September 1997 arXiv papers

Holger Lyre

In his last article "Against `Measurement'" J. S. Bell sums up his well known critique of the problem of explaining the measurement process within the framework of quantum theory. In this article I will discuss the measurement process by analysing the concept of measurement from the epistemological point of view and I will argue against Bell that

John Brodie

We construct two dimensional gauge theories with $N= (4,4)$ supersymmetry from branes of type IIA string theory. Quantum effects in the two dimensional gauge theory are analyzed by embedding the IIA brane construction into M-theory. We find that the Coulomb branch of one theory and the Higgs branch of a mirror theory become equivalent at strong coupling. A r

Joseph C. Varilly

This is the introduction and bibliography for lecture notes of a course given at the Summer School on Noncommutative Geometry and Applications, sponsored by the European Mathematical Society, at Monsaraz and Lisboa, Portugal, September 1-10, 1997. In the published version, an epilogue of recent developments and many new references from 1998-2006 have been ad

Paul M. N. Feehan, Thomas G. Leness

Using quantum field-theoretic arguments, Witten has established a relation between the Donaldson and Seiberg-Witten invariants of smooth four-manifolds. In this survey article, we describe the program to prove this relation using a moduli space of PU(2) = SO(3) monopoles as a cobordism between the Donaldson moduli space of anti-self-dual SO(3) connections an

Alan Weinstein, Ping Xu

We show that the Hochschild cohomology of the algebra obtained by formal deformation quantization on a symplectic manifold is isomorphic to the formal series with coefficients in the de Rham cohomology of the manifold. The cohomology class obtained by differentiating the star-product with respect to the deformation parameter is seen to be closely related to

Benjamin Schumacher, Michael D. Westmoreland

We derive a simple relation between a quantum channel's capacity to convey coherent (quantum) information and its usefulness for quantum cryptography.

Jens Hoppe

For the SU(N) invariant supersymmetric matrix model related to membranes in 11 space-time dimensions, the general (bosonic) solution to the equations $Q_β^\dagger Ψ=0$ ($Q_βΨ=0$) is determined.

John McDonald

The Next to Minimal Supersymmetric Standard Model (NMSSM), proposed as a solution of the mu problem of the Minimal Supersymmetric Standard Model, has a discrete Z_{3} symmetry which is spontaneously broken at the electroweak phase transition, resulting in a cosmological domain wall problem. In most cases this domain wall problem cannot be solved by explicit

Wolfgang Bock, Maarten Golterman, Yigal Shamir

We study a concrete lattice regularization of a U(1) chiral gauge theory. We use Wilson fermions, and include a Lorentz gauge-fixing term and a gauge-boson mass counterterm. For a reduced version of the model, in which the gauge fields are constrained to the trivial orbit, we show that there are no species doublers, and that the fermion spectrum contains onl

G. K. Leontaris, N. D. Tracas

We derive the scalar mass matrices in effective supergravity models augmented by a $U(1)_F$ family symmetry. Simple relations between $U(1)_F$ charges and modular weights of the superfields are derived and used to express the matrices with a minimum number of parameters. The model predicts a branching ratio for the $μ\to eγ$ process close to the present expe

A. L. Kataev, A. V. Kotikov, G. Parente, A. V. Sidorov

The next-to-next-to-leading order (NNLO) QCD analysis of the revised experimental data of the CCFR collaboration for the $xF_3$ structure function of the deep-inelastic scattering of neutrinos and antinuetrinos on the nucleons is made by means of the Jacobi polynomial expansion technique. The NNLO values of the QCD coupling constant are determined both witho

A. Ali

We discuss some selected topics in rare B decays in the context of the standard model and compare theoretical estimates with available data. Salient features of the perturbative-QCD and power corrections in the decay rate for $B \to X_s + \gamma$ are reviewed and this framework is used to determine the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $| V_{ts}

N. Pavloff, C. Schmit

We study the thermally activated oscillations, or capillary waves, of a neutral metal cluster within the liquid drop model. These deformations correspond to a surface roughness which we characterize by a single parameter $Δ$. We derive a simple analytic approximate expression determining $Δ$ as a function of temperature and cluster size. We then estimate the

