-node parallel supercomputer capable of performing up to $2 \times 10^{10}$ floating point operations per second has been assembled entirely out of commodity components, and has

Amy J. Kolan, Edmund R. Nowak, Alexei V. Tkachenko

We present a theoretical discussion of the reversible parking problem, which appears to be one of the simplest systems exhibiting glassy behavior. The existence of slow relaxation, nontrivial fluctuations, and an annealing effect can all be understood by recognizing that two different time scales are present in the problem. One of these scales corresponds to

M. V. Cougo-Pinto, C. Farina, A. C. Tort

The influence of an external constant uniform magnetic field on the Casimir energy density of a Dirac field under antiperiodic (and periodic) boundary condition is computed by applying Schwinger's proper time method. The result thus obtained shows that in principle, under suitable conditions, the magnetic field can enhance the fermionic Casimir energy densit

R. Brent Tully

A large luminosity--linewidth template sample is now available, improved absorption corrections have been derived, and there are a statistically significant number of galaxies with well determined distances to supply the zero point. A revised estimate of the Hubble Constant is H_0=77 +-4 km/s/Mpc where the error is the 95% probability statistical error. Syst

H. Velazquez, Simon D. M. White

We have carried out a set of self-consistent N-body simulations to study the interaction between disc galaxies and merging satellites with the aim of determining the disc kinematical changes induced by such events. We explore a region of the parameter space embracing satellites with different masses and internal structure and orbits of various eccentricities

Hernan A. Makse, Shlomo Havlin, Peter R. King, H. Eugene Stanley

Granular materials size segregate when exposed to external periodic perturbations such as vibrations. Moreover, mixtures of grains of different sizes spontaneously segregate in the absence of external perturbations: when a mixture is simply poured onto a pile, the large grains are more likely to be found near the base, while the small grains are more likely

Patricio S. Letelier, Samuel R. Oliveira

The static and stationary C-metric are revisited in a generic framework and their interpretations studied in some detail. Specially those with two event horizons, one for the black hole and another for the acceleration. We found that: i) The spacetime of an accelerated static black hole is plagued by either conical singularities or lack of smoothness and com

Alain Messager, Bruno Nachtergaele

We review recent results as well as ongoing work and open problems concerning interface states in quantum spin systems at zero and finite temperature.

Hernan A. Makse, Jose S. Andrade, Michael Batty, Shlomo Havlin

We propose and test a model that describes the morphology of cities, the scaling of the urban perimeter of individual cities, and the area distribution of systems of cities. The model is also consistent with observable urban growth dynamics, our results agreeing both qualitatively and quantitatively with urban data. The resulting growth morphology can be und

M. V. Cougo-Pinto, C. Farina, M. R. Negrao, A. C. Tort

We compute the influence of an external magnetic field on the Casimir energy of a massive charged scalar field confined between two parallel infinite plates. For this case the obtained result shows that the magnetic field inhibits the Casimir effect.

Pierre Cizeau, Hernan A. Makse, H. Eugene Stanley

Spontaneous stratification of granular mixtures has been reported by Makse et al. [Nature 386, 379 (1997)] when a mixture of grains differing in size and shape is poured in a quasi-two-dimensional heap. We study this phenomenon using two different approaches. First, we introduce a cellular automaton model that illustrates clearly the physical mechanism; the

B. I. Shklovskii

A simple electrostatic theory of condensation of rod-like polyelectrolytes under influence of polyvalent ions is proposed. It is based on the idea that Manning condensation of ions results in formation of the Wigner crystal on a background of a bundle of rods. It is shown that, depending on a single dimensionless parameter, this can be the densely packed thr

Hernan A. Makse, Robin C. Ball, H. Eugene Stanley, Stephen Warr

Spontaneous stratification in granular mixtures has been recently reported by H. A. Makse et al. [Nature 386, 379 (1997)]. Here we study experimentally the dynamical processes leading to spontaneous stratification. Using a high-speed video camera, we study a rapid flow regime where the rolling grains size segregate during the avalanche. We characterize the d

