September 1999 arXiv papers — page 23

Claude de Calan, Flavio S. Nogueira

The gauge dependence of the renormalization group functions of the Ginzburg-Landau model is investigated. The analysis is done by means of the Ward-Takahashi identities. After defining the local superconducting order parameter, it is shown that its exponent $β$ is in fact gauge independent. This happens because in $d=3$ the Landau gauge is the only gauge hav

H. C. Kao, B. Rosenstein, J. C. Lee

Consistent perturbation theory for thermodynamical quantities in strongly type II superconductors in magnetic field at low temperatures is developed. It is complementary to the existing expansion valid at high temperatures. Magnetization and specific heat are calculated to two loop order and compare well with existing Monte Carlo simulations, other theories

J. P. Wallington, James F. Annett

In this work we use functional integral techniques to examine the nearest neighbour attractive Hubbard model on a quasi-2D lattice. It is a simple phenomenological model for the high-Tc cuprates that allows both extended (non-local) s- and d-wave singlet superconductivity as well as mixed symmetry states. The Hartree-Gor'kov mean field theory of the mode

Sunetra Giridhar, David L. Lambert, Guillermo Gonzalez

Abundance analyses are presented and discussed for eight RV Tauri variables. The RV B star UY Ara shows the abundance anomalies seen in other RV B stars, namely elements that condense into grains at high temperature are underabundant but elements of low condensation temperature are much less underabundant. This pattern is ascribed to a separation of dust fro

Jonathan E. Baker, Marc Davis

We describe a new statistic for measuring the small-scale velocity dispersion of galaxies directly from redshift surveys. This statistic is based on the object-weighted statistic proposed by Davis, Miller, & White (1997). Compared with the traditional pair-weighted velocity dispersion, our statistic is less sensitive to the presence or absence of rare, rich

F. Krennrich, S. Le Bohec, T. C. Weekes

Gamma-ray observations above 200 MeV are conventionally made by satellite-based detectors. The EGRET detector on the Compton Gamma Ray Observatory (CGRO) has provided good sensitivity for the detection of bursts lasting for more than 200 ms. Theoretical predictions of high-energy gamma-ray bursts produced by quantum-mechanical decay of primordial black holes

A. Rosen, P. E. Hardee

We investigate the growth of jet plus entrained mass in simulations of supermagnetosonic cylindrical and expanding jets. The entrained mass spatially grows in three stages: from an initially slow spatial rate to a faster rate and finally at a flatter rate. These stages roughly coincide with the similar rates of expansion in simulated radio intensity maps, an

Wendy L. Freedman

The Hubble constant, which measures the expansion rate, together with the total energy density of the Universe, sets the size of the observable Universe, its age, and its radius of curvature. Excellent progress has been made recently toward the measurement of the Hubble constant: a number of different methods for measuring distances have been developed and r

Philip E. Hardee

The properties of wave-like helically twisted normal mode structures on steady relativistic jets are summarized. Wave speeds are a function of the wavelength and less than the jet speed. However, normal mode interference can lead to both stationary and superluminal phase effects. A maximum pressure fluctuation criterion suggested by numerical simulations of

E. Ellingson, H. Lin, H. K. C. Yee, R. G. Carlberg

We present a principal component analysis of galaxy spectra from the CNOC sample of rich X-ray luminous clusters at 0.18 < z < 0.55. Composite radial distributions of different stellar populations show strong gradients as a function of cluster-centric redshift. The composite population is dominated by evolved populations in the core, and gradually changes to

M. G. Witte, G. J. Savonije

We study the tidal evolution of a binary system consisting of a 1.4 Msun compact object in elliptic orbit about a 10 Msun uniformly rotating main sequence star for various values of the initial orbital parameters. We apply our previously published results of 2D non-adiabatic calculations of the non-radial g- and r-mode oscillations of the uniformly rotating

Thomas H. Reiprich, Hans Boehringer

One hundred and six galaxy clusters have been studied in detail using X-ray data and important global physical properties have been determined. Correlations between these properties are studied with respect to the description of clusters as a self-similar class of objects. The results support the self-similar picture only partly and significant deviations ar