Xuemin Jin, Manuel Malheiro

We evaluate the nucleon sigma term and in-medium quark condensate in the modified quark-meson coupling model which features a density-dependent bag constant. We obtain a nucleon sigma term consistent with its empirical value, which requires a significant reduction of the bag constant in the nuclear medium similar to those found in the previous works. The res

Matthias Lutz

An effective low energy Lagrangian density is applied to nuclear $K^-$-dynamics. The free parameters, local s-wave couplings and SU(3)-symmetry constrained range terms are adjusted to describe elastic and inelastic $K^-$-nucleon scattering data. The propagation and decay of the $Λ(1405)$-resonance and the $Λ(1405)$-nucleon hole state is studied self consiste

Jan de Gier, Bernard Nienhuis

A random tiling of rectangles and triangles displaying a decagonal phase is solved by Bethe Ansatz. Analogously to the solutions of the dodecagonal square triangle and the octagonal rectangle triangle tiling an exact expression for the maximum of the entropy is found.

Ashoke Sen

The Hamiltonian describing Matrix theory on T^n is identified with the Hamiltonian describing the dynamics of D0-branes on T^n in an appropriate weak coupling limit for all n up to 5. New subtleties arise in taking this weak coupling limit for n=6, since the transverse size of the D0 brane system blows up in this limit. This can be attributed to the appearan

Hiroaki Kusunose

Ground-state properties are examined for an extended two-channel Kondo model where the Hilbert space of the localized states is extended to include a singlet state in addition to the doublet states. By means of zero-th order variational wavefunctions with different symmetries, which are associated with the non-Fermi-liquid and the Fermi-liquid ground states,

C. Anastopoulos, A. Zoupas

We employ the influence functional technique to trace out the photonic contribution from full quantum electrodynamics. The reduced density matrix propagator for the spinor field is then constructed. We discuss the role of time-dependent renormalization in the propagator and focus on the possibility of obtaining dynamically induced superselection rules. Final

M. Bastero-Gil, S. F. King

We propose a model of inflation based on a simple variant of the NMSSM, called $ϕ$NMSSM, where the additional singlet $ϕ$ plays the role of the inflaton in hybrid (or inverted hybrid) type models. As in the original NMSSM, the $ϕ$NMSSM solves the $μ$ problem of the MSSM via the VEV of a gauge singlet $N$, but unlike the NMSSM does not suffer from domain wall

Jens U. Noeckel, Klaus Richter

The linear response conductance coefficients are calculated in the scattering approach at finite frequency, damping and magnetic field for a microstructure in which the reservoirs are modeled as quantum wire leads of infinite length but finite width. Independently of frequency, inelastic scattering causes subbands with large group velocity to contribute more

Jae-Kwon Kim, Matthias Troyer

We present thermodynamic measurements of various physical observables of the two dimensional S=1/2 isotropic quantum Heisenberg antiferromagnet on a square lattice, obtained by quantum Monte Carlo. In particular we have been able to measure the infinite volume limit of the uniform susceptibility up to the inverse temperature beta=40, the analysis of which re

C. Fuchs, T. Waindzoch, Amand Faessler, D. S. Kosov

We investigate the momentum dependence of the nucleon self-energy in nuclear matter. We apply the relativistic Brueckner-Hartree-Fock approach and adopt the Bonn A potential. A strong momentum dependence of the scalar and vector self-energy components can be observed when a commonly used pseudo-vector choice for the covariant representation of the T-matrix i

Keshav Dasgupta, Sunil Mukhi

We examine some six-dimensional orientifold models with $N = 1$ supersymmetry, which can be realised as intersecting 7-branes and 7-planes. These models are studied in the light of recent work showing that orientifold planes carry anomalous gravitational couplings on their world-volume. We show that gravitational anomalies can be locally cancelled by these n

A. I. Davydychev, R. Delbourgo

A direct link between a one-loop N-point Feynman diagram and a geometrical representation based on the N-dimensional simplex is established by relating the Feynman parametric representations to the integrals over contents of (N-1)-dimensional simplices in non-Euclidean geometry of constant curvature. In particular, the four-point function in four dimensions

