October 1994 arXiv papers — page 6

A. H. Bilge, M. Hortacsu, N. Ozdemir

The role of the identification of the vacuum and non-vacuum space-times in the computation of vacuum fluctuations in the presence of a cosmic string is discussed and an alternative interpretation of the renormalization is proposed. This procedure does not give rise to vacuum fluctuations.

S. Carlip, J. Gegenberg, R. B. Mann

We investigate the black hole solution to (2+1)-dimensional gravity coupled to topological matter, with a vanishing cosmological constant. We calculate the total energy, angular momentum and entropy of the black hole in this model and compare with results obtained in Einstein gravity. We find that the theory with topological matter reverses the identificatio

A. H. Bilge, M. Hortacsu, N. Ozdemir

We calculate the Bogolubov coefficients for a metric which describes the snapping of a cosmic string. If we insist on a matching condition for all times {\it and} a particle interpretation, we find no particle creation.

Karl-Peter Marzlin

The dipole coupling term between a system of N particles with total charge zero and the electromagnetic field is derived in the presence of a weak gravitational field. It is shown that the form of the coupling remains the same as in flat space-time if it is written with respect to the proper time of the observer and to the measurable field components. Some r

Marek Bozejko, Michael Leinert, Roland Speicher

We introduce the notion of a conditionally free product and conditionally free convolution. We describe this convolution both from a combinatorial point of view, by showing its connection with the lattice of non-crossing partitions, and from an analytic point of view, by presenting the basic formula for its $R$-transform. We calculate explicitly the distribu

S. P. Strong

I give a simple general prescription for computing the spectral functions of local operators in the Tomonaga-Luttinger model from the space-time correlation functions. The method is significantly simpler than directly transforming the space-time Greens function and allows a physical interpretation of the singularities encountered in the spectral function.

Dante R. Chialvo, Mark M. Millonas

It has been shown that the combination of a broken spatial symmetry in the potential (or ratchet potential) and time correlations in the driving are crucial, and enough to allow transformation of the fluctuations into work. The required broken spatial symmetry implies a specific molecular arrangement of the proteins involved. Here we show that a broken spati

Mark I. Dykman, Mark M. Millonas, Vadim N. Smelyanskiy

We study local features, and provide a topological insight into the global structure of the probability density distribution and of the pattern of the optimal paths for large rare fluctuations away from a stable state. In contrast to extremal paths in quantum mechanics, the optimal paths do {\it not} encounter caustics. We show how this occurs, and what, ins

Mark M. Millonas

A Maxwell's demon type ``information engine" which extracts work from a bath is constructed from a microscopic Hamiltonian for the whole system including a subsystem, a thermal bath, and a nonequilibrium bath of phonons or photons which represents an information source/sink. The kinetics of the engine is calculated self-consistently from the state of

S. L. A. de Queiroz

The two-dimensional random-bond Ising model is numerically studied on long strips by transfer-matrix methods. It is shown that the rate of decay of correlations at criticality, as derived from averages of the two largest Lyapunov exponents plus conformal invariance arguments, differs from that obtained through direct evaluation of correlation functions. The

Kasper Eriksen, Yang Chen

Eigenvalue correlations of random matrix ensembles as a function of an external perturbation are investigated vis the Dyson Brownian Motion Model in the situation where the level density has a hard edge singularity. By solving a linearized hydrodynamical equation, a universal dependence of the density-density correlator on the external field is found. As an

H. Waelbroeck

We examine an 11-year data set from the tropical weather station of Tlaxcala, Mexico. We find that mutual information drops quickly with the delay, to a positive value which relaxes to zero with a time scale of 20 days. We also examine the mutual dependence of the observables and conclude that the data set gives the equivalent of 8 variables per day, known t

Sharon L. Vadas

In this paper, we study the collapse of a superhorizon-sized void in the early, radiation-dominated universe using an improved general relativistic code. We find that in general a relativistic or nonrelativistic void collapses via a shock at the speed of light. This is true even if the outward velocity of the void wall is enormous. As the wall thickness decr

J. B. Hutchings, D. Crampton, Andrea Johnson

We discuss broad- and narrow-band imaging of 7 arcmin fields of 14 QSOs with redshift ~1.1. The narrow-band filters were chosen to detect redshifted [O II] 3727A, and the broad bands are R and I, which correspond to rest wavelengths {}~3300A and ~3800A. In 100 arcsec subfields surrounding the QSOs, we detect an excess of typically 15 detected objects over th