T. Richard Carson

Generalizing a result for the binary lens, similar alternative expressions are also given for the Jacobian determinant for a gravitational lens consisting of an arbitrary number of discrete lensing centres, with arbitrary masses and locations in a plane. The results for a binary lens are recovered, agreeing with some already known results, and correcting err

D. de Martino, R. Silvotti, D. A. H Buckley, B. T. Gänsicke

Time resolved spectroscopy of the Intermediate Polar FO Aqr reveals the presence of multiple periodicities in the UV range. A strong orbital modulation dominates both continuum and emission line flux variabilities, while line velocity motions are only detected at the rotational frequency. A prominent orbital periodicity is also observed in coordinated optica

P. M. W. Kalberla, Yu. A. Shchekinov, R. -J. Dettmar

We present a model for the interpretation of the gamma-ray background emission from the Galactic halo, which we attribute to interaction of high-energy cosmic rays with dense molecular clumps. In a wide range of clump parameters we calculate the expected gamma-photon flux, taking into account for the first time optical depth effects. This allows us to derive

Ohad Shemmer, Elia M. Leibowitz, Paula Szkody

We report optical photometric and spectroscopic observations of the M33 star B416, establishing it as the fifth identified LBV in that galaxy. The B magnitude of the star varies with a period of 8.26 day and an amplitude of 0.03 magnitude. The red end of the optical spectrum does not seem to partake in these oscillations, which we identify as the microvariat

Ian R. Stevens, David M. Acreman, Trevor J. Ponman

The dynamical signatures of the interaction between galaxies in clusters and the intracluster medium (ICM) can potentially yield significant information about the structure and dynamical history of clusters. To develop our understanding of this phenomenon we present results from numerical modelling of the galaxy/ICM interaction, as the galaxy moves through t

Antonella Vallenari, Andrea Richichi, Giovanni Carraro, Leo Girardi

We present photometry in the J and K near-infrared bands for two regions centered on the young open clusters NGC 1893 and Berkeley 86. We study 700 stars down to K = 17 in the field of NGC 1893, and about 2000 stars in the field of Berkeley 86 down to K$\sim$ 16.5, for which near-infrared photometry was insofar not available. Coupling J-K data with UBV photo

M. O. Hanski, P. Teerikorpi, T. Ekholm, G. Theureau

The KLUN (Kinematics of the Local UNiverse) sample of 6600 spiral galaxies is used in studying dark matter in different scales: Type dependence of the zero-point of Tully-Fisher relation indicates M/L \approx 9 -- 16 in galactic scale. Preliminary results from a study of selection effect influencing double galaxies give a larger value M/L \approx 30 -- 50. S

Fumiaki Nakata, Kazuhiro Shimasaku, Mamoru Doi, Nobunari Kashikawa

We investigate pure luminosity evolution models for early-type (elliptical and S0) galaxies (i.e., no number density change or morphology transition), and examine whether these models are consistent with observed number counts in the B, I and K bands and redshift distributions of two samples of faint galaxies selected in the I and K bands. The models are cha

Matthew Colless, R. P. Saglia, David Burstein, Roger Davies

The EFAR project has measured peculiar motions in two distant volumes of the universe using Fundamental Plane (FP) distances for 85 clusters with cz=6000-15000 km/s. The scatter in distance about the FP is observed to be 20% per galaxy for EFAR sample, resulting in peculiar velocities with a median precision of 1075 km/s for the 50 clusters with 3 or more ga

G. Hebrard, C. Mallouris, R. Ferlet, D. Koester

We present new observations of the binary Sirius A / Sirius B performed with HST-GHRS. Two interstellar clouds are detected on this sightline, one of them being identified as the Local Interstellar Cloud (LIC). The interstellar structure of this sightline is constrained by high spectral resolution data of the species OI, NI, SiII, CII, FeII and MgII. Lyman a

Bartolo Luque, Antonio Ferrera

During the last few years an area of active research in the field of complex systems is that of their information storing and processing abilities. Common opinion has it that the most interesting beaviour of these systems is found ``at the edge of chaos&#39;&#39;, which would seem to suggest that complex systems may have inherently non-trivial information pr

CDF Collaboration

This paper reports an updated measurement of the Standard Model CP violation parameter $\sin2β$ using the CDF Detector at Fermilab. The entire Run I data sample of 110 pb$^{-1}$ of proton antiproton collisions at $\sqrt{s}=1.8 TeV$ is used to identify a signal sample of $\sim 400$ $B \to J/ψK^0_S$ events, where $J/ψ\to μ^+μ^-$ and $K_S^0 \to π^+π^-$. The fla