P. Ao

Analogous to Peierls' arguments for the `anomalous' Hall in metals I demonstrate that the Hall anomaly in the mixed state of superconductors, the sign change of the Hall resistivity, is a property of a vortex many-body correlation, and show that the anomaly is due to the competition between vortex vacancies and interstitials. Within this vortex many-

A. V. Shytov, P. A. Lee, L. S. Levitov

We discuss localization of quasiparticles in an extended NS structure in the situation when the reflection from the NS interface is mostly of Andreev kind. The localization of quasiparticle states arises due to trajectory retracing caused by Andreev reflection. This effect is semiclassical in the sense that in the classical limit the states become fully loca

A. Barbieri

The general solutin to the constraints that define relativistic spin networks vertices is given and their relations with 3-dimensional quantum tetrahedra is dicussed. An alternative way to handle the constraints is also presented.

Yuji Kodama

We present a model of optical communication system for high-bit-rate data transmission in the nonreturn-to-zero (NRZ) format over transoceanic distance. The system operates in a small group velocity dispersion regime, and the model equation is given by the Whitham equations describing the slow modulation of multi-phase wavetrains of the (defocusing) nonlinea

G. Marmo, G. Vilasi, A. Vinogradov

N-Lie algebra structures on smooth function algebras given by means of multi-differential operators, are studied. Necessary and sufficient conditions for the sum and the wedge product of two $n$-Poisson sructures to be again a multi-Poisson are found. It is proven that the canonical $n$-vector on the dual of an n-Lie algebra g is n-Poisson iff dim(g) are not

Bertrand Le Roy

Using colored superanalysis and epsilon-Lie superalgebras, we build the minimal Poincare superalgebra in the case of the Z_n^3-grading. We then build a representation of this algebra, and the corresponding Poincare supergroup.

Avinash Khare, Bhabani Prasad Mandal

We consider two quasi-exactly solvable problems in one dimension for which the Schrödinger equation can be converted to Heun's equation. We show that in neither case the Bender-Dunne polynomials form an orthogonal set. Using the anti-isopectral transformation we also discover a new quasi-exactly solvable problem and show that even in this case the polyno

Gerhard Hummer, Lawrence R. Pratt, Angel E. Garcia

Free energies of ionic solvation calculated from computer simulations exhibit a strong system size dependence. We perform a finite-size analysis based on a dielectric-continuum model with periodic boundary conditions. That analysis results in an estimate of the Born ion size. Remarkably, the finite-size correction applies to systems with only eight water mol

R. Irsigler, R. Geppert, R. Goeppert, M. Hornung

Full size single-sided GaAs microstrip detectors with integrated coupling capacitors and bias resistors have been fabricated on 3'' substrate wafers. PECVD deposited SiO_2 and SiO_2/Si_3N_4 layers were used to provide coupling capacitaces of 32.5 pF/cm and 61.6 pF/cm, respectively. The resistors are made of sputtered CERMET using simple lift of techn

Peter Filip

Results of the computer simulation of dilepton production from the expanding pion gas created in ultrarelativistic Pb+Pb 160 GeV/n collisions are presented. Finite size of the expanding pion gas influences invariant mass spectrum of dileptons. Sensitivity of the shape of dilepton mass spectrum to the initial stage of the pion gas is discussed. Second order a

L. P. Kaptari, B. Kaempfer S. M. Dorkin, S. S. Semikh

The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, like tensor analyzing power and polarization transfer etc., are investigated in explicit form.

J. J. van Leeuwe, H. P. Blok, J. F. J. van den Brand, H. J. Bulten

The $(e,e'p)$ reaction on $^{4}{He}$ nuclei was studied in kinematics designed to emphasize effects of nuclear short-range correlations. The measured cross sections display a peak in the kinematical regions where two-nucleon processes are expected to dominate. Theoretical models incorporating short-range correlation effects agree reasonably with the data

Siqi Fu, Bun Wong

In this paper, we prove that if D is a simply-connected domain in C^2 with generic piecewise smooth Levi-flat boundary and non-compact automorphism group, then D is biholomorphic to the bidisc. The proof is based on a careful analysis of invariant measures.