Charles D. Dermer, Kurt E. Mitman

We have developed a computer model to calculate gamma ray burst (GRB) light curves and efficiencies from the interaction of a single, thin blast wave with clouds in the external medium. Large amplitude, spiky variability occurs when the clouds have radii r << R/Gamma, where R is the mean distance of a cloud from the GRB source and Gamma is the blast-wave Lor

Art M. Duval

\newcommand{\rhomi}[1]{\widetilde{H}_{#1}} \newcommand{\rbeti}[1]{\beta_{#1}} \newcommand{\kk}{\mathbf k} \newcommand{\dimk}{\dim_{\kk}} We show that algebraically shifting a pair of simplicial complexes weakly increases their relative homology Betti numbers in every dimension. More precisely, let $\Delta(K)$ denote the algebraically shifted complex of simpl

Hernan A. Makse

We study the segregation of granular mixtures in two-dimensional silos using a set of coupled equations for surface flows of grains. We study the thick flow regime, where the grains are segregated in the rolling phase. We incorporate this dynamical segregation process, called kinematic sieving, free-surface segregation or percolation, into the theoretical fo

Hernan A. Makse, Hans J. Herrmann

We study segregation and stratification of mixtures of grains differing in size, shape and material properties poured in two-dimensional silos using a microscopic lattice model for surface flows of grains. The model incorporates the dissipation of energy in collisions between rolling and static grains and an energy barrier describing the geometrical asperiti

Hernan A. Makse

When a mixture of two kinds of grains differing in size and shape is poured in a vertical two-dimensional cell, the mixture spontaneously stratifies in alternating layers of small and large grains, whenever the large grains are more faceted than the small grains. Otherwise, the mixture spontaneously segregates in different regions of the cell when the large

Hernan A. Makse

We study segregation of granular mixtures in the continuous avalanche regime (for frequencies above ~ 1 rpm) in thin rotating drums using a continuum theory for surface flows of grains. The theory predicts profiles in agreement with experiments only when we consider a flux dependent velocity of flowing grains. We find the segregation of species of different

Hernan A. Makse, Pierre Cizeau, H. Eugene Stanley

We propose a mechanism to explain what occurs when a mixture of grains of different sizes and different shapes (i.e. different repose angles) is poured into a quasi-two-dimensional cell. Specifically, we develop a model that displays spontaneous stratification of the large and small grains in alternating layers. We find that the key requirement for stratific

Katarzyna Pietruska-Paluba

In this paper we identify the domain of the Dirichlet form associated with the Brownian motion on simple nested fractals with an integral Lipschitz space. This result generalizes such an identification on the Sierpi\'nski gasket, carried on by Jonsson.

Luis A. Nunes Amaral, Hernan A. Makse

We comment on a recent Letter by Maunuksela et al. [Phys. Rev. Lett. 79, 1515 (1997)].

Philippe Biane

This is an introduction to some of the most probabilistic aspects of free probability theory.

Siye Wu

Consider a holomorphic torus action on a possibly non-compact K\"ahler manifold. We show that the higher cohomology groups appearing in the geometric quantization of the symplectic quotient are isomorphic to the invariant parts of the corresponding cohomology groups of the original manifold. For non-Abelian group actions on compact K\"ahler manifolds, this r

Oscar Rodríguez de la Fuente, José M. Soler

Using molecular dynamics simulations, with a realistic many-body embedded-atom potential, and a novel method to characterize local order, we study the structure of pure nickel during the rapid quench of the liquid and in the resulting glass. In contrast with previous simulations with pair potentials, we find more crystalline order and fewer icosahedra for sl

R. M. Weiner

Invited talk at the CORR98 meeting on Correlations, M\'atrah\'aza, June 1998, to appear in the proceedings of the meeting in World Scientific. This talk is dedicated to the memory of Peter Carruthers.