Leonard Susskind, Nicolaos Toumbas

There is substantial evidence that string theory on AdS_5 x S_5 is a holographic theory in which the number of degrees of freedom scales as the area of the boundary in Planck units. Precisely how the theory can describe bulk physics using only surface degrees of freedom is not well understood. A particularly paradoxical situation involves an event deep in th

Thomas G. Rizzo

With one extra dimension, current high precision electroweak data constrain the masses of the first Kaluza-Klein excitations of the Standard Model gauge fields to lie above $\simeq 4$ TeV. States with masses not much larger than this should be observable at the LHC. However, even for first excitation masses close to this lower bound, the second set of excita

S. C. Benjamin

Typical quantum computing schemes require transformations (gates) to be targeted at specific elements (qubits). In many physical systems, direct targeting is difficult to achieve; an alternative is to encode local gates into globally applied transformations. Here we demonstrate the minimum physical requirements for such an approach: a one-dimensional array c

H. Hoppe, U. Zuelicke, Gerd Schoen

We have studied the interplay of Andreev reflection and cyclotron motion of quasiparticles at a superconductor-normal-metal interface with a strong magnetic field applied parallel to the interface. Bound states are formed due to the confinement introduced both by the external magnetic field and the superconducting gap. These bound states are a coherent super

F. del Aguila, J. A. Aguilar-Saavedra

Zt and gamma t production with Z -> l+ l- and t -> Wb -> l nu b provides the best determination of top flavour-changing neutral couplings at the LHC. The bounds on tc couplings eventually derived from these processes are similar to those expected from top decays, while the limits on tu couplings are better by a factor of two. The other significant Z and W de

J. Krug, J. Garcia

We study interacting particle systems on the real line which generalize the Hammersley process [D. Aldous and P. Diaconis, Prob. Theory Relat. Fields 103, 199-213 (1995)]. Particles jump to the right to a randomly chosen point between their previous position and that of the forward neighbor, at a rate which may depend on the distance to the neighbor. A class

H. Panagopoulos, E. Vicari

We show how to perform a resummation, to all orders in perturbation theory, of a certain class of gauge invariant tadpole-like diagrams in Lattice QCD. These diagrams are often largely responsible for lattice artifacts. Our resummation leads to an improved perturbative expansion. Applied to a number of cases of interest, e.g. the lattice renormalization of s

Nicholas J. Ramer, Andrew M. Rappe

We present a new method for modeling disordered solid solutions, based on the virtual crystal approximation (VCA). The VCA is a tractable way of studying configurationally disordered systems; traditionally, the potentials which represent atoms of two or more elements are averaged into a composite atomic potential. We have overcome significant shortcomings of

Juergen Engels, Tereza Mendes

We investigate the three-dimensional O(4)-model on 24^3--96^3 lattices as a function of the magnetic field H. Below the critical point, in the broken phase, we confirm explicitly the H^{1/2} dependence of the magnetization and the corresponding H^{-1/2} divergence of the longitudinal susceptibility, which are predicted from the existence of Goldstone modes.

Marco Fabbrichesi

I review the current theoretical estimates of the CP-violating parameter eps&#39;/eps, compare them to the experimental result and suggest a few guidelines in using the theoretical results.

M. M. Kettenis, L. G. Suttorp

Path-integral methods can be used to derive a `path-decomposition expansion&#39; for the temperature Green function of a magnetized free-electron gas confined by a hard wall. With the help of this expansion the asymptotic behaviour of the profiles for the excess particle density and the electric current density far from the edge is determined for arbitrary v

A. Tartaglia

The essence of the gravitomagnetic clock effect is properly defined showing that its origin is in the topology of world lines with closed space projections. It is shown that, in weak field approximation and for a spherically symmetric central body, the loss of synchrony between two clocks counter-rotating along a circular geodesic is proportional to the angu

L. Henderson, V. Vedral

Previously proposed measures of entanglement, such as entanglement of formation and assistance, are shown to be special cases of the relative entropy of entanglement. The difference between these measures for an ensemble of mixed states is shown to depend on the availability of classical information about particular members of the ensemble. Based on this, re

