December 1999 arXiv papers — page 17

D0 collaboration, B. Abbott

Events in PbarP collisions at sqrt(s)=1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale Lambda_LL for compositeness in quarks, assuming a model with a left-left isoscalar

Aníbal Iucci, Carlos Naón

We compute the 2-point (equal-time) electronic Green function in a Tomonaga-Luttinger system with long-range electron-electron interactions. We obtain an analytical expression for a "super long-range" potential of the form $V(x)=\frac{e^2d^{-ε}}{|x|^{1-ε}}$. As a consistency check of our computational technique we also consider the particular case of

C. Q. Huang, H. Kröger, X. Q. Luo, K. J. M. Moriarty

In order to extend the recently proposed Monte Carlo Hamiltonian to many-body systems, we suggest to concept of a stochastic basis. We apply it to the chain of $N_s=9$ coupled anharmonic oscillators. We compute the spectrum of excited states in a finite energy window and thermodynamical observables free energy, average energy, entropy and specific heat in a

B. C. Allanach, J. J. van der Bij, A. Dedes, A. Djouadi

The Beyond the Standard Model Working Group discussed a variety of topics relating to exotic searches at current and future colliders, and the phenomenology of current models beyond the Standard Model. For example, various supersymmetric (SUSY) and extra dimensions search possibilities and constraints are presented. Fine-tuning implications of SUSY searches

Junjiro Noguchi, Joerg Winkelmann, Katsutoshi Yamanoi

Let f:C -> A be an entire holomorphic curve into a semi-Abelian variety A. Then the Zariski closure of f(C) is a translate of a semi-Abelian subvariety of A (logarithmic Bloch-Ochiai's theorem). The purpose of the present paper is to establish a quantitative version of the above result for such f i.e., the second main theorem and the defect relation.

A. Mironov, A. Morozov

Elementary MAPLE calculations are used to support the claim of hep-th/9906240 that the ratios of theta-functions, associated with the Seiberg-Witten complex curves, provide Poisson-commuting Hamiltonians which describe the dual of the original Seiberg-Witten integrable system.

Christos Tsagas, Roy Maartens

Motivated by the isotropy of the CMB spectrum, all existing studies of magnetised cosmological perturbations employ FRW backgrounds. However, it is important, to know the limits of this approximation and the effects one loses by neglecting the anisotropy of the background magnetic field. We develop a new treatment, which fully incorporates the anisotropic ma

D. Binosi, T. ter Veldhuis

We investigate domain wall junctions in a generalized Wess-Zumino model with a Z(N) symmetry. We present a method to identify the junctions which are potentially BPS saturated. We then use a numerical simulation to show that those junctions indeed saturate the BPS bound for N=4. In addition, we study the decay of unstable non-BPS junctions.

Ulf-G. Meißner, J. A. Oller

We develop a novel approach to chiral meson-baryon dynamics incorporating unitarity constraints and explicit resonance fields. It is based on the most general structure of any pion-nucleon partial wave amplitude neglecting the unphysical cuts as derived from the N/D method. This amplitude is then matched to the one-loop heavy baryon chiral perturbation theor

Kevin Krisciunas, N. C. Hastings, Karen Loomis, Russet McMillan

From an analysis of SNe 1972E, 1980N, 1981B, 1981D, 1983R, 1998bu, 1999cl, and 1999cp we find that the intrinsic V-K colors of Type Ia SNe with multi-color light curve shape (MLCS) parameter -0.4 < Delta < +0.2 suggest a uniform color curve. V-K colors become bluer linearly with time from roughly one week before B-band maximum until one week after maximum, a

Andrea Romanino, Alessandro Strumia

It has been recently claimed that very large values of a universal soft mass term m_0 for sfermions and higgs bosons become natural when M_top is close to 175 GeV if tanβ\approx 10. We show that very large values of m_0 require accidental cancellations not guaranteed by experimental data or theoretical assumptions, and consequently an unnatural fine-tuning o

C M Palmer, T P Devereaux

We present the results of three-dimensional molecular dynamics simulations of vortices which indicate that, for B greater than the matching field, the enhanced pinning effectiveness of splayed columnar defects relative to vertical columnar defects can be explained in terms of the existence or absence of channels through which the vortices can flow without en