Hirotaka Kikyo

For a theory $T$ in $L, T_\sigma$ is the theory of the models of $T$ with an automorphism $\sigma$. If $T$ is an unstable model complete theory without the independence property, then $T_\sigma$ has no model companion. If $T$ is an unstable model complete theory and $T_\sigma$ has the amalgamation property, then $T_\sigma$ has no model companion. If $T$ is m

P. Chandra, L. B. Ioffe, D. Sherrington

We present an analytic enumeration of the metastable states, $N_s$, in a periodic long-range Josephson array frustrated by a transverse field. We find that the configurational entropy, $S_{conf} \equiv \ln N_s$, is extensive and scales with frustration, confirming that the non-random system is glassy. We also find that $S_{conf}$ is different from that of it

Ehud Hrushovski, Thomas Scanlon

We note here, in answer to a question of Poizat, that the Morley and Lascar ranks need not coincide in differentially closed fields. We approach this through the (perhaps) more fundamental issue of the variation of Morley rank in families.

R. Aloisio, V. Azcoiti, G. Di Carlo, A. Galante

In the large fermion mass limit of QCD at finite density the structure of the partition function greatly simplifies and can be studied analytically. We show that, contrary to general wisdom, the phase of the Dirac determinant is relevant only at finite temperature and can be neglected for zero temperature fields.

Anand Pillay, Thomas Scanlon, Frank Wagner

It is proved that any supersimple field has trivial Brauer group, and more generally that any supersimple division ring is commutative. As prerequisites we prove several results about generic types in groups and fields whose theory is simple.

Thomas Scanlon, José Felipe Voloch

The work of Chatzidakis and Hrushovski on the model theory of difference fields in characteristic zero showed that groups defined by difference equations have a very restricted structure. Recent work of Chatzidakis, Hrushovski and Peterzil [CHP] extends the class of difference fields for which this sort of result is known to positive characteristic. In this

A. D. Dolgov, S. H. Hansen, S. Pastor, D. V. Semikoz

The impact of unstable Majorana tau neutrinos on primordial nucleosynthesis is considered. The mass and lifetime of nu_tau are taken in the intervals 0.1-20 MeV and 0.001-400 sec respectively. The studied decay modes are nu_tau -> nu_mu + phi and nu_tau -> nu_e + phi, where phi is a massless (or light) scalar. Integro-differential kinetic equations are solve

E. Mukhin, A. Varchenko

The quantized Knizhnik-Zamolodchikov equation is a difference equation defined in terms of rational $R$ matrices. We describe all singularities of hypergeometric solutions to the qKZ equations.

Piotr T. Chruściel

We prove non-existence of static, vacuum, appropriately regular, asymptotically flat black hole space-times with degenerate (not necessarily connected) components of the event horizon. This finishes the classification of static, vacuum, asymptotically flat domains of outer communication in an appropriate class of space-times, showing that the domains of oute

Paolo Pasti, Dmitri Sorokin, Mario Tonin

To construct actions for describing superbranes propagating in AdS x S superbackgrounds we propose a coset space realization of these superbackgrounds which results in a short polynomial fermionic dependence (up to the sixth power in Grassmann coordinates) of target superspace supervielbeins and superconnections. Gauge fixing kappa-symmetry in a way compatib

Richard F. Lebed

Since QCD is believed to be the underlying theory of the strong interaction, it is appropriate to study techniques that take into account more features of its rich and complex structure. We begin by discussing aspects of physics that are ill-reproduced by the usual one- or two-meson exchange approaches and identify the source of the deficiencies of these mod

Robert Bluhm, Alan Kostelecky, Neil Russell

This talk discusses the sensitivity of electron-positron and proton-antiproton Penning-trap experiments to CPT- and Lorentz-violating effects in the context of an extension of the minimal standard model and quantum electrodynamics.

A. A. Rodrigues Sobreira, E. R. Bezerra de Mello

We study the classical and quantum motion of a relativistic charged particle on the spacetime produced by a global monopole. The self-potential, which is present in this spacetime, is considered as an external electrostatic potential. We obtain classical orbits and quantum states for a spin-1/2 and spin-0 particles.