Aharon Casher, Benni Reznik

Measurements are ordinarily described with respect to absolute &#34;Newtonian&#34; time. In reality however, the switching-on of the measuring device at the instance of the measurement requires a timing device. Hence the classical time $t$ must be replaced by a suitable quantum time variable $τ$ of a physical clock. The main issue raised in this article is t

W. A. Hofer

Single-slit and two-slit interferometer measurements of electrons are analyzed within the realistic model of particle propagation. In a step by step procedure we show that all current models of interference are essentially non-local and demonstrate that the treatment of the quantum theory of motion is the simplest model for the scalar problem. In particular

S. J. Childs, B. D. Reddy

A logical explanation as to why the choice of the Pian-Sumihara basis (as a linear basis to approximate stress) leads to greater efficiency in enhanced strain problems, is presented. An Airy stress function and the consequent selective simplification resulting from the differentiation of an implied, single, parent approximating polynomial, are the essence of

Subrata Pal, Song Gao, Horst Stöcker, Walter Greiner

We investigate in stable strange hadronic matter (SHM) the modification of the masses of the scalar ($σ$, $σ^*$) and the vector ($ω$, $ϕ$) mesons. The baryon ground state is treated in the relativistic Hartree approximation in the nonlinear $σ$-$ω$ and linear $σ^*$-$ϕ$ model. In stable SHM, the masses of all the mesons reveal considerable reduction due to la

H. M. Ding, J. Huefner

The probability of a projectile nucleon to traverse a target nucleus without interaction is calculated for central Si-Cu and Si-Pb collisions. Special attention is given to the impact parameter range which contributes to events with large transverse energy. A fit to the data from E814 requires an effective NN cross section of sigma_eff=54.2+-5.0mb (compared

E864 Collaboration, T. A. Armstrong

We present measurements from Brookhaven Experiment 864 of neutron invariant multiplicity in 11.5 A GeV/c Au+Pb collisions. The measurements span a rapidity range from center-of-mass to beam rapidity (y(beam)=3.2) and are presented as a function of event centrality. The results are compared with E864 measurements of proton invariant multiplicity and an averag

T. Mansour

In this paper we calculate the cardinality of the set S_n(T,tau) of all permutations in S_n that avoid one pattern from S_4 and a nonempty set of patterns from S_3.

Alan Adolphson, Steven Sperber

We give two applications of our earlier work &#34;Exponential sums on A^n, II&#34; (math.AG/9909009). We compute the p-adic cohomology of certain exponential sums on A^n involving a polynomial whose homogeneous component of highest degree defines a projective hypersurface with at worst weighted homogeneous isolated singularities. This study was motivated by

Torsten Ehrhardt, Ilya M. Spitkovsky

Let G be a piecewise constant $n\times n$ matrix function which is defined on a smooth closed curve $Γ$ in the complex sphere and which has m jumps. We consider the problem of determining the partial indices of the factorization of the matrix function G in the space $L^p(Γ)$. We show that this problem can be reduced to a certain problem for systems of linear

Qiudong Wang, Lai-Sang Young

This work contains the results from a comprehensive study of a new class of attractors. The attractors in this class are characterized by strong local instability, but they are not uniformly hyperbolic. Rigorous results on their dynamical, geometric and statistical properties are presented.

Timo Seppalainen

We study the evolution of a small perturbation of the equilibrium of a totally asymmetric one-dimensional interacting system. The model we take as example is Hammersley&#39;s process as seen from a tagged particle, which can be viewed as a process of interacting positive-valued stick heights on the sites of Z. It is known that under Euler scaling (space and

Victor Alexandrov

In the previous version of the paper it was announced that ``sphere homeomorphic flexible polyhedra (with self intersections) do really exist in n-dimensional Euclidean, Lobachevskij and spherical spaces for each $n\geq 3$.&#39;&#39; Now the paper has been withdrawn by the author, due a crucial error in the proof of the main theorem.

