March 1996 arXiv papers — page 4

D. Apostolakis, P. Ditsas, S. Katsanevas

We present and study the results for the standard model process $e^+e^-\to ν\barνb\bar{b}$ at c.m energies 150$\leq \sqrt{s} (GeV) \leq $ 240 and for Higgs boson masses $80 GeV \leq m_H \leq 120 GeV$, obtained from all tree-level diagrams and including the most important radiative corrections. The $\sqrt{s}$ dependence and the interference properties of the

Gerard Watts

Langlands et al. considered two crossing probabilities, pi_h and pi_{hv}, in their extensive numerical investigations of critical percolation in two dimensions. Cardy was able to find the exact form of pi_h by treating it as a correlation function of boundary operators in the Q goes to 1 limit of the Q state Potts model. We extend his results to find an anal

Guy D. Moore

I investigate the evolution of finite temperature, classical Yang-Mills field equations under the influence of a chemical potential for Chern Simons number $N_{CS}$. The rate of $N_{CS}$ diffusion, $Γ_d$, and the linear response of $N_{CS}$ to a chemical potential, $Γ_μ$, are both computed; the relation $Γ_d = 2 Γ_μ$ is satisfied numerically and the results

I. Jack, D. R. T. Jones, C. G. North

We calculate the three loop anomalous dimension for a general $N=1$ supersymmetric gauge theory. The result is used to probe the possible existence of renormalisation invariant relationships between the Yukawa and gauge couplings.

A. Perez, M. Rausch de Traubenberg, P. Simon

A 2D- fractional supersymmetry theory is algebraically constructed. The Lagrangian is derived using an adapted superspace including, in addition to a scalar field, two fields with spins 1/3,2/3. This theory turns out to be a rational conformal field theory. The symmetry of this model goes beyond the super Virasoro algebra and connects these third-integer spi

Jörg Teschner

By introducing a nonlinearly transforming goldstino field non-super\-sym\-metric matter can be coupled to supergravity. This implies the possibility of coupling a standard model with one Higgs to supergravity.

Mirjam Cvetic, Donam Youm

We give the explicit expression for four-dimensional rotating charged black hole solutions of N=4 (or N=8) superstring vacua, parameterized by the ADM mass, four charges (two electric and two magnetic charges, each arising from a different U(1) gauge factors), and the angular momentum (as well as the asymptotic values of four toroidal moduli of two-torus and

S. Yu. Khlebnikov, I. I. Tkachev

We present the first fully non-linear calculation of inflaton decay. We map inflaton decay onto an equivalent classical problem and solve the latter numerically. In the $λϕ^4$ model, we find that parametric resonance develops slower and ends at smaller values of fluctuating fields, as compared to estimates existing in literature. We also observe a number of

Yoshio Koide

On the basis of a seesaw-type mass matrix model for quarks and leptons, $M_f \simeq m_L M_F^{-1} m_R$, where $m_L\propto m_R$ are universal for $f=u,d,ν$ and $e$ (up-quark-, down-quark-, neutrino- and charged lepton-sectors), and $M_F$ has a form [(unit matrix)+(democratic-type matrix)], neutrino masses and mixings are investigated. It is tried to understand

Eric Gawiser, George F. Smoot

We estimate the level of confusion to Cosmic Microwave Background anisotropy measurements caused by extragalactic infrared sources. CMB anisotropy observations at high resolution and high frequencies are especially sensitive to this foreground. We use data from the COBE satellite to generate a Galactic emission spectrum covering mm and sub-mm wavelengths. Us

S. Majid

We develop a gauge theory or theory of bundles and connections on them at the level of braids and tangles. Extending recent algebraic work, we provide now a fully diagrammatic treatment of principal bundles, a theory of global gauge transformations, associated braided fiber bundles and covariant derivatives on them. We describe the local structure for a conc

Thomas Kerler

We consider a generalization of the axioms of a TQFT, so called half-projective TQFT's, with an anomaly, $x^μ$, in the composition law. $μ$ is a coboundary on the cobordism categories with non-negative, integer values. The element $x$ of the ring over which the TQFT is defined does not have to be invertible. In particular, it may be 0. This modification

Horst Mueller, Brian D. Serot

The properties of high-density nuclear and neutron matter are studied using a relativistic mean-field approximation to the nuclear matter energy functional. Based on ideas of effective field theory, nonlinear interactions between the fields are introduced to parametrize the density dependence of the energy functional. Various types of nonlinearities involvin

G. G. Ryzhikh

Assuming that NN interaction is modified inside a nucleus by a specific way, phenomenological effective broad core (BC) NN potential is constructed. It is shown that increase in the width of repulsive core lets us describe the Coulomb form factors of few-body nuclei on the basis of nucleonic degrees of freedom only.