I. V. Kanatchikov

Canonical structure of the space-time symmetric analogue of the Hamiltonian formalism in field theory based on the De Donder-Weyl (DW) theory is studied. In $n$ space-time dimensions the set of $n$ polymomenta is associated to the space-time derivatives of field variables. The polysymplectic $(n+1)$-form generalizes the simplectic form and gives rise to a ma

Stephan Melosch, Hermann Nicolai

A set of new canonical variables for $d=11$ supergravity is proposed which renders the supersymmetry variations and the supersymmetry constraint polynomial. The construction is based on the $SO(1,2)\times SO(16)$ invariant reformulation of $d=11$ supergravity given in previous work, and has some similarities with Ashtekar's reformulation of Einstein'

Viktoria Malyshenko, Domingo Marin Ricoy

We investigate multidimensional gravity with the Gauss-Bonnet term and with torsion on the space of extra dimensions chosen to be the group manifold of a simple Lie group. We take the Robertson-Walker ansatz for the 4-dimensional space-time and study the potential of a dilaton and torsion fields. It is shown that for certain values of the parameters of the i

Edi Halyo

We calculate the entropy of six dimensional Schwarzschild black holes in matrix theory. We use the description of the matrix model on $T^5$ as the world-volume theory of NS five-branes and show that the black hole entropy is reproduced by noncritical closed strings with fractional tension living on the five-brane.

Raphael Bousso, Stephen Hawking

We study the quantum evolution of black holes immersed in a de Sitter background space. For black holes whose size is comparable to that of the cosmological horizon, this process differs significantly from the evaporation of asymptotically flat black holes. Our model includes the one-loop effective action in the s-wave and large N approximation. Black holes

Dieter Lust

We review the duality between heterotic and F--theory string vacua with N=1 space-time supersymmetry in eight, six and four dimensions. In particular, we discuss two chains of four-dimensional F--theory/heterotic dual string pairs, where F--theory is compactified on certain elliptic Calabi-Yau fourfolds, and the dual heterotic vacua are given by compactifica

Richard Battye, Paul Sutcliffe

Recently it has been found that the structure of Skyrmions has a close analogy to that of fullerene shells in carbon chemistry. In this letter we show that this analogy continues further, by presenting a Skyrme field that describes a lattice of Skyrmions with hexagonal symmetry. This configuration, a novel `domain wall' in the Skyrme model, has low energ

Kazuo Fujikawa, Hiroshi Suzuki

It is pointed out that there exists an interesting strong and weak duality in the Landau-Zener-Stueckelberg potential curve crossing. A reliable perturbation theory can thus be formulated in the both limits of weak and strong interactions. It is shown that main characteristics of the potential crossing phenomena such as the Landau-Zener formula including its

Sabbir Rahman

The set of string vertices is extended to include moduli spaces with genus and numbers of ordinary and special punctures ranging over all integral values $g,n,\bar n\geq0$. It is argued that both the string background and the B-V delta operator should be associated with the vertex $\B^0_{0,1}$ corresponding to the once-punctured sphere. This leads naturally

B. Dutta, S. Nandi

We propose a new scenario in which the dominant signal for supersymmetry at the Tevatron are the events having two or three $τ$ leptons with high $p_T$ accompanied by large missing transverse energy. This signal is very different from the multijet or multileptons (involving $e$ and/or $μ$ only) or the photonic signals that have been extensively investigated

X. Q. Li, B. S. Zou

We study the direct CP violation induced by inelastic final state interaction (FSI) rescattering in $D\toππ$ modes, and find that the resultant CP asymmetry is about $10^{-4}$ which is larger than $ε'$ in the K-system. Our estimation is based on well-established theories and experiment measured data, so there are almost no free parameters except the weak

K. Iordanidis, D. Zeppenfeld

The discovery of a heavy Higgs boson with mass up to m_H = 1 TeV at the CERN LHC is possible in the H--> W^+W^- --> l nu jj decay mode. The weak boson scattering signal and backgrounds from t\bar tjj and from W+jets production are analyzed with parton level Monte Carlo programs which are built on full tree level amplitudes for all subprocesses. The use of do

J. -F. Grivaz

Searches for supersymmetric particles performed at LEP 1 and LEP 2 are reviewed. Using the MSSM with R-parity conservation as a reference model, the various analyses are briefly described, and the results are presented in terms of mass and coupling limits. Further implications of these results are discussed, including lower limits on the mass of a neutralino

J. -F. Grivaz

A brief summary of the experimental results presented at the conference is given.