Cecile Drouet

Let $E_{n}$ be an holomorphic bundle of rank two on an algebraic curve $X$ (the degree of $E_{n}$ is $n$ apart from an additive constant). Note by $Met(E_{n})$ the space of hermitian metrics $h$ on $E_{n}$. Also, consider $Met(W_{n})$, the space of metrics on $H^{0}(X,E_{n})$. Although $Met(W_{n})$ is finite dimensional, it&#39;s dimension grows with $n$. So

Roger Ellman

The recently developed proof of Fermat&#39;s Last Theorem is very lengthy and difficult, so much so as to be beyond all but a small body of specialists. While certainly of value in the developments that resulted, that proof could not be, nor was offered as being, possibly the proof Fermat had in mind. The present proof being brief, direct and concise is a ca

Arthur Bartels, Peter Teichner

We show that any number of disjointly embedded 2-spheres in 4-space can be pulled apart by a link homotopy, ie, by a motion in which the 2-spheres stay disjoint but are allowed to self-intersect.

Ioannis Giannakis, James T. Liu, Massimo Porrati

We derive model independent, non-perturbative supersymmetric sum rules for the gravitational quadrupole moments of arbitrary-spin particles in any N=1 supersymmetric theory. These sum rules select a ``preferred&#39;&#39; value of h=1 where the ``h-factor&#39;&#39; is the gravitational quadrupole analog of the gyromagnetic ratio or g-factor. This value of h=1

K. Foerger

We study open descendants of four dimensional Z_N x Z_M orbifolds of the non-supersymmetric type 0B string theory. An exhaustive analysis shows, that using the crosscap constraint the only model for which one can project out the tachyon is the Z_2 x Z_2 orbifold. For this case we explicitly construct the open string amplitudes. The gauge group corresponding

M. Pawlowski, V. N. Pervushin, V. I. Smirichinski

The quantization of General Relativity invariant with respect to time-reparametrizations is considered. We construct the Faddeev-Popov generating functional for the unitary perturbation theory in terms of invariants of the kinemetric group of diffeomorphisms of a frame of reference as a set of Einstein&#39;s observers with the equivalent Hamiltonian descript

Yishi Duan, Libin Fu, Xin Liu

Topological property in a spinning system should be directly associated with its wavefunction. A complete decomposition formula of SU(2) gauge potential in terms of spinning wavefunction is established rigorously. Based on the $ϕ$-mapping theory and this formula, one proves that the second Chern class is inherent in the spinning system. It is showed that thi

R. D. Peccei

In this overview, I discuss some of the open issues in Kaon physics. After briefly touching on lattice calculations of Kaon dynamics and tests of CPT, my main focus of attention is on epsilon prime over epsilon and on constraints on the CKM model. The impact of rare K- decays and of experiments with B-mesons for addressing the issue of CP-violation is also d

J. Ellis, M. Karliner, D. E. Kharzeev, M. G. Sapozhnikov

We have previously interpreted the various large apparent violations of the naive Okubo-Zweig-Iizuka (OZI) rule found in many channels in $\bar{p}p$ annihilation at LEAR as evidence for an intrinsic polarized $\bar{s}s$ component of the nucleon wave function. The model is further supported by new data from LEAR and elsewhere. Here we discuss in more detail t

Stanley J. Brodsky

I discuss several theoretical tools which are useful for analyzing perturbative and non-perturbative problems in quantum chromodynamics, including (a) the light-cone Fock expansion, (b) the effective charge $α_V$, (c) conformal symmetry, and (d) commensurate scale relations. Light-cone Fock-state wavefunctions encode the properties of a hadron in terms of it

R. D. Peccei

These lectures describe why one believes there is physics beyond the Standard Model and review the expectations of three alternative explanations for the Fermi scale. After examining constraints and hints for beyond the Standard Model physics coming from experiment, I discuss, in turn, dynamical symmetry breaking, supersymmetry and extra compact dimension sc

J. F. Beacom

The next core-collapse supernova in our Galaxy will be a spectacular event, with some $10^4$ neutrino detections in total expected among several detectors. This data will allow unprecedented tests of neutrino properties and new opportunities in astrophysics. In this paper, I focus on two main topics: (1) Measurement of the $ν_μ$ and $ν_τ$ masses by time-of-f

A. Gehrmann-De Ridder, H. Spiesberger, P. M. Zerwas

The electromagnetic and weak structure functions of the photon can be studied in the deep inelastic electron-photon processes e+gamma -> e+X and e+gamma -> nu+X. While at low energies only virtual photon exchange is operative in the neutral-current process, additional Z-exchange becomes relevant for high Q2 of order MZ^2 at e+e- linear colliders. Likewise th