Nico M. Temme

We consider the asymptotic behavior of the incomplete gamma functions gamma(-a,-z) and Gamma(-a,-z) as a goes to infinity. Uniform expansions are needed to describe the transition area z~a in which case error functions are used as main approximants. We use integral representations of the incomplete gamma functions and derive a uniform equation by applying te

G W Gibbons

I exhibit a middle-dimensional square integrable harmonic form on the moduli space of distinct fundamental BPS monopoles of an arbitrary Lie group. This is in accord with Sen's S-duality conjecture. I also show that the moduli space has no closed or bound geodesics.

Alfredo Macias, Tonatiuh Matos

In this paper, we present a new solution for the effective theory of Maxwell--Einstein--Dilaton, Low energy string and Kaluza--Klein theories, which contains among other solutions the well known Kaluza--Klein monopole solution of Gross--Perry--Sorkin as special case. We show also the magnetic and electric dipole solutions contained in the general one.

S. P. Gavrilov, D. M. Gitman

We study particles creation in arbitrary space-time dimensions by external electric fields, in particular, by fields, which are acting for a finite time. The time and dimensional analysis of the vacuum instability is presented. It is shown that the distributions of particles created by quasiconstant electric fields can be written in a form which has a therma

Edward Witten

Phase transitions are studied in $M$-theory and $F$-theory. In $M$-theory compactification to five dimensions on a Calabi-Yau, there are topology-changing transitions similar to those seen in conformal field theory, but the non-geometrical phases known in conformal field theory are absent. At boundaries of moduli space where such phases might have been expec

Akio Sugamoto

On the occasion of the 60th birthday of Professor Keiji Kikkawa, Kikkawa-type physics performed at Ochanomizu was personally reviewed, and the generation of the metric is discussed with the condensation of the string fields.

J. Gomis, K. Kamimura, R. Kuriki

The Wess-Zumino term of the spinning string is constructed in terms of their anomalies using an extended field-antifield formalism. A new feature appears from a fact that the non-anomalous transformations do not form a sub-group. The algebra of the extended variables closes only using the equations of motion derived from the WZ term.

Ephraim Fischbach

We explore the limits on neutrino mass which follow from a study of the long-range forces that arise from the exchange of massless or ultra-light neutrinos. Although the 2-body neutrino-exchange force is unobservably small, the many-body force can generate a very large energy density in neutron stars and white dwarfs. We discuss the novel features of neutrin

A. T. Davies, C. D. Froggatt, R. G. Moorhouse

In the electroweak phase transition there arises the problem of baryon number washout by sphaleron transitions, which can be avoided if the phase transition is strongly enough first order. The minimal supersymmetric standard model has just two Higgs doublets H1 and H2, while the next to minimal model, NMSSM, has an additional singlet, N, this latter giving r

Michael C. Birse, Boris Krippa

The quark condensate in nuclear matter contains a term of order $ρm_π$, arising from the contribution of low-momentum virtual pions to the $πN$ sigma commutator. Standard treatments of QCD sum rules for a nucleon in matter generate a similar term in the nucleon effective mass, although this is inconsistent with chiral perturbation theory. We show how an impr

G. Kramer, H. Spiesberger

We present a new calculation of the $O(α_s^2)$ coefficient of the energy-energy correlation function (EEC) using two different schemes to cancel infrared and collinear poles. The numerical evaluation uses the phase space slicing and the hybrid subtraction method. Both schemes converge with decreasing slicing cut. The results are independent of the scheme for