Wolfgang B. Thimm, Johann Kroha, Jan von Delft

We study the Kondo effect generated by a single magnetic impurity embedded in an ultrasmall metallic grain, to be called a ``Kondo box''. We find that the Kondo resonance is strongly affected when the mean level spacing in the grain becomes larger than the Kondo temperature, in a way that depends on the parity of the number of electrons on the grain. We show

C. A. Collins

A primeval galaxy represents the earliest stages of a galaxy's life and as such provides clues to the early history of the Universe and the evolution of stars and galaxies. Over the last 20 years astronomers have been engaged in the quest to detect the faint signals from these objects, believed to lie at a distance comparable with the size of the Universe. A

James A. Hoagland, Raju Pandey, Karl N. Levitt

A security policy states the acceptable actions of an information system, as the actions bear on security. There is a pressing need for organizations to declare their security policies, even informal statements would be better than the current practice. But, formal policy statements are preferable to support (1) reasoning about policies, e.g., for consistenc

Denis R. Bell, Salah E. -A. Mohammed

Let $L$ be an infinitely degenerate second-order linear operator defined on a bounded smooth Euclidean domain. Under weaker conditions than those of H\"ormander, we show that the Dirichlet problem associated with $L$ has a unique smooth classical solution. The proof uses the Malliavin calculus. At present, there appears to be no proof of this result using cl

Jose Burillo, Sean Cleary, Melanie Stein

The distance from the origin in the word metric for generalizations F(p) of Thompson's group F is quasi-isometric to the number of carets in the reduced rooted tree diagrams representing the elements of F(p). This interpretation of the metric is used to prove that every F(p) admits a quasi-isometric embedding into every F(q), and also to study the behavior o

Guido Altarelli, Ferruccio Feruglio

We discuss models of neutrino masses that lead to a large mixing angle for atmospheric neutrino oscillations. In particular we study a mechanism where a simple texture for the Dirac matrix leads to the observed pattern of mixings for a continuous range of Majorana matrices in a reasonably natural way. Both nearly maximal and small mixing solutions for solar

E. Elizalde, D. V. Vassilevich

We consider the four dimensional Euclidean Maxwell theory with a Chern-Simons term on the boundary. The corresponding gauge invariant boundary conditions become dependent on tangential derivatives. Taking the four-sphere as a particular example, we calculate explicitly a number of the first heat kernel coefficients and obtain the general formulas that yields

Carl E. Carlson

We review standard applications of perturbative QCD to baryon production, and argue by examining data that it is generally relevant at high but experimentally feasible momentum transfers. Then we consider some new initiatives, particularly meson photoproduction off baryons and the seeming quagmire of Delta(1232) electroproduction.

M. Knecht, S. Peris, E. de Rafael

The pi^+ - pi^0 mass difference generated by the electroweak interactions of the Standard Model is expressed, to lowest order in the chiral expansion and to leading order in alpha, in terms of an integral involving the same correlation function Pi_{LR}(Q^2) which governs the well known electromagnetic pi^+ - pi^0 mass difference. We calculate this contributi

Bradford W. Greeley, William P. Blair, Knox S. Long, John C. Raymond

Using the Hopkins Ultraviolet Telescope (HUT), we have obtained 850-1850 angstrom spectra of the magnetic cataclysmic variable star AM Her in the high state. These observations provide high time resolution spectra of AM Her in the FUV and sample much of the orbital period of the system. The spectra are not well-modelled in terms of simple white dwarf (WD) at

Ruediger Scheibl, Ulrich Heinz

Using a density matrix approach to describe the process of coalescence, we calculate the coalescence probabilities and invariant momentum spectra for deuterons and antideuterons. We evaluate our expressions with a hydrodynamically motivated parametrization for the source at freeze-out which implements rapid collective expansion of the collision zone formed i