C. D. Levermore, W. Nadler, D. L. Stein

We study the problem of a random walk on a lattice in which bonds connecting nearest neighbor sites open and close randomly in time, a situation often encountered in fluctuating media. We present a simple renormalization group technique to solve for the effective diffusive behavior at long times. For one-dimensional lattices we obtain better quantitative agr

S. W. Chan, H. F. Chau

We prove a necessary and sufficient condition for an Abelian Sandpile Model (ASM) to be avalanche-finite, namely: all unstable states of the system can be brought back to stability in finite number of topplings. The method is also computationally feasible since it involves no greater than $\mbox{O} \left( N^3 \right)$ arithmetic computations where $N$ is the

Bergfinnur Durhuus, Thordur Jonsson

We give a simple combinatoric proof of an exponential upper bound on the number of distinct 3-manifolds that can be constructed by successively identifying nearest neighbour pairs of triangles in the boundary of a simplicial 3-ball and show that all closed simplicial manifolds that can be constructed in this manner are homeomorphic to $S^3$. We discuss the p

A M Semikhatov

It is well known that many interesting realisations of string theories can be obtained via hamiltonian reduction from WZW models. I want to point out that string theories do in certain cases also provide the recipe to reconstruct the ambient space of the hamiltonian reduction, including Kac--Moody currents and the associated ghosts. The procedure of reconstr

G. Sardanashvily

The familiar generating functionals in QFT fail to be true measures since the Lebesgue measure in infinite-dimensional spaces is not defined in general. The problem lies in constructing representations of topological $^*$-algebras of quantum fields which are not normed. We restrict our consideration only to chronological forms on quantum field algebras. In t

E. Boridy, C. Hamzaoui, F. Lemay, J. Lindig

We investigate in detail a modified version of the Fritzsch scheme where the diagonal entries $(M_{u,d})_{22}$ are introduced as free parameters instead of being zero. We find that $(M_u)_{22}$ and $(M_d)_{22}$ are restricted to l in the range $m_u-m_c\leq (M_u)_{22}< m_t-m_c$ and $m_d-m_s\leq (M_d)_{22}< m_b-m_s$. In the context of this scheme, we obtain th

Mohammad R. Ahmady, Roberto R. Mendel, James D. Talman

We use the Dirac equation with a ``(asymptotically free) Coulomb + (Lorentz scalar) linear &#39;&#39; potential to estimate the light quark wavefunction for $ q\bar Q$ mesons in the limit $m_Q\to \infty$. We use these wavefunctions to calculate the Isgur-Wise function $ξ(v.v^\prime )$ for orbital and radial ground states in the phenomenologically interesting

Vakhtang Kartvelishvili, Murman Margvelashvili

The difference of tau partial decay widths into even and odd number of pions may be considered as another important constraint on the hadronic spectral function, in addition to four classic sum rules of current algebra. Within certain reasonable assumptions its value may be used to test the factorization hypothesis and estimate the contribution of dimension

Alexander Reznikov

We prove that there exists a metric of positive curvature in a three-sphere which admits a given torus knot as a closed geodesic.We also sketch a construction of a metric in a four sphere, very likely of positive curvature, which admits a totally geodesic projective plane with Euler number four. Surpisingly, the technique borrows a lot from the Mostow-Siu-Gr

Yang Wang, C. H. Mak

A transferable tight-binding potential has been constructed for heteroatomic systems containing carbon and hydrogen. The electronic degree of freedom is treated explicitly in this potential using a small set of transferable parameters which has been fitted to small hydrocarbons and radicals. Transferability to other higher hydrocarbons were tested by compari

C. H. Mak, Reinhold Egger

We present a detailed analysis of the mechanism of the primary charge separation process in bacterial photosynthesis using real-time path integrals. Direct computer simulations as well as an approximate analytical theory have been employed to map out the dynamics of the charge separation process in many regions of the parameter space relevant to bacterial ph

Takashi Kimura, Alexander A. Voronov

The purpose of this paper is to introduce the cohomology of various algebras over an operad of moduli spaces including the cohomology of conformal field theories (CFT&#39;s) and vertex operator algebras (VOA&#39;s). This cohomology theory produces a number of invariants of CFT&#39;s and VOA&#39;s, one of which is the space of their infinitesimal deformations