Tom Leinster

Informally, a homotopy monoid is a monoid-like structure in which properties such as associativity only hold `up to homotopy&#39; in some consistent way. This short paper comprises a rigorous definition of homotopy monoid and a brief analysis of some examples. It is a much-abbreviated version of the paper `Homotopy Algebras for Operads&#39; (math.QA/0002180)

Ludger Santen, Werner Krauth

The glass transition can simply be viewed as the point at which the viscosity of a structurally disordered liquid reaches 10^{13} Poise [1]. This definition is operational but it sidesteps fundamental controversies about the glass: Is the transition a purely dynamical phenomenon [2]? This would mean that ergodicity gets broken, but that thermodynamic propert

J. A. Peacock, M. Rowan-Robinson, A. W. Blain, J. S. Dunlop

We use an 850-micron SCUBA map of the HDF to study the dust properties of optically-selected starburst galaxies at high redshift. Although the 850-micron map does not allow detection of the majority of individual sources, we show that the galaxies with the highest UV star-formation rates are detected statistically, with a flux density of about S_{850}=0.2 mJ

Jean-Loup Gervais, Henning Samtleben

The superspace flatness conditions which are equivalent to the field equations of supersymmetric Yang-Mills theory in ten dimensions have not been useful so far to derive non trivial classical solutions. Recently, modified flatness conditions were proposed, which are explicitly integrable (hep-th/9811108), and are based on the breaking of symmetry SO(9,1) ->

L. N. da Costa, M. Bernardi, M. V. Alonso, G. Wegner

We use the recently completed redshift-distance survey of nearby early-type galaxies (ENEAR) to measure the dipole component of the peculiar velocity field to a depth of cz ~ 6000 km/s. The sample consists of 1145 galaxies brighter than m_B=14.5 and cz < 7000 km/s, uniformly distributed over the whole sky, and 129 fainter cluster galaxies within the same vol

Martin Bojowald, Thomas Strobl

The recently proposed projection quantization, which is a method to quantize particular subspaces of systems with known quantum theory, is shown to yield a genuine quantization in several cases. This may be inferred from exact results established within symplectic cutting.

Jerome P. Gauntlett, Nakwoo Kim, Jaemo Park, Piljin Yi

We determine the low energy dynamics of monopoles in pure N=2 Yang-Mills theories for points in the vacuum moduli space where the two Higgs fields are not aligned. The dynamics is governed by a supersymmetric quantum mechanics with potential terms and four real supercharges. The corresponding superalgebra contains a central charge but nevertheless supersymme

Tommy Ohlsson, Hakan Snellman

Analytic formulas are presented for three flavor neutrino oscillations in matter in the plane wave approximation. We calculate in particular the time evolution operator in both mass and flavor bases. We also find the transition probabilities expressed as functions of the vacuum mass squared differences, the vacuum mixing angles, and the matter density parame

M. O. Katanaev

The method of conformal blocks for construction of global solutions in gravity for a two-dimensional metric having one Killing vector field is described.

A. J. Benson, F. R. Pearce, C. S. Frenk, C. M. Baugh

We compare the statistical properties of galaxies found in two different models of hierarchical galaxy formation: the semi-analytic model of Cole et al. and the smoothed particle hydrodynamics (SPH) simulations of Pearce et al. Using a `stripped-down&#39; version of the semi-analytic model which mimics the resolution of the SPH simulations and excludes physi

Z. Idziaszek, K. Rzazewski, M. Lewenstein

A scattering of short, weak, nonresonant laser pulses on a Bose-Einstein condensate is proposed as a tool for studying its statistical properties. We show in particular that the variance of the number of scattered photons may distinguish between the Poisson and microcanonical statistics.