Eric C. Ford, Michiel van der Klis, Jan van Paradijs, Mariano Mendez

In recent observations with the Rossi X-Ray Timing Explorer we have detected two simultaneous quasi-periodic oscillation (QPO) peaks in the low mass X-ray binary and atoll source 4U 1735-44. The lower and higher frequency QPOs have frequencies varying between 632 and 729 Hz, and 982 and 1026 Hz, respectively. The fractional rms amplitudes are 3.7 to 8.1% and

Joseph M. Landsberg

This is an expanded and updated version of a lecture series I gave at Seoul National University in September 1997. It is in some sense an update of the 1979 Griffiths and Harris paper with a similar title. I discuss: Homogeneous varieties, Topology and consequences Projective differential invariants, Varieties with degenerate Gauss images, When can a unirule

Anders Irbäck, Carsten Peterson, Frank Potthast, Erik Sandelin

Background: Designing amino acid sequences that are stable in a given target structure amounts to maximizing a conditional probability. A straightforward approach to accomplish this is a nested Monte Carlo where the conformation space is explored over and over again for different fixed sequences, which requires excessive computational demand. Several approxi

Liang Zuo-tang

We suggested that longitudinal polarization of Lambda produced in e+e- annihilation at LEP energies can provide useful information on hadronization mechanism in general and on testing the validity of different pictures for the spin content of baryon in describing the fragmentation process in particular. We present the results obtained from the calculations b

F. Cardarelli, E. Pace, G. Salme', S. Simula

The momentum distributions of the constituent quarks inside the nucleon and the prominent electroproduced nucleon resonances are investigated in the two most sophisticated, available quark potential models, based respectively on the assumption of the valence + gluon dominance and on the exchange of the pseudoscalar Goldstone-bosons arising from the spontaneo

Michael Strickland

We present results of numerical solutions of Schwinger-Dyson equations for the finite-temperature quark and electron propagators. It is shown that both strongly coupled QED and QCD undergo a chiral symmetry restoring phase transition as the temperature is increased. We go beyond the bare vertex or "rainbow" approximation by applying the finite-temperature Wa

Lubomir Gavrilov

Consider an ordinary differential equation which has a Lax pair representation A'(x)= [A(x),B(x)], where A(x) is a matrix polynomial with a fixed regular leading coefficient and the matrix B(x) depends only onA(x). Such an equation can be considered as a completely integrable complex Hamiltonian system. We show that the generic complex invariant manifold {A(

Michael Fleischhauer, Oliver Veits

We analyze the long-time quantum dynamics of degenerate parametric down-conversion from an initial sub-harmonic vacuum (spontaenous down-conversion). Standard linearization of the Heisenberg equations of motions fails in this case, since it is based on an expansion around an unstable classical solution and neglects pump depletion. Introducing a mean-field ap

J. Z. Sun, D. W. Abraham, R. A. Rao, C. B. Eom

To understand the near-interface magnetism in manganites, uniform, ultra-thin films of La_{0.67}Sr_{0.33}MnO_3 were grown epitaxially on single crystal (001) LaAlO_3 and (110) NdGaO_3 substrates. The temperature and magnetic field dependent film resistance is used to probe the film's structural and magnetic properties. A surface and/or interface related dead

James J. Kelly

The sensitivity of momentum distributions, recoil polarization observables, and response functions for nucleon knockout by polarized electrons to channel coupling in final-state interactions is investigated using a model in which both the distorting and the coupling potentials are constructed by folding density-dependent effective interactions with nuclear t

S. Kotkovsky, I. M. Narodetskii, K. A. Ter-Martirosyan, S. Simula

We derive a new parton formula for the inclusive B decays and briefly discuss its applications to semileptonic and weak radiative decays of the B-meson.