David P. Bennett, Sun Hong Rhie

The possibility that classical gamma ray bursts (GRB) occasionally repeat from the same locations on the sky provides a critical test of GRB models. There is currently some controversy about whether there is evidence for burst repetition in the BATSE data. We introduce a gamma ray burst ``pair matching" statistic that can be used to search for a repeater sig

Hilmar Forkel

We consider a new approach to the description of dense nuclear matter in the framework of chirally symmetric, quark-based hadron models. As previously in the Skyrme model, the dense environment is described in terms of hyperspherical cells of unit baryon number. The intrinsic curvature of these cells generates a new gauge interaction for the quark fields whi

M. Costantini, M. Varagnolo

We study the theory of representations of a multiparameter deformation of the function algebra of a simple algebraic group (as defined by Reshetikhin) when the quantum parameter is a root of unity. We extend the technics of De Concini-Lyubashenko in the standard quantum case.

K. Matsuki, R. Wentworth

We study the behavior of the Gieseker space of semistable torsion-free sheaves of rank r and fixed c_1, c_2 on a non-singular projective surface as the polarization varies. It is shown that the ample cone admits a locally finite chamber structure, and that passing a wall adjacent to a pair of chambers has the effect of modifying the moduli space by a (finite

B. Blok, R. Dikeman, M. Shifman

We calculate the 1/$m^3_c$ corrections in the inclusive semileptonic widths of $D$ mesons. We show that these are due to the novel penguin type operators that appear at this level in the transition operator. Taking into account the nonperturbative corrections leads to the predicted value of the semileptonic width significantly lower than the experimental val

J. Chýla, J. Rameš

Recently the CCFR Collaboration reported the measurement of the Gross--Llewellyn Smith sum rule %at $Q^2=3\; \mr{GeV}^2$: $\int^{1}_{0}\mr{d}F_{3}^{νp+\bareνp}(x,Q^2=3\;\mr{GeV}^2)= 2.50\pm 0.018(\mr{stat})$. Subsequently Kataev and Sidorov analyzed the $Q^2$--dependence of this sum rule and pointed out a discrepancy between the results obtained via integrat

P L Christiansen, J C Eilbeck, V Z Enolskii, N A Kostov

We consider travelling periodical and quasiperiodical waves in single mode fibres, with weak birefringence and under the action of cross-phase modulation. The problem is reduced to the ``1:2:1" integrable case of the two-particle quartic potential. A general approach for finding elliptic solutions is given. New solutions which are associated with two-gap Tre

Mark Srednicki

If a many-body quantum system approaches thermal equilibrium from a generic initial state, then the expectation value $\langleψ(t)|A_i|ψ(t)\rangle$, where $|ψ(t)\rangle$ is the system&#39;s state vector and $A_i$ is an experimentally accessible observable, should approach a constant value which is independent of the initial state, and equal to a thermal aver

Ioannis Bakas

The S--duality transformations of the lowest order string effective theory admit a space time interpretation for 4-dim backgrounds with one Killing symmetry. Starting from pure gravity and performing a sequence of intertwined T-S-T duality transformations we obtain new solutions which are always pure gravitational. In this fashion, S-duality induces an $SL(2

Claudio Teitelboim

The Hamiltonian actions for extreme and non-extreme black holes are compared and contrasted and a simple derivation of the lack of entropy of extreme black holes is given. In the non-extreme case the wave function of the black hole depends on horizon degrees of freedom which give rise to the entropy. Those additional degrees of freedom are absent in the extr

E. Elizalde, K. Kirsten, Yu. Kubyshin

The 1-loop effective potential in a scalar theory with quartic interaction on the space $M^{4} \times T^{n}$ for $n=2$ is calculated and is shown to be unbounded from below. This is an indication of a possible instability of the vacuum of the $λϕ^{4}$ theory on $M^{4}$, when it is regarded as a result of the dimensional reduction of the original six-dimensio

Laurence Yaffe

Talk presented at the conference Quarks `94: Vladimir, Russia. I summarize the application of $ε$-expansion methods to the electroweak phase transition. Results from both leading and next-to-leading order calculations are discussed.

Peter Arnold

Talk presented at the conference Quarks `94: Vladimir, Russia. I review the successes and limitations of standard perturbative methods for studying the order and strength of the electroweak phase transition.