A. Nicolaidis, A. Taramopoulos

The rise with energy of the neutrino--nucleon cross section implies that at energies above few TeV the Earth is becoming opaque to cosmic neutrinos. The neutrinos interact with the nucleons through the weak charged current, resulting into absorption, and the weak neutral current, which provides a redistribution of the neutrino energy. We Mellin transform the

T. Gehrmann, W. J. Stirling

It has recently been shown that a new neutral vector boson $Z'$, with a mass of order 1~TeV and weak couplings to quarks only, could explain both the anomalous values of $R_b$ and $R_c$ and the apparent excess of large $E_T$ jet events measured by the CDF collaboration. We calculate the effects of $Z'$ exchange on the $t\bar{t}$ production cross sect

G. Barenboim, J. Bernabeu

We show that it is possible to obtain spontaneous CP violation in the minimal $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, i.e. in a left right symmetric model containing a bidoublet and two triplets in the scalar sector. For this to be a natural scenario, the non-diagonal quartic couplings between the two scalar triplets and the bidoublet play a fundamental

Jiro Kodaira, Yoshiaki Yasui, Kazuhiro Tanaka, Tsuneo Uematsu

We investigate the renormalization of the twist-3 operators which are relevant for the spin-dependent structure function $g_{2}(x, Q^{2})$. We derive the anomalous dimension for the non-singlet part by calculating the off-shell Green's functions of the twist-3 operators including the operators which are proportional to the equation of motion.

Tsuneo Uematsu

We discuss the QCD effects of the higher-twist operators in the nucleon spin-dependent structure functions measured by the polarized deep inelastic leptoproduction. We particularly study the renormalization of the twist-3 and twist-4 operators within the framework of operator product expansions and renormalization group methods in perturbative QCD. Emphasis

G. M. de Divitiis, R. Frezzotti, M. Masetti, R. Petronzio

A method based on the Monte Carlo inversion of the Dirac operator on the lattice provides low noise results for the correlations entering the definition of the heavy meson decay constant in the static limit. The method is complementary to the usual method of smeared sources, avoids the systematic error arising from optimizing the size of the smearing volume

Robert D. Mawhinney

We have measured the valence pion mass and the valence chiral condensate on lattice configurations generated with and without dynamical fermions. We find that our data and that of others is well represented by a linear relationship between $m_π^2$ and the valence quark mass, with a non-zero intercept. For our data, we relate the intercept to finite volume ef

Adriano Di Giacomo, Enrico Meggiolaro, Haralambos Panagopoulos

We study by numerical simulations on a lattice the behaviour of the gauge--invariant two--point correlation functions of the gauge field strengths across the deconfinement phase transition.

Kirill A. Bronnikov, Julio C. Fabris

On the basis of exact solutions to the Einstein-Abelian gauge-dilaton equations in $D$-dimensional gravity, the properties of static axial configurations are discussed. Solutions free of curvature singularities are selected; they can be attributed to traversible wormholes with cosmic string-like singularities at their necks. In the presence of an electromagn

Yu. P. Rybakov, B. Saha, G. N. Shikin

Exact droplet-like solutions to the nonlinear scalar field equations have been obtained in the Robertson-Walker space-time and their linearized stability has been proved.

R. Alvarado, Yu. P. Rybakov, B. Saha, G. N. Shikin

Self-consistent solutions to the system of spinor and scalar field equations in General Relativity are studied for the case of Bianchi type-I space-time. It should be emphasized the absence of initial singularity for some types of solutions and also the isotropic mode of space-time in some special case.

G. Fodor, K. Nakamura, Y. Oshiro, A. Tomimatsu

A definition of surface gravity at the apparent horizon of dynamical spherically symmetric spacetimes is proposed. It is based on a unique foliation by ingoing null hypersurfaces. The function parametrizing the hypersurfaces can be interpreted as the phase of a light wave uniformly emitted by some far-away static observer. The definition gives back the accep

J. Garcia-Ojalvo, J. M. Sancho

The effect of external fluctuations on the formation of spatial patterns is analysed by means of a stochastic Swift-Hohenberg model with multiplicative space-correlated noise. Numerical simulations in two dimensions show a shift of the bifurcation point controlled by the intensity of the multiplicative noise. This shift takes place in the ordering direction