Marie-Liesse Doublet, Marie-Bernadette Lepetit

The present work studies the quasi one-dimensional $Ni(dmit)_2$-based compounds within a correlated model. More specifically, we focus our attention on the composed influence of the electronic dimerization-factor and the repulsion, on the transport properties and the localization of the electronic density in the ground-state. Those properties are studied thr

Marc Sher

The simplest extension of the standard model involves adding a scalar doublet--the so-called two-Higgs model. In general, the additional scalar will mediate tree-level flavor-changing neutral currents. Although one can arbitrarily impose a discrete symmetry to avoid these, it isn't necessary to do so; reasonable assumptions about the size of the flavor-chang

Igor Batalin, Robert Marnelius

Recently it has been shown that antibrackets may be expressed in terms of Poisson brackets and vice versa for commuting functions in the original bracket. Here we also introduce generalized brackets involving higher antibrackets or higher Poisson brackets where the latter are of a new type. We give generating functions for these brackets for functions in arb

Robert J. Nemiroff, J. Bruce Rafert

It is currently feasible to start a continuous digital record of the entire sky sensitive to any visual magnitude brighter than 15 each night. Such a record could be created with a modest array of small telescopes, which collectively generate no more than a few Gigabytes of data daily. Alternatively, a few small telescopes could continually re-point to scan

Igor Batalin, Robert Marnelius

The recently presented quantum antibrackets are generalized to quantum Sp(2)-antibrackets. For the class of commuting operators there are true quantum versions of the classical Sp(2)-antibrackets. For arbitrary operators we have a generalized bracket structure involving higher Sp(2)-antibrackets. It is shown that these quantum antibrackets may be obtained fr

Ubiraci P. C. Neves, J. R. Drugowich de Felicio

We investigate two-dimensional Ising systems with multisping interactions of three- (m=3) and four-body terms (m=4). The application of a new type of finite-size algorithm of de Oliveira allow us to clearly distinguish a first-order transition (in the m=4 case) from a continuous one (in the m=3 one). We also study the damage spreading in these systems. In th

Hans-Juergen Matschull

When two point particles, coupled to three dimensional gravity with a negative cosmological constant, approach each other with a sufficiently large center of mass energy, then a BTZ black hole is created. An explicit solution to the Einstein equations is presented, describing the collapse of two massless particles into a non-rotating black hole. Some general

A. I. Davydychev, A. G. Grozin

The effect of non-zero c quark mass on b quark HQET Lagrangian, up to 1/m_b level, is calculated at two loops. The results are expressed in terms of dilogarithmic functions of m_c/m_b. This calculation involves on-shell two-loop propagator-type diagrams with two different masses, m_b and m_c. A general algorithm for reducing such Feynman integrals to the bas

C. Ford, T. Tok, A. Wipf

We consider Yang-Mills theories with general gauge groups $G$ and twists on the four torus. We find consistent boundary conditions for gauge fields in all instanton sectors. An extended Abelian projection with respect to the Polyakov loop operator is presented, where $A_0$ is independent of time and in the Cartan subalgebra. Fundamental domains for the gauge

A. Werner, F. Schmid, M. Mueller, K. Binder

A popular concept which describes the structure of polymer interfaces by ``intrinsic profiles'' centered around a two dimensional surface, the ``local interface position'', is tested by extensive Monte Carlo simulations of interfaces between demixed homopolymer phases in symmetric binary (AB) homopolymer blends, using the bond fluctuation model. The simulati

R. A Broglia, G. Tiana, H. E. Roman, E. Vigezzi

The stability of model proteins with designed sequences is assessed in terms of the number of sequences (obtained from the designed sequence through mutations), which fold into 5the ``native'' conformation. By a complete enumeration of the total number of sequences obtained by introducing up to 4 point mutations and up to 7 composition--conserving mutations

Rupert A. C. Croft, David H. Weinberg, Max Pettini, Lars Hernquist

We measure the linear power spectrum of mass density fluctuations at redshift z=2.5 from the \lya forest absorption in a sample of 19 QSO spectra, using the method introduced by Croft et al. (1998). The P(k) measurement covers the range 2\pi/k ~ 450-2350 km/s (2-12 comoving \hmpc for \Omega=1). We examine a number of possible sources of systematic error and