Peter Filip

Some experimental results of correlation functions in Bose-Einstein interferometry measurements exhibit a non smooth behaviour - oscillations. Possible origin of such a behaviour in non-trivial spatial distribution of the source is considered. A method for obtaining additional information about the structure of source emitting identical particles is suggeste

Ahmed Ali, Gian Giudice, Thomas Mannel

We propose to undertake a model-independent analysis of the inclusive decay rates and distributions in the processes \bgamaxs~ and \Bsell ~($B=B^\pm$ or $B^0_d$). We show how measurements of the decay rates and distributions in these processes would allow us to extract the magnitude and sign of the dominant Wilson coefficients of the magnetic moment operator

Zenrō Hioki

Several different effects in electroweak quantum corrections are explored separately through the latest data on the weak-boson masses. The leading-log approximation, the improved-Born approximation and the non-decoupling top-quark effects are studied without depending on the recent CDF data of $m_t$, and the results are given in a form independent of the Hig

D. Espriu

This is the written version of a set of lectures on perturbative QCD that were delivered to a mixed audience of young theorists and experimentalists in the course of the XXII International Meeting on Fundamental Physics. These notes are virtually a verbatim transcription of the lectures. The selection of topics is somewhat arbitrary, but two basic points are

Frederick T. Hawes, Anthony G. Williams

We present results from a study of subtractive renormalization of the fermion propagator Dyson-Schwinger equation (DSE) in massive strong-coupling quenched QED$_4$. Results are compared for three different fermion-photon proper vertex {\it Ansätze\/}: bare $γ^μ$, minimal Ball-Chiu, and Curtis-Pennington. The procedure is straightforward to implement and nume

Hitoshi Murayama

I review phenomenologically interesting aspects of supersymmetry. First I point out that the discovery of the positron can be regarded as a historic analogue to the would-be discovery of supersymmetry. Second I review the recent topics on the unification of the gauge coupling constants, $m_b$--$m_τ$ relation, proton decay, and baryogenesis. I also briefly di

Jihn E. Kim, Gye T. Park

We explore the one-loop electroweak radiative corrections in the context of the traditional minimal $SU(5)$ and the string-inspired $SU(5)\times U(1)$ supergravity models by calculating explicitly vacuum-polarization and vertex-correction contributions to the $ε_1$ and $ε_b$ parameters. We also include in this analysis the constraint from $b\rightarrow sγ$ w

H. Baer, C. Kao, X. Tata

We evaluate cross sections for $\eslt$, 1$\ell$ and various dilepton and multilepton event topologies that result from the simultaneous production of all sparticles at the Tevatron collider, both within the minimal model framework as well as in two different $R$-parity violating scenarios. Our analysis assumes that these $R$-violating couplings are small, an

M. Otto, T. A. Vilgis

The conformational and electronic properties of conducting flexible random and self-avoiding walk polymer chains are under investigation. A Hamiltonian for conjugated flexible polymers is introduced and its physical consequences are presented. One important result is that the electronic degrees of freedom greatly affect the conformational statistics of the w

M. R. Norman, A. H. MacDonald, H. Akera

We consider magnetic oscillations due to Landau quantization in the mixed state of type-II superconductors. Our work is based on a previously developed formalism which allows the mean-field gap equations of the Abrikosov state to be conveniently solved in a Landau level representation. We find that the quasiparticle band structure changes qualitatively when

A. H. MacDonald

These lecture notes attempt to explain the main ideas of the theory of the quantum Hall effect. The emphasis is on the localization and interaction physics in the extreme quantum limit which gives rise to the quantum Hall effect. The interaction physics in the extreme quantum limit which is responsible for the fractional quantum Hall effect is discussed at l

Peter F. Stadler, Wolfgang Schnabl, Christian V. Forst, Peter Schuster

Mutation is introduced into autocatalytic reaction networks. Examples of low dimensional dynamical systems --- n = 2, 3 and 4 --- are discussed and complete qualitative analysis is presented. Error thresholds known from simple replication-mutation kinetics with frequency independent replication rates occur here as well. Instead of cooperative transitions or

J. C. N. de Araújo, J. A. de Freitas Pacheco, J. E. Horvath, M. Cattani

The prospects for detection of gravitational waves from precessing pulsars have been considered by constructing fully relativistic rotating neutron star models and evaluating the expected wave amplitude $h$ from a galactic source. For a &#34;typical&#34; neutron matter equation of state and observed rotation rates, it is shown that moderate wobble angles may

D. Schaerer, A. de Koter, W. Schmutz

In this paper we present Complete Stellar models (CoStar) for massive stars, which treat the stellar interior and atmosphere, including its wind. Particular emphasis is given to Wolf-Rayet stars. We address the question of the effective temperatures of WNE and WC stars. Our first results show a satisfactory agreement between the CoStar models and the simple