K. M. Frahm, P. W. Brouwer, J. A. Melsen, C. W. J. Beenakker

A theory is presented for the statistics of the excitation spectrum of a disordered metal grain in contact with a superconductor. A magnetic field is applied to fully break time-reversal symmetry in the grain. Still, an excitation gap of the order of $δ$ opens up provided $NΓ^2\gtrsim 1$. Here $δ$ is the mean level spacing in the grain, $Γ$ the tunnel probab

Jean Bricmont

I try to clarify several confusions in the popular literature concerning chaos, determinism, the arrow of time, entropy and the role of probability in physics. Classical ideas going back to Laplace and Boltzmann are explained and defended while some recent views on irreversibility, due to Prigogine, are criticized.

Yu. P. Rybakov, B. Saha

It is shown that the Maxwell's equations for surface electromagnetic TM-waves, propagating along the plane boundary between two nonlinear dielectrics with arbitrary diagonal tensor of dielectric permittivity, depending of |{\bf E}|, can be integrated in quadrature.

A. A. Apolonsky, S. A. Babin, A. I. Chernykh, S. I. Kablukov

CW generation of anti-Stokes Raman laser on a number of blue-green argon-ion lines (4p-4s, 4p-3d) has been demonstrated with optical pumping from metastable levels 3d'^2G, 3d^4F. It is found, that the population transfer rate is increased by a factor of 3-5 (and hence, the output power of such Raman laser) owing to Coulomb diffusion in the velocity space

Victor Andersen

A study of the distribution of barred and nonbarred disk galaxies in the Virgo cluster is presented in an attempt to use the frequency and spatial distribution of galaxies with specific morphological features to study the efficiency of various environmental effects on the evolution of disk galaxies in clusters. The velocity distribution of the barred spirals

M. Pohl, A. Muecke, W. Reich, P. Reich

Starting in 1991 we have performed a regular monitoring of EGRET sources with the Effelsberg 100-m telescope and the IRAM 30-m at Pico Veleta. In comparison with data on a sample of flat-spectrum quasars which have not been seen by EGRET we search for correlations of any kind in the behaviour of FSRQ's in the radio and gamma-ray regime. While there is no

A. Burkert, Y. Yoshii

A new solution is presented for the puzzling, observed universality of the exponential luminosity profiles, perpendicular to the disk plane of spiral and lenticular galaxies. It is shown that such exponential $z$-profiles result naturally from gaseous protodisks which settle into isothermal equilibrium prior to star formation. Subsequent cooling leads to a g

Fuguang Cao, T. Huang

Including corrections of order $O(m_{K^*}/m_B)$, we present an analysis of photonic penguin contributions to the decay $B\to K^* γ$ in the perturbative QCD framework. Employing several models of the meson wave functions, we demonstrate that the corrections of $O(m_{K^*}/m_B)$ are enhanced and will providesubstantial contributions to the decay because of the

G. Degrassi, P. Gambino, A. Vicini

The O(alpha^2 mt^2/mw^2) correction to the relation between G_μand the vector boson masses is computed in the MSbar scheme, and the results are used to investigate the magnitude of the effect on the theoretical prediction of mw and sin^2θ_\msbar(mz) from alpha, G_μ, and mz.

Paul H. Frampton, Otto C. W. Kong

Recent interest in horizontal symmetry model building has been driven mainly by the large top mass and hence strong hierarchy in quark masses, and the possibility of appropriately constrained soft squark mass matrices, in place of an assumed universality condition, for satisfying the relevant FCNC constraints. Here we present the first successful SUSY-$SU(5)

Paul H. Frampton, Otto C. W. Kong

By studying symmetric mass textures for the up and down quark sectors, and expanding in a small parameter $λ\sim sinθ_C$, bounds are set on entries commonly assumed to vanish. Consequences of a 2 + 1 family structure which can result from horizontal symmetry are examined. Generalizing to squarks, we study suppression of Flavor Changing Neutral Currents by ma

Paul Watts

A gauge theory with an underlying SU_q(2) quantum group symmetry is introduced, and its properties examined. With suitable assumptions, this model is found to have many similarities with the usual SU(2)\times U(1) Standard Model, specifically, the existence of four generators and thus four gauge fields. However, the two classical symmetries are unified into