Sigmund Kohler, Thomas Dittrich, Peter Hänggi

Using the parametrically driven harmonic oscillator as a working example, we study two different Markovian approaches to the quantum dynamics of a periodically driven system with dissipation. In the simpler approach, the driving enters the master equation for the reduced density operator only in the Hamiltonian term. An improved master equation is achieved b

V. A. Savchenko, T. P. Shestakova, G. M. Vereshkov

The paper is the first of two parts of the work devoted to the investigation of constructing quantum theory of a closed universe as a system without asynptotic states. In Part I the role of asymptotic states in quantum theory of gravity is discussed, that enables us to argue that mathematically correct quantum geometrodynamics of a closed universe has to be

Carlos Sopuerta, Roy Maartens, George Ellis, William Lesame

In a cold matter universe, the linearized gravito-magnetic tensor field satisfies a transverse condition (vanishing divergence) when it is purely radiative. We show that in the nonlinear theory, it is no longer possible to maintain the transverse condition, since it leads to a non-terminating chain of integrability conditions. These conditions are highly res

Wojciech Satula

Various properties of single-particle Hartree-Fock ground-state solutions in $N\sim Z$ nuclei are investigated. The emphasis is on a role of single-particle mean-field in odd-even mass staggering. It is shown that, unlike in traditional scenario originating from the Fermi gas or macroscopic models, the symmetry energy contribution to odd-even mass staggering

B. W. Miller, J. M. Lotz, H. C. Ferguson, M. Stiavelli

The specific globular cluster frequencies (S_N) for 24 dwarf elliptical (dE) galaxies in the Virgo and Fornax Clusters and the Leo Group imaged with the Hubble Space Telescope are presented. Combining all available data, we find that for nucleated dEs --- which are spatially distributed like giant ellipticals in galaxy clusters --- S_N(dE,N)=6.5 +- 1.2 and S

F. Della Sala, A. Di Carlo, P. Lugli, F. Bernardini

The free-carrier screening of macroscopic polarization fields in wurtzite GaN/InGaN quantum wells lasers is investigated via a self-consistent tight-binding approach. We show that the high carrier concentrations found experimentally in nitride laser structures effectively screen the built-in spontaneous and piezoelectric polarization fields, thus inducing a

G. Battistoni

In view of the interpretation of data collected by large, deep underground experiments in terms of primary Cosmic Ray physics, this work is focused on the study of the production of of TeV muons in Extensive Air Showers. The review tries to point out those features of hadronic interactions that mostly affect the production of the high energy muons. A few dif

Bozhidar Z. Iliev

The theory of linear transports along paths in vector bundles, generalizing the parallel transports generated by linear connections, is developed. The normal frames for them are defined as ones in which their matrices are the identity matrix or their coefficients vanish. A number of results, including theorems of existence and uniqueness, concerning normal f

Rainer Hegger, Holger Kantz, Thomas Schreiber

Nonlinear time series analysis is becoming a more and more reliable tool for the study of complicated dynamics from measurements. The concept of low-dimensional chaos has proven to be fruitful in the understanding of many complex phenomena despite the fact that very few natural systems have actually been found to be low dimensional deterministic in the sense

A. G. Green

The quantum Hall ferromagnet at filling fraction $\nu = 1$ has some unusual properties due to the remarkable identity between the topological density of a spin distortion and the associated electrical charge density. We investigate the localization of spinwaves by coupling to a scalar disorder potential via their topological density. A low energy description

T. Ootsuka, S. Miyagi, Y. Yasui, S. Zeze

Anti-self-dual (ASD) Maxwell solutions on 4-dimensional hyperk\"ahler manifolds are constructed. The N=2 supersymmetric half-flat equations are derived in the context of the Ashtekar formulation of N=2 supergravity. These equations show that the ASD Maxwell solutions have a direct connection with the solutions of the reduced N=2 supersymmetric ASD Yang-Mills