Chris Mihos

Using a combination of numerical simulation and synthesized Hubble Space Telescope Wide Field Camera 2 (HST WFC2) images, we follow the detectability of morphological signatures of disk galaxy mergers at intermediate redshifts z=0.4 and z=1.0. Rapid evolution in the surface brightness of tidal tails makes their use as an interaction signature limited; long t

K. Z. Stanek, M. Mateo, A. Udalski, M. Szymanski

The Optical Gravitational Lensing Experiment (OGLE, Udalski et al.~1994a; Paczyński et al.~1994b -- these proceedings; and references therein) is an extensive photometric search for the rare cases of gravitational microlensing of Galactic bulge stars by foreground objects. It provides a huge data base (Szymański \& Udalski 1993), from which color-magnitude d

Simon D. M. White

This is a set of lecture notes based on the lectures on the formation and evolution of galaxies which were given by S. White at Les Houches in August 1993. This postscript file does not contain the 16 figures. A version containing these figures can be obtained by writing to: Fr. C. Rickl, MPI fuer Astrophysik, Karl-Schwarzschildstr. 1, 85740 Garching, German

Bert van Geemen, Emma Previato

The Hitchin system is a completely integrable hamiltonian system (CIHS) on the cotangent space to the moduli space of semi-stable vector bundles over a curve. We consider the case of rank-two vector bundles with trivial determinant. Such a bundle $E$ defines a divisor $D_E$ in the Jacobian of the curve and for any smooth point of $D_E$ we define a cotangent

Michael Joyce, Tomislav Prokopec, Neil Turok

We investigate baryogenesis at a first order electroweak phase transition in the presence of a CP violating condensate on the bubble walls, in the regime in which the bubble walls are `thick', in the sense that fermions interact with the plasma many times as the bubble wall passes. Such a condensate is present in multi-Higgs extensions of the standard model

Michael G. Schmidt, Christian Schubert

We use the worldline path-integral approach to the Bern-Kosower formalism for developing a new algorithm for calculation of the sum of all diagrams with one spinor loop and fixed numbers of external and internal photons. The method is based on worldline supersymmetry, and on the construction of generalized worldline Green functions. The two-loop QED $β$ -- f

Michael Joyce, Tomislav Prokopec, Neil Turok

We investigate `non-local' schemes for baryogenesis at a first order electroweak phase transition, in which the effects of a $CP$ violating condensate on the bubble wall propagate into the unbroken phase where the sphaleron rate is unsupressed. Such a condensate exists in multi-Higgs extensions of the standard model, and may exist due to an instability in th

N. B. Shul&#39;gina

The recent experimental results on deep inelastic polarized lepton scattering off proton, deuteron and $^{3}$He together with polari% zed neutron $β$-decay data are analyzed. It is shown that the problem of Ellis-Jaffe and Bjorken sum rules deficiency and the neutron paradox could be solved simultaneously by assuming the small right handed current (RHC) admi

P. Baird, J. C. Wood

We construct new complex-valued harmonic morphisms from Euclidean spaces from functions which are holomorphic with respect to Hermitian structures. In particular, we give the first global examples of complex-valued harmonic morphisms from ${\bf R}^n$ for each $n>4$ which do not arise from a Kähler structure; it is known that such examples do not exist for $n

Fernando Martinez-Moras, Javier Mas

It is well known that the centerless W_{1+\infty} algebra provides a hamiltonian structure for the KP hierarchy. In this letter we address the question whether the centerful version plays a similar rôle in any related integrable system. We find that, surprisingly enough, the centrally extended W_{1+\infty} algebra yields yet another Poisson structure for the

Anastasios Petkou

We discuss conserved currents and operator product expansions (OPE&#39;s) in the context of a $O(N)$ invariant conformal field theory. Using OPE&#39;s we find explicit expressions for the first few terms in suitable short-distance limits for various four-point functions involving the fundamental $N$-component scalar field $ϕ^α(x)$, $α=1,2,..,N$. We propose a

D. Ivanov

Knizhnik-Zamolodchikov-Bernard equations for twisted conformal blocks on compact Riemann surfaces with marked points are written explicitly in a general projective structure in terms of correlation functions in the theory of twisted b-c systems. It is checked that on the moduli space the equations provide a flat connection with the spectral parameter.