E. Roulet, S. Mollerach

Microlensing observations have now become a useful tool in searching for non--luminous astrophysical compact objects (brown dwarfs, faint stars, neutron stars, black holes and even planets). Originally conceived for establishing whether the halo of the Galaxy is composed of this type of objects, the ongoing searches are actually also sensitive to the dark co

P. Bozek

We present the solution of the time development of an unstable initial density perturbation in the linearized Vlasov equation, completing the previous analysis in the literature. The additional contributions found are usually damped and can be neglected at large times in the unstable region. The work clarifies also the problem of the normalization of the sol

H. M. P. Couchman, F. R. Pearce, P. A. Thomas

A revised version of Hydra, an adaptive particle-particle, particle-mesh plus smoothed particle hydrodynamics code developed by; Hugh Couchman, University of Western Ontario, Frazer Pearce, University of Durham, Peter Thomas, University of Sussex, is now available as a tar file from; http://coho.astro.uwo.ca/pub/hydra/hydra.html or http://star-www.maps.susx.

F. W. Nijhoff, V. B. Kuznetsov, E. K. Sklyanin, O. Ragnisco

The classical r-matrix structure for the generic elliptic Ruijsenaars-Schneider model is presented. It makes the integrability of this model as well as of its discrete-time version that was constructed in a recent paper manifest.

J. L. Forest, V. R. Pandharipande, Steven C. Pieper, R. B. Wiringa

The two-nucleon density distributions in states with isospin $T=0$, spin $S$=1 and projection $M_S$=0 and $\pm$1 are studied in $^2$H, $^{3,4}$He, $^{6,7}$Li and $^{16}$O. The equidensity surfaces for $M_S$=0 distributions are found to be toroidal in shape, while those of $M_S$=$\pm$1 have dumbbell shapes at large density. The dumbbell shapes are generated b

G. Kortemeyer, M. T. Pena, P. U. Sauer, A. Stadler

The pion-nucleon interaction in the P33 partial wave is assumed to proceed simultaneously through the excitation of the Delta-isobar and through a phenomenologically introduced non-resonant background potential. The introduction of the background potential allows a more realistic parameterization of the pion-nucleon-Delta vertex compared with the previously

A. Staszczak, Z. Lojewski

Using the multidimensional dynamic--programming method (MDPM) in the four--dimensional deformation space $\{β_λ\}$ with $λ$=2, 4, 35 and 6 we were able to study evolution of the action integral for the fissioning nucleus $^{258}$Fm. We found the second minimum on the cross--section of the action integral for $β_2 \approx 1$ , what we interpret as the dynamic

A. Staszczak, Z. Lojewski

We study the role of different collective degrees of freedom in spontaneous fission process of even--even Fm isotopes. To find a proper collective space we examine a reach collection of nuclear shape parameters $\{β_λ\}$, with $λ$=2,3,4,5,6 and 8; as well as the paring degrees of freedom i.e. proton $Δ_{p}$ and neutron $Δ_{n}$ pairing gaps. On the basis of t

R. M. Davidson, G. I. Poulis

We revisit sidewise dispersion relations as a method to relate the nucleon off-shell form factor to observable quantities, namely the meson-nucleon scattering phase shifts. It is shown how for meson-nucleon scattering a redefinition of the intermediate fields leaves the scattering amplitude invariant, but changes the behavior of the off-shell form factor as

M. Anguiano, A. M. Lallena, G. Co'

We present calculations of the quasi-elastic responses functions in 4He based upon a mean-field model used to perform analogous calculations in heavier nuclei. The meson exchange current contribution is small if compared with the results of calculations where short-range correlations are explicitly considered. It is argued that the presence of these correlat

Petr Horava, Edward Witten

In this paper, we present a systematic analysis of eleven-dimensional supergravity on a manifold with boundary, which is believed to be relevant to the strong coupling limit of the $E_8\times E_8$ heterotic string. Gauge and gravitational anomalies enter at a very early stage, and require a refinement of the standard Green-Schwarz mechanism for their cancell

Masako Kawamura, Shin'ichi Nojiri, Akio Sugamoto

When the swimming of micro-organisms is viewed from the string and membrane theories coupled to the velocity field of the fluid, a number of interesting results are derived; 1) importance of the area (or volume) preserving algebra, 2) usefulness of the $N$-point Reggeon (membranic) amplitudes, and of the gas to liquid transition in case of the red tide issue

Shin'ichi Nojiri

We investigate the non-abelian $T$-duality of Wess-Zumino-Witten model. The obtained dual model is equivalent to the model dual to the $SU(2)$ chiral model found by Curtright-Zachos. This might tell that the Wess-Zumino term would be induced when the chiral model couples with gravity.