T. Miyaji, G. Hasinger, M. Schmidt

We present the results and parameterization of the 0.5-2 keV Luminosity Function of AGNs from various ROSAT Surveys, ranging from the ROSAT bright Survey from the ROSAT All-Sky Survey (RASS) to the Ultra-Deep survey on the Lockman hole. A Luminosity-dependent density evolution model, where the density evolution rate drops at low luminosities, gives an excell

S. T. Petcov

It is shown that the $\nu_2 \to \nu_{e}$ and $\nu_{\mu} \to \nu_{e}$ ($\nu_e \to \nu_{\mu (\tau)}$) transitions respectively of the solar and atmospheric neutrinos in the Earth in the case of $\nu_e - \nu_{\mu (\tau)}$ mixing in vacuum, are strongly enhanced by a new type of resonance when the neutrinos cross the Earth core. The resonance is operative at sma

D. D. Betts, J. Schulenburg, G. E. Stewart, J. Richter

Here we generate finite bipartite body-centred cubic lattices up to 32 vertices. We have studied the spin one half Heisenberg antiferromagnet by diagonalizing its Hamiltonian on each of the finite lattices and hence computing its ground state properties. By extrapolation of these data we obtain estimates of the T = 0 properties on the infinite bcc lattice. O

Uwe Hansen, Peter Vogl, Vincenzo Fiorentini

We present simulations of metallization morphologies under ionized sputter deposition conditions, obtained by a new theoretical approach. By means of molecular dynamics simulations using a carefully designed interaction potential, we analyze the surface adsorption, reflection, and etching reactions taking place during Al physical vapor deposition, and calcul

Remo Garattini

We use variational methods to calculate quasilocal energy quantum corrections. A comparison with the effective potential calculated at quadratic order is made by means of gaussian wave functionals. The method is a particular case of the effective action for composite operators used in quantum field theory. In pure gravity the method is applied for the first

Y. P. Jing

The density profile and the clustering of dark matter (DM) halos are two very important ingredients for understanding many observations of galaxies. In this talk, I present our new results for these two quantities from a large set of high quality N-body simulations. We show that in an Einstein de Sitter Universe about 35 percent of the halos could not be fit

Yasumasa Hasegawa

The Josephson effect between triplet and singlet superconductors is studied. Josephson current can flow between triplet and singlet superconductors due to the spin-orbit coupling in the spin-triplet superconductor but it is finite only when triplet superconductor has $L_z=-S_z=\pm 1$, where $L_z$ and $S_z$ are the perpendicular components of orbital angular

J. Ginibre, G. Velo

We study the theory of scattering in the energy space for the Hartree equation in space dimension n>2. Using the method of Morawetz and Strauss, we prove in particular asymptotic completeness for radial nonnegative nonincreasing potentials satisfying suitable regularity properties at the origin and suitable decay properties at infinity. The results cover in

P. Colangelo, F. De Fazio, N. Paver

We review several aspects of the phenomenology of P-wave $\bar q Q$ mesons: mass splittings, effective strong couplings and leptonic constants. We also describe a QCD sum rule determination to order $\alpha_s$ of the form factor $\tau_{1/2}(y)$ governing the semileptonic $B$ decays to the charm doublet with $J^P=(0^+_{1/2},1^+_{1/2})$.

PACS Collaboration, S. Aoki, G. Boyd, R. Burkhalter

We report results on the static quark potential in two-flavor full QCD. The calculation is performed for three values of lattice spacing $a^{-1}\approx 0.9, 1.3$ and 2.5 GeV on $12^3{\times}24, 16^3{\times}32$ and $24^3{\times}48$ lattices respectively, at sea quark masses corresponding to $m_\pi/m_\rho \approx 0.8-0.6$. An RG-improved gauge action and a tad

The OPAL Collaboration, G. Abbiendi et al

A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 57 pb-1 at centre-of-mass energies of 181-184 GeV taken with the OPAL detector at LEP. No evidence for chargino or neutralino production has been found. Upper limits on chargino and neutralino pair production cross-sections are obtained as