R. Rapp, J. Wambach

The current theoretical status in the analysis and interpretation of low-mass dilepton measurements in (ultra-) relativistic heavy-ion experiments is reviewed. Special emphasis is put on potential signals of (partial) restoration of dynamically broken chiral symmetry in a hot and dense hadronic medium. It follows from chiral symmetry alone that parity partne

A. Bottino, F. Donato, N. Fornengo, S. Scopel

We discuss the effect induced on the neutralino-nucleon cross-section by the present uncertainties in the values of the quark masses and of the quark scalar densities in the nucleon. We examine the implications of this aspect on the determination of the neutralino cosmological properties, as derived from measurements of WIMP direct detection. We show that, w

Katri Huitu, Yoshiharu Kawamura, Tatsuo Kobayashi, Kai Puolamaki

We study non-universal corrections to the gauge couplings due to higher dimensional operators in supersymmetric SU(5) grand unified theories. The corrections are, in general, parametrized by three components originating from {\bf 24}, {\bf 75} and {\bf 200} representations. We consider the prediction of $α_3(M_Z)$ along each {\bf 24}, {\bf 75} and {\bf 200}

Einan Gardi, Georges Grunberg

Infrared power corrections for the average thrust < T > in e+e- annihilation are analyzed in the framework of renormalon resummation, motivated by analogy with the skeleton expansion in QED and the BLM approach. Performing the ``massive gluon&#39;&#39; renormalon integral a renormalization scheme invariant result is obtained. We find that a major part of the

J. G. Koerner, F. Krajewski, A. A. Pivovarov

We analyze tau lepton decay observables, namely moments of the hadronic spectral density in the finite energy interval (0,M_τ), within finite order perturbation theory including α_s^4 corrections. The start of asymptotic growth of perturbation theory series is found at this order in a scheme invariant manner. We establish the ultimate accuracy of finite orde

K. R. Long

The luminosity of the electron-proton collider, HERA, will be increased by a factor of five during the long shutdown in the year 2000. At the same time longitudinal lepton beam polarisation will be provided for the collider experiments H1 and ZEUS. These far reaching upgrades to the machine will be matched by upgrades to the detectors. The result will be a u

Feng Yuan, Hui-Shi Dong, Li-Kun Hao, Kuang-Ta Chao

Presented here is a calculation of inelastic $J/ψ$ production in polarized photon-hadron collisions under the framework of NRQCD factorization formalism. We consider the photoproduction of $\jpsi$ in the energy range relevant to HERA. The Weizsäcker-Williams approximation is adopted in the evaluation of the cross sections for $ep$ collisions. We found that t

E. Kuraev, A. Schiller, V. Serbo, B. Shaikhatdenov

We study the small--angle double bremsstrahlung in $e^-e^\pm$ scattering for a jet kinematics where both photons move along the electron direction. This region gives the main contribution to the cross section. We present analytic expressions for all 64 amplitudes with arbitrary helicity states of the initial and final leptons and the produced photons conveni

Kazuo Koike

On the basis of see-saw mechanism, possible generation structure is investigated. Assuming that right-handed neutrinos are realistic particles below GUTs mass, it is shown that there is a choice of new scheme of generation,where the combination of leptons and quarks is different from the ordinary one. Our scheme predict a new proton decay mode.

Hai-Yang Cheng

The $K\toππ$ decay amplitudes are studied within the framework of generalized factorization in which the effective Wilson coefficients are gauge-invariant, renormalization-scale and -scheme independent while factorization is applied to the tree-level hadronic matrix elements. Nonfactorized contributions to the hadronic matrix elements of (V-A)(V-A) four-quar

A. Gonzalez-Arroyo, C. Pena

The Nahm transformation is a duality mapping between self-dual Yang-Mills configurations on the torus, which exchanges the number of colours with the topological charge. We show how lattice gauge theory techniques can be used to implement it numerically. The method is presented and its precision illustrated with some applications.