Somenath Chakrabarty

The expulsion of magnetic flux lines from a growing superconducting core of a quark star has been investigated using the idea of impurity diffusion in molten alloys. The possibility of Mullins-Sekerka normal-superconducting interface instability has also been studied.

Somenath Chakrabarty

The effect of strong magnetic field on the stability and gross properties of bulk as well as quasi-bulk quark matter has been investigated using the conventional MIT bag model. Both the Landau diamagnetism and the paramagnetism of quark matter has been studied. How the quark hadron phase transition is affected by the presence of strong magnetic field has als

T. Csorgo, P. Levai, B. Lorstad

This study is devoted to a detailed numerical testing of the analytical results obtained recently for the $M_t$-scaling of the parameters of the Bose-Einstein correlation functions. Numerical testing of analytical results for the spectrum is also performed, since the geometrical sizes are folded into the momentum distribution in the scaling limiting case. Th

M. Carena

I briefly summarize the main features related to the unification of gauge and Yukawa couplings in the MSSM, emphasizing the predictions derived in this framework, which are of special interest in the light of present and near--future experiments

Salvatore Esposito, Pietro Santorelli

We describe a geometric picture for the pattern of fermion masses of the three generations which is invariant with respect to the renormalization group below the electroweak scale. Moreover, we predict the upper limit for the ratio between the Dirac masses of the $μ$ and $τ$ neutrinos, $m_{ν_μ}/ m_{ν_τ} < (9.6 \pm 0.6) 10^{-3}$.

Adriano Di Giacomo, Enrico Meggiolaro, Haralambos Panagopoulos

We determine by numerical simulations on a lattice the gauge--invariant two--point correlation function of the gauge field strengths in the QCD vacuum, down to a distance of 0.1 fm.

Colin Morningstar, Marvin Weinstein

The COntractor REnormalization group (CORE) method, a new approach to solving Hamiltonian lattice systems, is presented. The method defines a systematic and nonperturbative means of implementing Kadanoff-Wilson real-space renormalization group transformations using cluster expansion and contraction techniques. We illustrate the approach and demonstrate its e

Gerhard Rein

We consider the Vlasov-Poisson system in a cosmological setting and prove nonlinear stability of homogeneous solutions against small, spatially periodic perturbations in the sup-norm of the spatial mass density. This result is connected with the question of how large scale structures such as galaxies have evolved out of the homogeneous state of the early uni

Yu. P. Rybakov, B. Saha, G. N. Shikin

It is shown, for the self-consistent system of scalar, electro-magnetic and gravitational fields in general relativity, that the equations of motion admit a special kind of solutions with spherical or cylindrical symmetry. For these solutions, the physical fields vanish and the space-time is flat outside of the critical sphere or cylinder. Therefore, the mas

Douglas Singleton

Several exact, cylindrically symmetric solutions to Einstein&#39;s vacuum equations are given. These solutions were found using the connection between Yang-Mills theory and general relativity. Taking known solutions of the Yang-Mills equations (e.g. the topological BPS monopole solutions) it is possible to construct exact solutions to the general relativisti

D. S. Dean, I. T. Drummond, R. R. Horgan

We investigate the relationship between the effective diffusivity and effective drift of a particle moving in a random medium. The velocity of the particle combines a white noise diffusion process with a local drift term that depends linearly on the gradient of a gaussian random field with homogeneous statistics. The theoretical analysis is confirmed by nume

J. J. Alonso, H. J. Herrmann

We study the shape of the tail of a heap of granular material. A simple theoretical argument shows that the tail adds a logarithmic correction to the slope given by the angle of repose. This expression is in good agreement with experiments. We present a cellular automaton that contains gravity, dissipation and surface roughness and its simulation also gives