J. Dennett-Thorpe, A. G. de Bruyn

We report on the discovery of a source which exhibits over 300% amplitude changes in radio flux density on the period of hours. This source, J1819+3845, is the most extremely variable extragalactic source known in the radio sky. We believe these properties are due to interstellar scintillation, and show that the source must emit at least 55% of its flux dens

Edward Witten

We explore two different problems in string theory in which duality relates an ordinary p-form in one theory to a self-dual (p+1)-form in another theory. One problem involves comparing D4-branes to M5-branes, and the other involves comparing the Ramond-Ramond forms in Type IIA and Type IIB superstring theory. In each case, a subtle topological effect involvi

Mian Wang

In this paper the scalar-tensor theory of gravity is assumed to describe the evolution of the universe and the gravitational scalar $ϕ$ is ascribed to play the role of inflaton. The theory is characterized by the specified coupling function $ω(ϕ)$ and the cosmological function $λ(ϕ)$. The function $λ(ϕ)$ is nearly constant for $0<ϕ<0.1$ and $λ(1)=0$. The fun

Sinya Aoki

We review progress in lattice QCD, focusing on efforts to calculate weak matrix elements relevant for the determination of the Cabibbo-Kobayashi-Maskawa matrix. Topics we discuss include light hadron spectrum and quark masses, CP-violation in K meson decays and weak matrix elements of heavy-light mesons.

Steven H. Simon

A device is proposed that is similar in spirit to the electron turnstile except that it operates within a quantum Hall fluid. In the integer quantum Hall regime, this device pumps an integer number of electrons per cycle. In the fractional regime, it pumps an integer number of fractionally charged quasiparticles per cycle. It is proposed that such a device c

Dongsu Bak, Kimyeong Lee, Piljin Yi

We find the most general low energy dynamics of 1/2 BPS monopoles in the N=4 supersymmetric Yang-Mills theories (SYM) when all six adjoint Higgs expectation values are turned on. When only one Higgs is turned on, the Lagrangian is purely kinetic. When all six are turned on, however, this moduli space dynamics is augmented by five independent potential terms,

A. A. Abrikosov, E. Gozzi

Starting from a functional formulation of classical mechanics, we show how to perform its quantization by freezing to zero two Grassmannian partners of time.

Alexander R. Kessel, Vladimir L. Ermakov

It is proposed that the state space of a quantum object with a complicated discrete spectrum can be used as a basis for multiqubit recording and processing of information in a quantum computer. As an example, nuclear spin 3/2 is considered. The possibilities of writing and reading two quantum bits of information, preparation of the initial state, implementat

M. D. Lukin, S. F. Yelin, M. Fleischhauer

We describe a general technique that allows for an ideal transfer of quantum correlations between light fields and metastable states of matter. The technique is based on trapping quantum states of photons in coherently driven atomic media, in which the group velocity is adiabatically reduced to zero. We discuss possible applications such as quantum state mem

Olivier Costa De Beauregard, Georges Lochak

Three predictions for additional tests in a Tonomura experiment: 1,2: The Fresnel frin-ges displayed outside and inside the geometric shadow of a toroidal magnet should subsist intact, the ones if the others are masked, and vice versa ; 3 : Placing the registering film just before the magnet and thus uncovering the entire fringe pattern should display the cu

G. F. Gribakin

The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the incoming positron with one of the molecular electrons. This mechanism dominates for atoms and small molecules. I show that its

A. V. Nikulov

One of the oldest science problems - possibility of the perpetuum mobile is discussed. The interest to this problem was provoke a result, published in J. Low Temp.Phys. 112, 227 (1998); cond-mat/9811148, which contradicts to the second law of thermodynamics. According to this result, the thermal fluctuations can induce a voltage with direct component in a in

A. Bianconi, G. Bonomi, E. Lodi Rizzini, L. Venturelli

We calculate, in a systematic way, the enhancement effect on antiproton-proton and antiproton-nucleus annihilation cross sections at low energy due to the initial state electrostatic interaction between the projectile and the target nucleus. This calculation is aimed at future comparisons between antineutron and antiproton annihilation rates on different tar

Bogdan Mihaila, Jochen H. Heisenberg

In this document we present our approach to the computation of three-body matrix elements, based on the Urbana family of three-nucleon potentials. The calculations refer only to the necessary matrix elements needed to include the three-nucleon interaction in the manner presented in nucl-th/9912023.