Stefano Catani

I briefly summarize some general features of soft-gluon contribution to inclusive cross-sections. The discussion includes the issue of soft-gluon singularities in infrared- and collinear-safe observables. All-order resummation and the ensuing varieties of QCD predictions are illustrated.

R. A. Alanakyan

By model independent way scalar and pseudoscalar neutral Higgs boson production with photon in the tree process $μ^+μ^- \to H^0 γ$ are considered.For the Standard Model and Minimal Supersymmetric Standard Model cases numerical estimates are obtained.The model independent flavour changing Higgs bosons production in the tree processes $e^+e^-,μ^+e^- \to H^0_{f

Sheldon Stone

BTeV and LHC-B are experiments being proposed to study $b$ and $c$ quark decays in hadron-hadron collisions with the aims to look for new phenomena beyond the Standard Model and to measure Standard Model parameters including CKM elements and decay constants. The physics goals, required detection techniques and simulations will be discussed.

Marvin Weinstein

The COntractor REnormalization group method (CORE), originally developed for application to lattice gauge theories, is very well adapted the study of spin systems and systems with fermions. As an warmup exercise for studying Hubbard models this method is applied to spin-1/2 and spin-1 anti-ferromagnets in one space dimension in order to see if it is able to

S. J. Dong, T. Draper, W. C. Kuo, K. F. Liu

We describe a lattice calculation of the matrix elements relevant for glueball production in $J / ψ$ radiative decays. The techniques for such a calculation on anisotropic lattices with an improved action are outlined. We present preliminary results showing the efficacy of the computational method.

Urs M. Heller

We discuss the Schrödinger functional in lattice QCD with staggered fermions and relate it, in the classical continuum limit, to the Schrödinger functional regularized with Wilson fermions. We compute the strong coupling constant defined via the Schrödinger functional with staggered fermions at one loop and show that it agrees with the continuum running coup

C. Gutsfeld, H. A. Kastrup, K. Stergios, J. Westphalen

We discuss the possibility of extracting phase shifts from finite volume energies for meson-meson scattering, where the mesons are fermion-antifermion bound states of the massive Schwinger model with SU(2) flavour symmetry. The existence of analytical strong coupling predictions for the mass spectrum and for the scattering phases makes it possible to test th

B. Beinlich, A. Bicker, F. Karsch, E. Laermann

We introduce a class of improved actions for staggered fermions which to O(p^4) and O(p^6), respectively, lead to rotationally invariant propagators. We discuss the resulting reduction of flavour symmetry breaking in the meson spectrum and comment on the improvement in the calculation of thermodynamic observables.

Markus Feurstein, Harald Markum, Stefan Thurner

In the last years it turned out that instantons and monopoles have a certain local correlation in four-dimensional QCD. It was demonstrated by several groups independently and by different methods that at the locations of instantons also monopoles in the maximal abelian projection can be found with enhanced probability. Further we observed such nontrivial co

Markus Feurstein, Harald Markum, Stefan Thurner

We perform a mutual analysis of the topological and chiral vacuum structure of four-dimensional QCD on the lattice at finite temperature. We demonstrate that at the places where instantons are present, amplified production of quark condensate takes place. It turns out for full QCD that the clusters of nontrivial chiral condensate have a size of about 0.4 fm

Markus Feurstein, Harald Markum, Stefan Thurner

We perform an analysis of the topological and chiral vacuum structure of four-dimensional QCD on the lattice at finite temperature. From correlation functions we show the existence of local correlations between the topological charge density and the quark condensate on gauge average. We comment on sizes of clusters of nontrivial chiral condensate and of inst

H. R. Fiebig, H. Markum, A. Mihaly, K. Rabitsch

We extend our calculations with the second-order tree-level and tadpole improved next-nearest-neighbor action to meson-meson systems. Correlation matrices built from interpolating fields representing two pseudoscalar mesons (pion-pion) with relative momenta p are diagonalized, and the mass spectrum is extracted. Link variable fuzzing and operator smearing at

M. Talevi

We present the first results obtained by the UKQCD Collaboration using a non-perturbatively $O(a)$ improved Wilson quark action with two degenerate dynamical flavours.