C. Peterson

Recent advances in coarse-grained lattice and off-lattice protein models are reviewed. The sequence dependence of thermodynamical folding properties are investigated and evidence for non-randomness of the binary sequences of good folders are discussed. Similar patterns for non-randomness are found for real proteins. Dynamical parameter MC methods, such as th

Ting-Wai Chiu

The condition for a lattice Dirac operator D to reproduce correct chiral anomaly at each site of a finite lattice for smooth background gauge fields is that D possesses exact zero modes satisfying the Atiyah-Singer index theorem. This is also the necessary condition for D to have correct fermion determinant (ratio) which plays the important role of incorpora

Attilio Cucchieri, Frithjof Karsch

We evaluate the electric and magnetic screening masses from the long-distance behavior of the (temporal and spatial) gluon correlation functions, for pure SU(2) gauge theory at finite temperature. In order to investigate the gauge dependence of the screening masses we consider seven different gauges. We also evaluate these masses using different definitions

K. Farakos, G. Koutsoumbas, N. Mavromatos, A. Momen

The magnetically induced fermionic condensate is studied at zero and finite temperatures. The effects of a non-homogeneous external magnetic fields is briefly considered.

P. H. Damgaard, R. G. Edwards, U. M. Heller, R. Narayanan

In the large-volume limit $V\to\infty$ with $V << 1/m_π^4$ the mass-dependent chiral condensate is predicted to satisfy exact finite-volume scaling laws that fall into three major universality classes. We test these analytical predictions with staggered fermions and overlap fermions in gauge field sectors of fixed topological charge $ν$.

H. Nakajima, S. Furui

We present the first results of numerical test of the Kugo-Ojima confinement criterion in the lattice Landau gauge. The Kugo-Ojima criterion of colour confinement in the BRS formulation of the continuum gauge theory is given by $u_b^a(p^2)=-δ_b^a$, where $u_b^a$ is defined by the two point function of the Faddeev-Popov ghost fields $c, \bar c$ and the gauge

Mark Oreglia

Recent LEP searches for Higgs bosons in models other than the Minimal Standard Model and the Minimal Supersymetric Standard Model are reviewed. Limits are presented for Higgs bosons decaying into diphotons or invisible particles, and for charged Higgs bosons.

H. Genreith

In 1919 A. Einstein suspected first that gravitational fields could play an essential role in the structure of elementary particles. In 1937, P.A.M. Dirac found a miraculous link between the properties of the visible Universe and elementary particles. Both conjectures stayed alive through the following decades but still no final theory could be derived to th

Sougato Bose, Anupam Mazumdar

We present a fully quantum version of the holographic principle in terms of quantum systems, subsystems, and their interactions. We use the concept of environment induced decoherence to prove this principle. We discuss the conditions under which the standard (semi-classical) holographic principle is obtained from this quantum mechanical version.

F. Finelli, A. Gruppuso, G. Venturi

We extend our analysis for scalar fields in a Robertson-Walker metric to the electromagnetic field and Dirac fields by the method of invariants. The issue of the relation between conformal properties and particle production is re-examined and it is verified that the electromagnetic and massless spinor actions are conformal invariant, while the massless confo

Afzal Ballim, Vincenzo Pallotta

This paper describes how robust parsing techniques can be fruitful applied for building a query generation module which is part of a pipelined NLP architecture aimed at process natural language queries in a restricted domain. We want to show that semantic robustness represents a key issue in those NLP systems where it is more likely to have partial and ill-f

Jaime Merino, Ross H. McKenzie

The temperature dependence of the transport properties of the metallic phase of a frustrated Hubbard model on the hypercubic lattice at half-filling are calculated. Dynamical mean-field theory, which maps the Hubbard model onto a single impurity Anderson model that is solved self-consistently, and becomes exact in the limit of large dimensionality, is used.

E. Somfai, L. M. Sander, R. C. Ball

We discuss the scaling of characteristic lengths in diffusion limited aggregation (DLA) clusters in light of recent developments using conformal maps. We are led to the conjecture that the apparently anomalous scaling of lengths is due to one slow crossover. This is supported by an analytical argument for the scaling of the penetration depth of newly arrived

Alexander N. Korotkov

We consider the continuous measurement of a double quantum dot by a weakly coupled detector (tunnel point contact nearby). While the conventional approach describes the gradual system decoherence due to the measurement, we study the situation when the detector output is explicitly recorded that leads to the opposite effect: gradual purification of the double