Bogdan Mihaila, Jochen H. Heisenberg

We continue the investigations of the $^{16}$O ground state using the coupled-cluster expansion [$\exp({\bf S})$] method with realistic nuclear interaction. In this stage of the project, we take into account the three nucleon interaction, and examine in some detail the definition of the internal Hamiltonian, thus trying to correct for the center-of-mass moti

V. Grassi, R. A. Leo, G. Soliani, P. Tempesta

We show that certain infinitesimal operators of the Lie-point symmetries of the incompressible 3D Navier-Stokes equations give rise to vortex solutions with different characteristics. This approach allows an algebraic classification of vortices and throws light on the alignment mechanism between the vorticity and the vortex stretching vector. The symmetry al

John Hempel

A Heegaard diagram for a 3-manifold M is a closed, oriented surface S together with a pair (X, Y) of compact 1-manifolds in S whose components serve as attaching curves for the 2-handles of the two sides of a Heegaard splitting for M. The diagram is positive if X and Y can be oriented so that the intersection number <X,Y>_p = +1 at each point p in their inte

R. F. Picken, P. A. Semiao

We give an introduction for the non-expert to TQFT (Topological Quantum Field Theory), focussing especially on its role in algebraic topology. We compare the Atiyah axioms for TQFT with the Eilenberg Steenrod axioms for homology, give a few simple examples of TQFTs, and discuss some other approaches that have been taken to defining TQFT. We then propose a ne

Alberto S. Cattaneo

The first part of this paper is a short review of the construction [dg-ga/9710001] of invariants of rational homology 3-spheres and knots in terms of configuration space integrals. The second part describes the relationship between the above construction and Kontsevich&#39;s proposal of removing one point from the rational homology sphere. Explicit formulae

Charles P. Boyer, Krzysztof Galicki

We show that every K-contact Einstein manifold is Sasakian-Einstein and discuss several corollaries of this result.

I. A. B. Strachan

The notion of a Frobenius submanifold - a submanifold of a Frobenius manifold which is itself a Frobenius manifold with respect to structures induced from the original manifold - is studied. Two dimensional submanifolds are particularly simple. More generally, sufficient conditions are given for a submanifold to be a so-called natural submanifold. These idea

Tien-Cuong Dinh

Nous demontrons qu&#39;une sous-variete reelle, compacte, orientee et lisse Γde dimension $2p-1\geq 3$ de CP^n est le bord d&#39;un sous-ensemble analytique s&#39;il existe une variete reelle $V\subset G(n-p+2,n+1)$ de codimension 1 satisfaisant les conditions suivantes pour tout $ν\in V$ 1. La reunion $\bigcup_{ν\in V} P^{n-p+1}_ν$ recouvre un ouvert dense

M. Leo, R. A. Leo, G. Soliani

We show that the use of the main characteristics of the circle map leads naturally to establish a few statements on primes and pseudoprimes. In this way a Fermat&#39;s theorem on primes and some interesting properties of pseudoprimes are obtained.

Ludvig Faddeev

An extension of Quantum Group is described. We propose to unite the quantum groups with parameter q and with parameter modularly dual to q.

G. Bimonte, G. Marmo, A. Stern

We construct a deformation of the quantum algebra Fun(T^*G) associated with Lie group G to the case where G is replaced by a quantum group G_q which has a bicovariant calculus. The deformation easily allows for the inclusion of the current algebra of left and right invariant one forms. We use it to examine a possible generalization of the Gauss law commutati

Rodolfo Russo, Claudio A. Scrucca

We study the world-volume effective action of stable non-BPS branes present in Type II theories compactified on K3. In particular, by exploiting the conformal description of these objects available in the orbifold limit, we argue that their world-volume effective theory can be chiral. The resulting anomalies are cancelled through the usual inflow mechanism p

G. Nardelli, M. Peloso

The partition function of a two dimensional Abelian gauge model reproducing magnetic vortices is discussed in the harmonic approximation. Classical solutions exhibit conformal invariance, that is broken by statistical fluctuations, apart from an exceptional case. The corresponding ``anomaly&#39;&#39; has been evaluated. Zero modes of the thermal fluctuation