Stephen J. Cornell, Alan J. Bray

The low-temperature coarsening dynamics of a one-dimensional Ising model, with conserved magnetisation and subject to a small external driving force, is studied analytically in the limit where the volume fraction μof the minority phase is small, and numerically for general μ. The mean domain size L(t) grows as t^{1/2} in all cases, and the domain-size distri

S. Sorella, A. Parola

Conformal field theory and Bethe ansatz are used to investigate the low energy features of the spectral function in one dimensional models which exhibit a gap in the spin or in the charge excitation spectrum. Exotic behavior is found in the superconducting case, where the Green function displays momentum dependent Luttinger Liquid exponents. The predictions

C. A. Piguet, D. F. Wang, C. Gruber

In this work, we study some general property of a strongly correlated electron system defined on a lattice. Assuming that the lattice system exhibits off-diagonal long range order, we show rigorously that this assumption would lead to Meissner effect. This generalizes previous results of continuous case to a lattice electron system.

V. M. Dubovik, M. A. Martsenyuk, B. Saha

Development of quantum engineering put forward new theoretical problems. Behavior of a single mesoscopic cell (device) we may usually describe by equations of quantum mechanics. However if experimentators gather hundreds of thousands of similar cells there arises some artificial medium that one already needs to describe by means of new electromagnetic equati

N. Argaman, A. Zee

The planar-diagrammatic technique of large-$N$ random matrices is extended to evaluate averages over the circular ensemble of unitary matrices. It is then applied to study transport through a disordered metallic ``grain&#39;&#39;, attached through ideal leads to a normal electrode and to a superconducting electrode. The latter enforces boundary conditions wh

Kristinn Johnsen, Jakob Yngvason

We report on a numerical study of the density matrix functional introduced by Lieb, Solovej and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes {\em exactly} the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge $Z$ and the electron number $N$ tend to infinity with $N/Z$ fi

Yu. P. Rybakov, B. Saha

The Einstein - de Broglie particle-soliton concept is applied to simulate stationary states of an electron in a hydrogen atom. According to this concept, the electron is described by the localized regular solutions to some nonlinear equations. In the framework of Synge model for interacting scalar and electromagnetic fields a system of integral equations has

G. H. Moriarty-Schieven, T. Xie, N. A. Patel

IC 1396 is a relatively nearby (750 pc), large (>2 deg), HII region ionized by a single O6.5V star and containing bright-rimmed cometary globules. We have made the first arcmin resolution images of atomic hydrogen toward IC 1396, and have found remarkable ``tail&#39;&#39;-like structures associated with some of the globules and extending up to 6.5 pc radiall

S. Kuznetsov, M. Gilfanov, E. Churazov, R. Sunyaev

The entire dataset of the GRANAT/SIGMA observations of Cyg X-1 and 1E1740.7-294 in 1990-1994 was analyzed in order to search for correlations between primary observational characteristics of the hard X-ray emission - hard X-ray luminosity L_X, hardness of the spectrum (quantified in terms of the best fit thermal bremsstrahlung temperature kT) and the RMS of

Sandip K. Chakrabarti

We study time evolution and gravitational wave emission properties of a black hole orbiting {\it inside} an accretion disk surrounding a massive black hole. We simultaneously solve the structure equations of the accretion disk in presence of heating, cooling and viscosity as well as the equations governing the companion orbit. The deviation from Keplerian di

Stuart Lumsden, Phil Puxley

We present complete, low resolution IJHK spectroscopy of the ultracompact HII region, G45.12+0.13. From the observed HI line strengths, we derive a near infrared extinction law that is slightly steeper than the average. After correction with this extinction law, we find good agreement between the observed line ratios of HeI, Fe+, Fe++, S+ and S++ and the ava

Stuart Lumsden, Melvin Hoare

We have mapped the velocity structure of the cometary compact HII region G29.96-0.02 using long-slit echelle spectra of the HI Br gamma line. This technique detects line emission over a much wider area at the necessary spatial resolution compared to radio recombination line observations. Significant structure in both the velocity centroids and the line width

Lawrence Ein, Robert Lazarsfeld

The purpose of this paper is to show how the generic vanishing theorems of M. Green and the second author can be used to settle several questions and conjectures concerning the geometry of irregular complex projective varieties. First, we prove a conjecture of Arbarello and DeConcini characterizing principally polarized abelian varieties whose theta divisors

Jean-Marc Drézet

A transformation of morphisms of sheaves, called mutation, is used to build new moduli spaces of morphisms.