E. V. L. de Mello

We use the two dimensional extended Hubbard Hamiltonian with the position of the attractive potential as a variable parameter with a BCS type approach to study the interplay between the superconductor transition temperature $T_c$ and hole content for high temperature superconductors. This novel method gives some insight on the range and intensity of the Coop

E. V. L. de Mello

A number of recent experiments have suggested the presence of either real or complex components in the gap symmetry of high-$T_c$ superconductors (HTSC). In this paper we introduce a novel approach to study the competition of such complex order parameter mixtures by varying the position of the two-body attractive potential in a two dimensional extended Hubba

M. E. Foglio, M. S. Figueira

The exact Green&#39;s functions of the periodic Anderson model for $U\to \infty $ are formally expressed within the cumulant expansion in terms of an effective cumulant. Here we resort to a calculation in which this quantity is approximated by the value it takes for the exactly soluble atomic limit of the same model. In the Kondo region a spectral density is

Dirk Helbing, Martin Treiber

Macroscopic traffic simulations are based on coupled non-linear partial differential equations, the solutions of which are either shock-like or inhomogeneous with steep gradients, at least in the interesting density regime. We discuss several suitable explicit integration schemes, including their advantages and disadvantages, their numerical robustness and e

P. H. Rivera, N. Studart, P. A. Schulz

The evolution of two coupled mini-bands, generated by alternating barrier widths dimerization of a superlattice, driven by intense AC fields is investigated. The present model delivers a useful framework for the transition between the analytical high frequency regime and the extreme low frequency limit described by models based on Fukuyama&#39;s {\it et al.}

Vishal Mehra, Jayme De Luca

We simulate a finite system of $N$ confined electrons with inclusion of the Darwin magnetic interaction in two- and three-dimensions. The lowest energy states are located using the steepest descent quenching adapted for velocity dependent potentials. Below a critical density the ground state is a static Wigner lattice. For supercritical density the ground st

Matthieu Micoulaut

Simple statistical agglomeration models can provide a universal link between the local structure and the glass transition temperature in network glasses. We first stress the physical features of the models and the hypothesis made, and then show how to define the glass transition temperature. The models are applied to various types of binary, ternary and mult

C. Bergemann, S. R. Julian, A. P. Mackenzie, S. NishiZaki

We apply a novel analysis of the field and angle dependence of the quantum-oscillatory amplitudes in the unconventional superconductor Sr2RuO4 to map its Fermi surface in unprecedented detail, and to obtain previously inaccessible information on the band dispersion. The three quasi-2D Fermi surface sheets not only exhibit very diverse magnitudes of warping,

Rudolf Haussmann

The influence of a uniform rotation with frequency Omega on the critical behavior of liquid 4He near T_lambda is investigated. We apply our recently developed approach which is a renormalization-group theory based on model F starting with the calculation of the Green&#39;s function in Hartree approximation. We calculate the specific heat, the correlation len

Hisashi Kondo, Tôru Moriya

A phase diagram is drawn in a parameter space of the nearly half-filled single band two-dimensional Hubbard model with U/t, t&#39;/t and n as the parameters, U, t, t&#39; and n being the on-site interaction, the nearest and second nearest neighbor transfer matrices and the number of electrons per site, respectively. The parameter space is chosen so as to inc

Ryo Maezono, Naoto Nagaosa

In a form which include the mother compound, we studied the extended Hubbard-type model with the orbital degeneracy for any doping concentration. Meanfield phase diagram and the spin wave excitation in RPA are calculated. It turned out that a large orbital polarization is essential to reproduce the magnetic phases depending on the doping concentration. Base

P. H. Rivera, P. A. Schulz

We follow the evolution of dressed coupled mini-bands as a function of an AC field intensity, non perturbatively, for a wide field frequency range. High and low frequency limits are characterized by two different dynamic localization regimes, clearly separated by a breakdown region in a quasi-energy map. Signatures of a insulator-metal like transition by mea

J. Lopez, V. Dediu, P. Nozar, G. Ruani

We report a study of polycrystalline samples of the family La1-xCdxMnO3+dwith different percentage of Mn4+ ions. X-rays diffraction, Iodometric titration, Raman, Magnetic and Electrical Resistivity measurements provide a general characterisation of the physical properties. Results are qualitatively similar to the ones found in Ca doped manganese perovskites.