A. Harindranath, L. Martinovic, J. P. Vary

We address problems associated with compactification near and on the light front. In perturbative scalar field theory we illustrate and clarify the relationships among three approaches: (1) quantization on a space-like surface close to a light front; (2) infinite momentum frame calculations; and (3) quantization on the light front. Our examples emphasize the

J. Evslin, M. B. Halpern, J. E. Wang

We apply the new orbifold duality transformations to discuss the special case of cyclic coset orbifolds in further detail. We focus in particular on the case of the interacting cyclic coset orbifolds, whose untwisted sectors are Z_λ(permutation)-invariant g/h coset constructions which are not λcopies of coset constructions. Because λcopies are not involved,

Hitoshi Yamamoto

We review recent measurements as well as phenomenological background of the semileptonic branching fraction of $b$ hadrons and number of charm produced per decay of $b$ hadrons.

Peter Arnold

A proper sequence of effective theories, corresponding to larger and larger distance scales, is crucial for analyzing real-time equilibrium physics in hot non-Abelian plasmas. For the study of color dynamics (by which I mean physics involving long wavelength gauge fluctuations), an important stepping stone in the sequence of effective theories is to have a g

Peter Arnold, Laurence G. Yaffe

The non-Abelian analog of electrical conductivity at high temperature has previously been known only at leading logarithmic order: that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling. We calculate the first sub-leading correction. This has immediate application to improving, to next-to-leading log order, both effective t

Peter Arnold, Laurence G. Yaffe

Many aspects of high-temperature gauge theories, such as the electroweak baryon number violation rate, color conductivity, and the hard gluon damping rate, have previously been understood only at leading logarithmic order (that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling). We discuss how to systematically go beyond le

Hoang Ngoc Long

In the framework of the minimal ${SU}(3)_C\otimes {SU}(3)_L \otimes {U}(1)_N$ model, the lepton-flavour-violating decay $π^+ \ra μ^- ν_μe^+ e^+ $ is calculated without directly invoking lepton mixing. The branching ratio for this rare pion decay mode is found to be much smaller than the current experimental upper limit. Dropping out anomalous interactions, t

N. J. Watson

The pinch technique (PT) is an algorithm for the rearrangement of contributions to conventional, gauge-dependent n-point functions in gauge theories to obtain a formulation of one-loop perturbation theory in terms of ``effective&#39;&#39; n-point functions which, principle among many other desirable properties, are individually entirely independent of the pa

Anna Kulesza, W. James Stirling

A complete description of W and Z boson production at high-energy colliders requires the resummation of large Sudakov logarithms which dominate the production at small transverse momentum. Currently there are two techniques for performing this resummation: impact parameter space and transverse momentum space. We argue that the latter can be formulated in a w

V. V. Andreev, M. N. Sergeenko

A model potential for two-particle relativistic systems is investigated in the framework of Poincare-invariant quantum mechanics (or relativistic Hamiltonian dynamics). The potential considered allows to reduce the main integro-differential equation of Poincare-invariant quantum mechanics to the equation analogous to the radial equation and have analytical s

John F. Donoghue

This talk describes some of the consequences for particle phenomenology of the hypothesis that the physical parameters may vary in different domains of the universe.

Valery A. Khoze, Torbjörn Sjöstrand

Heavy objects like the W, Z and t are short-lived compared with typical hadronization times. When pairs of such particles are produced, the subsequent hadronic decay systems may therefore become interconnected. We study such potential effects at Linear Collider energies.