H. R. Fiebig, H. Markum, A. Mihaly, K. Rabitsch

We extend our investigation of heavy-light meson-meson interactions to a system consisting of a heavy-light meson and the corresponding antiparticle. An effective potential is obtained from meson-antimeson Green-functions computed in a quenched simulation with staggered fermions. Comparisons with a simulation using an $O(a^2)$ tree-level and tadpole improved

R. W. Kuhne

Recently, we suggested a model of magnetic monopoles (hep-ph/9708394). Here we will propose a tabletop experiment to test this model. The verification of the predicted effect would have far-reaching consequences.

A. Kharchilava

One of the main motivations of experiments at the LHC is to search for SUSY particles. The talk is based on recent analyses, performed by CMS Collaboration, within the framework of the Supergravity motivated minimal SUSY extension of the Standard Model. The emphasis is put on leptonic channels. The strategies for obtaining experimental signatures for strongl

L. Andersson, G. J. Galloway, R. Howard

Let $(M,g)$ be a time oriented Lorentzian manifold and $d$ the Lorentzian distance on $M$. The function $τ(q):=\sup_{p< q} d(p,q)$ is the cosmological time function of $M$, where as usual $p< q$ means that $p$ is in the causal past of $q$. This function is called regular iff $τ(q) < \infty$ for all $q$ and also $τ\to 0$ along every past inextendible causal c

V. N. Pervushin, V. I Smirichinski

The unification of the Einstein theory of gravity with a conformal invariant version of the standard model for electroweak interaction without the Higgs potential is considered. In this theory, a module of the Higgs field is absorbed by the scale factor component of metric so that the evolution of the Universe and the elementary particle masses have one and

The Binary Black Hole Grand Challenge Alliance, :, A. M. Abrahams, L. Rezzolla

We present a method for extracting gravitational radiation from a three-dimensional numerical relativity simulation and, using the extracted data, to provide outer boundary conditions. The method treats dynamical gravitational variables as nonspherical perturbations of Schwarzschild geometry. We discuss a code which implements this method and present results

O. Sarbach, N. Straumann, M. S. Volkov

We study the interior structure of the Einstein-Yang-Mills-Dilaton black holes as a function of the dilaton coupling constant $γ\in [0,1]$. For $γ\neq 0$ the solutions have no internal Cauchy horizons and the field amplitudes follow a power law behavior near the singularity. As $γ$ decreases, the solutions develop more and more oscillation cycles in the inte

P. V. Moniz

We study the quantum behaviour of Reissner-Nordström (RN) black-holes interacting with a complex scalar field. A Maxwell field is also present. Our analysis is based on M. Pollock&#39;s method and is characterized by solving a Wheeler-DeWitt equation in the proximity of an apparent horizon of the RN space-time. Subsequently, we obtain a wave-function $Ψ_{RN}

Palle E. T. Jorgensen, Steen Pedersen

We consider self-similar measures $μ$ with support in the interval $0\leq x\leq 1$ which have the analytic functions $\left\{e^{i2πnx}:n=0,1,2,... \right\} $ span a dense subspace in $L^{2}(μ) $. Depending on the fractal dimension of $μ$, we identify subsets $P\subset \mathbb{N}_{0}=\{0,1,2,... \} $ such that the functions $\{e_{n}:n\in P\} $ form an orthono

S-K. Chin, M. A. Moore

We investigate the effect of thermal fluctuations on the (mean-field) Abrikosov phase. The lower critical dimension of the superconducting phase is three, indicating the absence of the Abrikosov phase for dimensions d<3. Within the d=3 vortex liquid, the phase correlation length along the magnetic field direction grows exponentially rapidly as the temperatur

Steven P. Lewis, M. V. Pykhtin, E. J. Mele, Andrew M. Rappe

An analytical theory is presented for the damping of low-frequency adsorbate vibrations via resonant coupling to the substrate phonons. The system is treated classically, with the substrate modeled as a semi-infinite elastic continuum and the adsorbate overlayer modeled as an array of point masses connected to the surface by harmonic springs. The theory prov