Geir Ellingsrud, Stein Arild Strømme

Let S be a smooth projective surface, and consider the following two subvarieties of the Hilbert scheme parameterizing closed subschemes of S of length n: A = {subschemes with support in a fixed point of S} B = {subschemes with support in one (variable) point of S} A and B have complementary dimensions in the Hilbert scheme. We prove that the intersection nu

D. C. Cabra, E. F. Moreno

We study the $SU(2)_k/U(1)$-parafermion model perturbed by its first thermal operator. By formulating the theory in terms of a (perturbed) fermionic coset model we show that the model is equivalent to interacting WZW fields modulo free fields. In this scheme, the order and disorder operators of the $Z_k$ parafermion theory are constructed as gauge invariant

Sergei V. Zenkin

An ansatz for the fermion vacuum functional on a lattice is proposed. It is proved to reproduce correct continuum limit for convergent diagrams of any finite order in smooth external fields, as well as consistent chiral anomalies, and ensures gauge invariance of the absolute value of the functional at any lattice spacing. The ansatz corresponds to a certain

N. Persky, R. Ben-Av, I. Kanter, E. Domany

The dynamic behavior of cluster algorithms is analyzed in the classical mean field limit. Rigorous analytical results below $T_c$ establish that the dynamic exponent has the value $z_{sw}=1$ for the Swendsen-Wang algorithm and $z_{uw}=0$ for the Wolff algorithm. An efficient Monte Carlo implementation is introduced, adapted for using these algorithms for ful

S. Peris, E. de Rafael

It is shown that the commonly accepted relationship between the Landau singularity in the running coupling constant of QED or QCD and the renormalon singularities in the Borel sums of perturbation theory expansions is only a particular feature of the restriction of the perturbative $β$--function to the one loop level.

Bernd Ammann

Hedlund constructed Riemannian metrics on n-tori, $n \geq 3$ for which minimal geodesics are very rare. In this paper we construct similar examples for every nilpotent fundamental group. These examples show that Bangert&#39;s existence results of minimal geodesics are optimal for nilpotent fundamental groups.

N. Dorey, V. V. Khoze, M. P. Mattis

The Seiberg-Witten solution of N=2 supersymmetric SU(2) gauge theory may be viewed as a prediction for the infinite family of constants F_n measuring the n-instanton contribution to the prepotential F. Here we examine the instanton physics directly, in particular the contribution of the general self-dual solution of topological charge n constructed by Atiyah

Martin Cederwall, Magnus Holm

We derive parts of the monopole and dyon spectra for N=2 super-Yang--Mills theories in four dimensions with gauge groups G of rank r>1 and matter multiplets. Special emphasis is put on G=SU(3) and those matter contents that yield perturbatively finite theories. There is no direct interpretation of the soliton spectra in terms of naive selfduality under stron

Christian Y. Cardall, George M. Fuller

Studies of limits on active-sterile neutrino mixing derived from big bang nucleosynthesis considerations are extended to consider the dependance of these constraints on the primordial deuterium abundance. This study is motivated by recent measurements of D/H in quasar absorption systems, which at present yield discordant results. Limits on active-sterile mix

Maximo Banados

We study the problem of boundary terms and boundary conditions for Chern-Simons gravity in five dimensions. We show that under reasonable boundary conditions one finds an effective field theory at the four-dimensional boundary described by dilaton gravity with a Gauss-Bonnet term. The coupling of matter is also discussed.

Masahisa Matsuda, Tsuyoshi B. Suzuki

We study the semileptonic branching fraction of $B$-meson into higher resonance of charmed meson $D^{**}$ by using the Bjorken sum rule and the heavy quark effective theory(HQET). This sum rule and the current experiment of $B$-meson semileptonic decay into $D$ and $D^*$ predict that the branching ratio into $D^{**}lν_l$ is about 1.7\%. This predicted value