V. V. Andreev, N. V. Maksimenko

In this work the electromagnetic radius and the polarizability of the mesons are obtained by use of the effective Lagrangians constructed on the one hand with taking into account of general principles of the relativistic quantum field theory and on the other hand with taking into account of the compound relativistic model meson representation. Also using a r

A. Pich

The pure leptonic or semileptonic character of tau decays makes them a good laboratory to test the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic $τ$ decay modes constitute an ideal tool for studying low--energy effects of the strong interactions in very clean conditions. New physics phenomena, such a

A. Dedes, M. Pospelov

Assuming that the axion mechanism of solving the strong CP problem does not exist and the vanishing of theta at tree level is achieved by some model-building means, we study the naturalness of having large CP-violating sources in the leptonic sector. We consider the radiative mechanisms which transfer a possibly large CP-violating phase in the leptonic secto

B. R. Webber

Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation of fragmentation functions, hadronization models, single-particle yields and spectra in Z decay, comparisons between quark and gluon jets, current and target frag

G. Altarelli

1. Why we do Believe in the Standard Model 2. Why we do not Believe in the Standard Model 2.1 Conceptual Problems 2.2 Hints from Experiment 2.2.1 Unification of Couplings 2.2.2 Dark Matter 2.2.3 Neutrino Masses 2.2.4 Baryogenesis 3. Status of the Search for the Higgs and for New Physics 4. Conclusion

A. Denner, S. Dittmaier, M. Roth, D. Wackeroth

RACOONWW is an event generator for e+e- --> WW --> 4fermions(+gamma) that includes full tree-level predictions for e+e- --> 4f and e+e- --> 4f+gamma as well as O(alpha) corrections to e+e- --> 4f in the so-called double-pole approximation. We briefly sketch the concept of the calculation on which this generator is based and present some numerical results.

N. Mathur, S. J. Dong, K. F. Liu, L. Mankiewicz

We calculate the quark orbital angular momentum of the nucleon from the quark energy-momentum tensor form factors on the lattice. The disconnected insertion is estimated stochastically which employs the $Z_2$ noise with an unbiased subtraction. This reduced the error by a factor of 4 with negligible overhead. The total quark contribution to the proton spin i

Oleg Lebedev, Will Loinaz, Tatsu Takeuchi

We analyze the one loop corrections to leptonic W and Z decays in an R-parity violating extension to the Minimal Supersymmetric Standard Model (MSSM). We find that lepton universality violation in the Z line-shape variables alone would strengthen the bounds on the magnitudes of the lambda&#39; couplings, but a global fit on all data leaves the bounds virtual

I. L. Bogolubsky, V. K. Mitrjushkin, M. Müller-Preussker, P. Peter

For the Lorentz gauge the influence of various Gribov gauge copies on the fermion propagator is investigated in quenched compact lattice QED. Within the Coulomb phase besides double Dirac sheets the zero-momentum modes of the gauge fields are shown to cause the propagator to deviate strongly from the perturbatively expected behaviour. The standard way to ext

T. Affolder

We present a measurement of the cross section for production of two or more jets as a function of dijet mass, based on an integrated luminosity of 86 pb^-1 collected with the Collider Detector at Fermilab. Our dijet mass spectrum is described within errors by next-to-leading order QCD predictions using CTEQ4HJ parton distributions, and is in good agreement w

Harry W. K. Cheung

A review of the latest experimental results on charm particle lifetimes is presented. The most significant update is that the D_s^+ lifetime is conclusively larger than the D^0 lifetime and signifies that W-exchange/W-annihilation contributions are large. Using new high statistics data on $D^+\to K^+π^+π^-$ together with the D_s^+ lifetime and some assumptio

2 collaboration

Using 3.07 ${pb}^{-1}$ of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process $\epm \to \pch$ have been selected. The energy dependence of the cross section agrees with the assumption of the $a_1(1260) π$ intermediate state which is dominant above 1 GeV. For the first time \fourpi events are observed at the $ρ$ meson en

Jorge L. Cervantes Cota

It is shown some exact solutions in the Brans-Dicke (BD) theory for a Bianchi V metric having the property of inflationary expansion, graceful exit, and asymptotic evolution to a Friedmann-Robertson-Walker (FRW) open model. It is remarkable that an inflationary behaviour can occur, even without a cosmological potential or constant. However, the horizon and f

Zhong Chao Wu

We study the quantum creation of black hole pairs in the (anti-)de Sitter space background. These black hole pairs in the Kerr-Newman family are created from constrained instantons. At the $WKB$ level, for the chargeless and nonrotating case, the relative creation probability is the exponential of (the negative of) the entropy of the universe. Also for the r

Eric Poisson

These notes provide two derivations of the Lorentz-Dirac equation. The first is patterned after Landau and Lifshitz and is based on the observation that the half-retarded minus half-advanced potential is entirely responsible for the radiation-reaction force. The second is patterned after Dirac, and is based upon considerations of energy-momentum conservation

L. Herrera, A. Di Prisco, D. Pavon

We comment on recently proposed dissipative inflationary models. It is shown that the strength of the inflationary expansion is related to a specific combination of thermodynamic variables which is known to measure the instability of self-gravitating dissipative systems.