J. K. Bhattacharjee, D. Thirumalai, J. D. Bryngelson

The distribution function of the end-to-end distance of a semiflexible polymer, G(R;L) (where R denotes the end-to-end distance and L the contour length), is calculated using a meanfield-like approach. The theory yields an extremely simple expression for G(R;L) which is in excellent agreement with Monte Carlo simulations. The second and fourth moments of G(R

Andrea Huck, F. W. J. Hekking, Bernhard Kramer

We study the subgap transport properties of a small capacitance normal metal-superconductor tunnel junction coupled to an external electromagnetic environment. Mesoscopic interference between the electrons in the normal metal strongly enhances the subgap conductance with decreasing bias voltage. On the other hand, quantum fluctuations of the environment dest

Ophelia K. C. Tsui, S. G. J. Mochrie, L. E. Berman

We report a statistical analysis of the static speckle produced by illuminating a disordered aerogel sample by a nominally coherent x-ray beam at wiggler beamline X25 at the National Synchrotron Light Source. The results of the analysis allow us to determine that the coherence delivered to the X25 hutch is within 35% of what is expected. The rate of coherent

Stefan Kettemann

The composite fermion perspective is used, to study the flux dependence of thermodynamic properties of an annulus in the fractional quantum hall state at odd inverse filling factor. It is shown that $ϕ_0$- periodicity is restored, if there is tunneling of composite fermions between the edges of the annulus. In addition, the result for the finite magnitude of

Angsula Ghosh, Sadhan K. Adhikari

The solutions of a renormalized BCS equation are studied in three space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model yields a small coherence length $ξ$ and a large critical temperature, $T_c$, appropriate for some high-$T_c$ materials. The

A. Karlhede, K. Lejnell

The sharp ν=1 quantum Hall edge present for hard confinement is shown to have two modes that go soft as the confining potential softens. This signals a second order transition to a reconstructed edge that is either a depolarized spin-texture edge or a polarized charge density wave edge.

F. Wagner, Th. Laloyaux, M. Scheffler

In ab initio calculations of electronic structures, total energies, and forces, it is convenient and often even necessary to employ a broadening of the occupation numbers. If done carefully, this improves the accuracy of the calculated electron densities and total energies and stabilizes the convergence of the iterative approach towards self-consistency. How

W. Fettes, I. Morgenstern, T. Husslein

We present a new parallel algorithm for the exact diagonalization of the $t-t&#39;$-Hubbard model with the Lanczos-method. By invoking a new scheme of labeling the states we were able to obtain a speedup of up to four on 16 nodes of an IBM SP2 for the calculation of the ground state energy and an almost linear speedup for the calculation of the correlation f

Naoto Nagaosa, Shuichi Murakami, Hyun Cheol Lee

The interplay between the electron repulsion $U$ and the Jahn-Teller electron-phonon interation $E_{LR}$ is studied with a large $d$ model for the ferromagnetic state of the manganese oxides. These two interactions collaborate to induce the local isospin (orbital) moments and reduce the bandwidth $B$. Especially the retardation effect of the Jahn-Teller phon

Ewa Gudowska-Nowak, Gabor Papp, Juergen Brickmann

We discuss the effective donor/acceptor coupling for a bridged electron transfer system with a site-diagonal disorder of bridge energies. The average spectral properties of the system are discussed by using the Wegner model (Anderson&#39;s type tight-binding Hamiltonian (TBH))for the electronic part of the problem. Spectral properties of the system are discu

Michael W. Deem, Joel Bader

In this manuscript, we describe a new configurational bias Monte Carlo technique for the simulation of peptides. We focus on the biologically relevant cases of linear and cyclic peptides. Our approach leads to an efficient, Boltzmann-weighted sampling of the torsional degrees of freedom in these biological molecules, a feat not possible with previous Monte C

Rava da Silveira

In their letter, Andersen, Sornette, and Leung [Phys. Rev. Lett. 78, 2140 (1997)] describe possible behaviors for rupture in disordered media, based on the mean field-like democratic fiber bundle model. In this model, fibers are pulled with a force which is distributed uniformly. A fiber breaks if the stress on it exceeds a threshold chosen from a probabilit