J. Fernando Barbero G., Eduardo J. S. Villaseñor

We show that local diff-invariant free field theories in four spacetime dimensions do not have local degrees of freedom.

Mayeul Arminjon

A scalar, preferred-frame theory of gravitation is summarized. Space-time is endowed with both a flat metric and a curved, &#34;physical&#34; metric. Motion is governed by a natural extension of Newton&#39;s second law, which implies geodesic motion only for a static field. The theory predicts Schwarzschild&#39;s exterior metric in the spherical static situa

Tetsuya Shiromizu, Uchida Gen

We consider the force acting on a spinning charged test particle (probe particle) with the mass m and the charge q in slow rotating the Kerr-Newman-deSitter(KNdS) black hole with the mass M and the charge Q. We consider the case which the spin vector of the probe particle is parallel to the angular momentum vector of the KNdS space-time. We take account of t

S. Mishra, D. N. Tripathy

The quantum mechanical approach developed by us recently for the evolution of the universe is used to derive an alternative derivation connecting the temperature of the cosmic background radiation and the age of the universe which is found to be similar to the one obtained by Gamow long back. By assuming the age of the universe to be $\approx$ 20 billion yea

Michael E. Flatte, David E. Reynolds

Qualitative differences in the spectrum of a superconductor near magnetic impurity pairs with moments aligned parallel and antiparallel are derived. A proposal is made for a new, nonmagnetic scanning tunneling spectroscopy of magnetic impurity interactions based on these differences. Near parallel impurity pairs the mid-gap localized spin-polarized states as

N. Morozov, L. Krusin-Elbaum, T. Shibauchi, L. N. Bulaevskii

We report on the c-axis resistivity rho_c(H) in Bi_2Sr_2CaCu_2O_{8+δ} that peaks in quasi-static magnetic fields up to 60 T. By suppressing the Josephson part of the two-channel (Cooper pair/quasiparticle) conductivity σ_c (H), we find that the negative slope of ρ_c(H) above the peak is due to quasiparticle tunneling conductivity σ_q(H) across the CuO_2 laye

Michael E. Flatte, Jeff M. Byers

The behavior of spin diffusion in doped semiconductors is shown to be qualitatively different than in undoped (intrinsic) ones. Whereas a spin packet in an intrinsic semiconductor must be a multiple-band disturbance, involving inhomogeneous distributions of both electrons and holes, in a doped semiconductor a single-band disturbance is possible. For n-doped

EunJoo Thompson, G. Lawes, J. M. Parpia, R. O. Pohl

Internal friction and speed of sound of a-SiO(2) was measured above 6 mK using a torsional oscillator at 90 kHz, controlling for thermal decoupling, non-linear effects, and clamping losses. Strain amplitudes e(A) = 10^{-8} mark the transition between the linear and non-linear regime. In the linear regime, excellent agreement with the Tunneling Model was obse

Eric J. Walter, Steven P. Lewis, Andrew M. Rappe

We have calculated the adsorption energy of carbon monoxide on a monolayer of copper adsorbed on the (111) face of cubic zirconia. We investigate the structural parameters of three phases of bulk zirconia (cubic, tetragonal, and monoclinic) and find excellent agreement with experiment. We have also analyzed the structural relaxation of both the stoichiometri

Anna Chame, Sylvie Rousset, Hans P. Bonzel, Jacques Villain

Two kinds of configurations involving steps on surfaces are reviewed. The first one results from an initially planar vicinal surface, i.e. slightly deviating from a high-symmetry (001) or (111) orientation. In some cases, these surfaces separate into domains of different orientations by a mechanism which is very similar to phase separation in mixtures. The d