Siegfried Grossmann, Sascha Hilgenfeldt, Detlef Lohse, Michael Zomack

The sound radiation of 3 MHz acoustically driven air bubbles in liquid is analysed with respect to possible applications in second harmonic ultrasound diagnostics devices, which have recently come into clinical use. In the forcing pressure amplitude P_a = 1-10 atm and ambient radius R_0 = 0.5-5 μm parameter domain a narrow regime around the resonance radius

Valentin V. Sokolov, B. Alex Brown, Vladimir Zelevinsky

We define correlational (von Neumann) entropy for an individual quantum state of a system whose time-independent hamiltonian contains random parameters and is treated as a member of a statistical ensemble. This entropy is representation independent and can be calculated as a trace functional of the density matrix which describes the system in its interaction

R. P. J. Tilanus, W. B. Burton

We present an exploratory survey of the central regions of the nearby spiral galaxies Dwingeloo 1 and Dwingeloo 2 made in the CO J=2->1 line at 230GHz using the James Clerk Maxwell Telescope. In Dwingeloo 1, which is probably the nearest grand-design barred spiral, the CO emission was sampled along a cross with its major axis aligned with the bar. The CO emi

S. D. Bloom, D. J. Thompson, R. C. Hartman, C. von Montigny

We have begun to examine the EGRET database for short term variations in the fluxes of blazars and unidentified sources at high Galactic latitude. We find that several AGN show previously unreported variability. Such variations are consistent with inverse Compton scattering processes in a shock propagating through a relativistic jet.

B. C. Matthews, B. J. Wallace, A. R. Taylor

Multi-frequency analysis has revealed the presence of a new supernova remnant, G55.0+0.3, in the Galactic plane. A kinematic distance of 14 kpc has been measured from HI spectral line data. The faint, clumpy half-shell is non-thermal and has a physical radius of 70 pc. Using an evolutionary model, the age of the remnant is estimated to be on the order of one

David H. Weinberg, Lars Hernquist, Neal Katz, Rupert Croft

Lyman-alpha forest lines in QSO spectra have typical widths of 20-50 km/s. Low column density absorbers in cosmological simulations are large, diffuse structures, and the Hubble flow across the spatially extended absorber is usually the dominant contribution to the width of its associated absorption line. Thermal broadening is unimportant over most of the sp

Rupert Croft

In gravitational instability models, there is a close relationship between most Lyman-alpha absorption and the matter density along the line of sight. Croft et al. (1997) have shown that it is possible to use this relationship with some additional assumptions (such as Gaussianity of the initial density) to recover the power spectrum of mass fluctuations, P(k

W. H. Lee, W. Kluzniak

Angular momentum loss via the emission of gravitational waves must eventually drive compact binaries containing black holes and/or neutron stars to coalesce. The resulting events are primary candidate sources for detectors such as VIRGO and LIGO. We present calculations of gravitational radiation waveforms and luminosities for the coalescence of a black hole

Re&#39;em Sari

The detection of delayed emission in X-ray, optical and radio wave length, ``afterglow&#39;&#39;, following a gamma-ray burst can be described by the emission of a relativistic shell decelerating upon collision with the ISM. We show that the observed radiation surface have well defined bright edges. We derive an explicit expression for the size as a function

H. M. P. Couchman

Cosmic structure simulations have improved enormously over the past decade, both in terms of the resolution which can be achieved, and with the addition of hydrodynamic and other techniques to formerly purely gravitational methods. This is an informal, and perhaps idiosyncratic, overview of the state and progress of cosmological simulations over this period.

F. Durret, P. Felenbok, C. Lobo, E. Slezak

We present a catalogue of velocities for 551 galaxies (and give the coordinates of 39 stars misclassified as galaxies in our photometric plate catalogue) in a region covering about 100&#39;$\times$100&#39; (0.94$\times$0.94 Mpc for an average redshift of 0.0555, assuming H$_\circ$=50 km s$^{-1}$ Mpc$^{-1}$) in the direction of the rich cluster Abell 85. This

Marina Gibilisco

In this work I study the polarization of the Cosmic Microwave Background (CMB) induced by a cosmological background of gravitational waves (here GWs) and I discuss the enhancement effect of a possible late and fast reionization of the Universe, caused by the Hawking evaporation of primordial black holes and happening at a redshift $z\sim 20÷30$. Then, I solv