Alexei V. Tkachenko, Vachtang Putkaradze

We present a description of granular dynamics based on the idea of differentiation between fluid and solid components. First, we construct a model of completely fluidized phase. Then we discuss a shear surface motion on the boundary of the bulk solid phase, induced by a moving wall. Our results include the thickness dependence of the velocity of a developed

H. Schulz-Baldes, J. Kellendonk, Th. Richter

The edge Hall conductivity is shown to be an integer multiple of $e^2/h$ which is almost surely independent of the choice of the disordered configuration. Its equality to the bulk Hall conductivity given by the Kubo-Chern formula follows from K-theoretic arguments. This leads to quantization of the Hall conductance for any redistribution of the current in th

R. S. Ghaskadvi, Michael Dennin

We report on simulations of reversible random sequential adsorption of dimers on three different lattices: a one-dimensional lattice, a two-dimensional triangular lattice, and a two-dimensional triangular lattice with the nearest neighbors excluded. In addition to the adsorption of particles at a rate K+, we allow particles to leave the surface at a rate K-.

Cristiano De Michele, Dino Leporini

The rotational dynamics of a supercooled molecular liquid is investigated by a molecular-dynamics numerical study. We detect rotational jumps with a waiting-time distribution which is well fitted by a truncated power law. At lower temperatures the rotational correlation times are decoupled from the viscosity.

Cristiano De Michele, Dino Leporini

We study the transport and the relaxation properties of a molecular supercooled liquid by molecular-dynamics numerical simulations. The focus is on the translational motion. Jump motion is detected. At lower temperature the Stokes-Einstein law breaks down.

Yu. A. Krotov, I. M. Suslov

The Ginzburg sandwich is a superconducting film coated with a dielectric layer containing Bose-type exitations, i.e. exitons. Using spatially inhomogeneous Eliashberg equations in the local interaction limit, an exact result for the superconducting transition temperature of the Ginzburg sandwich has been obtained in the first order in a/L (where a is interat

V. A. Krupenin, D. E. Presnov, A. B. Zorin, J. Niemeyer

The low-frequency noise figures of single-electron transistors (electrometers) of traditional planar and new stacked geometry were compared. We observed a correlation between the charge noise and the contact area of the transistor island with a dielectric substrate in the set of Al transistors located on the same chip and having almost similar electric param

J. K. Freericks, R. Lemanski

The spinless Falicov-Kimball model is solved exactly in the limit of infinite-dimensions on both the hypercubic and Bethe lattices. The competition between segregation, which is present for large U, and charge-density-wave order, which is prevalent at moderate U, is examined in detail. We find a rich phase diagram which displays both of these phases. The mod

K. S. D. Beach, R. J. Gooding, F. Marsiglio

This short paper summarizes a calculational method for obtaining the dynamical properties of many-body theories formulated in terms of (unrenormalized) bare propagators (and more generally, in terms of meromorphic functions, or convolutions over meromorphic functions) to a very high accuracy. We demonstrate the method by applying it to a T-matrix theory of t

T. Hakobyan, D. Sedrakyan, A. Sedrakyan, I. Gomez

Electron and phonon states in two different models of intentionally disordered superlattices are studied analytically as well as numerically. The localization length is calculated exactly and we found that it diverges for particular energies or frequencies, suggesting the existence of delocalized states for both electrons and phonons. Numerical calculations

M. Alouani, J. M. Wills

The most popular electronic structure method, the linear muffin-tin orbital method (LMTO), in its full-potential (FP) and relativistic forms has been extended to calculate the spectroscopic properties of materials form first principles, i.e, optical spectra, x-ray magnetic circular dichroism (XMCD) and magneto-optical kerr effect (MOKE). The paper describes

John M Wills, Olle Eriksson, Mebarek Alouani, David L. Price

The essential features of a full potential electronic structure method using Linear Muffin-Tin Orbitals (LMTOs) are presented. The electron density and potential in the this method are represented with no inherent geometrical approximation. This method allows the calculation of total energies and forces with arbitrary accuracy while sacrificing much of the e