T. Tachizawa, K. Maeda, T. Torii

We reanalyze the gravitating monopole and its black hole solutions in the Einstein-Yang-Mills-Higgs system and we discuss their stabilities from the point of view of catastrophe theory. Although these non-trivial solutions exhibit fine and complicated structures, we find that stability is systematically understood via a swallow tail catastrophe. The Reissner

Troy Shinbrot, J. M. Ottino

We describe a map-based model which reproduces many of the behaviors seen in partial differential equations (PDE&#39;s). Like PDE&#39;s, we show that this model can support an infinite number of stationary solutions, traveling solutions, breathing solutions, and elastically colliding solutions. Unlike PDE&#39;s, the model can be applied with minimal computat

Rainer Dick

From a geometric point of view, massless spinors in $3+1$ dimensions are composed of primary fields of weights $(\frac{1}{2},0)$ and $(0,\frac{1}{2})$, where the weights are defined with respect to diffeomorphisms of a sphere in momentum space. The Weyl equation thus appears as a consequence of the transformation behavior of local sections of half--canonical

H. Boschi-Filho, C. Farina, A. de Souza Dutra

We compute the partition function of an anyon-like harmonic oscillator. The well known results for both the bosonic and fermionic oscillators are then reobtained as particular cases as ours. The technique we employ is a non-relativistic version of the Green function method used in the computation of one-loop effective actions of quantum field theory.

J. W. Goodison, D. J. Toms

We calculate the canonical partition function $Z_N$ for a system of $N$ free particles obeying so-called `quon&#39; statistics where $q$ is real and satisfies $|q|<1$ by using simple counting arguments. We observe that this system is afflicted by the Gibbs paradox and that $Z_N$ is independent of $q$. We demonstrate that such a system of particles obeys the

Brandon Carter, Ruth Gregory

The most usual procedure for deriving curvature corrections to effective actions for topological defects is subjected to a critical reappraisal. A logically unjustified step (leading to overdetermination) is identified and rectified, taking the standard domain wall case as an illustrative example. Using the appropriately corrected procedure, we obtain a new

M. Hindmarsh, K. Strobl

We investigate numerically the configurational statistics of strings. The algorithm models an ensemble of global $U(1)$ cosmic strings, or equivalently vortices in superfluid $^4$He. We use a new method which avoids the specification of boundary conditions on the lattice. We therefore do not have the artificial distinction between short and long string loops

Haru-Tada Sato, Hisao Suzuki

We discuss the Bogoliubov transformation of the scalar wave functions caused by the change of coordinates in 4 dimensional de Sitter space. It is shown that the exact Bogoliubov coefficients can be obtained from the global coordinates to the static coordinates where there exist manifest horizon. We consider two type of global coordinates. In one global coord

Masako Asano, Chigak Itoi, Shin-Ichi Kojima

A rigorous definition of a path integral for a spinning particle in three dimensions is given on a regular cubic lattice. The critical diffusion constant and the associated critical exponents in each spin are calculated. Continuum field theories such as Klein-Gordon, Dirac and massive Chern-Simons theories are constructed near these critical points. The univ

D. Gepner, A. Kapustin

The fusion rules and modular matrix of a rational conformal field theory obey a list of properties. We use these properties to classify rational conformal field theories with not more than six primary fields and small values of the fusion coefficients. We give a catalogue of fusion rings which can arise for these field theories. It is shown that all such fus

Takashi Suzuki

A possibility of strong coupling quantum Liouville gravity is investigated via infinite dimensional representations of $\qslc$ with $q$ at a root of unity. It is explicitly shown that vertex operator in this model can be written by a tensor product of a vertex operator of the classical Liouville theory and that of weak coupling quantum Liouville theory. Some

V. M. Belyaev, V. M. Braun, A. Khodjamirian, R. Rückl

We calculate the $D^*Dπ$ and $B^*Bπ$ couplings using QCD sum rules on the light-cone. In this approach, the large-distance dynamics is incorporated in a set of pion wave functions. We take into account two-particle and three-particle wave functions of twist 2, 3 and 4. The resulting values of the coupling constants are $g_{D^*Dπ}= 12.5\pm 1$ and $g_{B^*Bπ}=

M. A. Braun

The equation for two reggeized gluons with a running QCD coupling constant, proposed earlier on the basis of the bootstrap condition, is investigated by the variational technique in the vacuum channel. The pomeron intercept and slope are calculated as a function of the infrared cutoff parameter $m$ (&#34;the gluon mass&#34;). The intercept depends weakly on

H. Lew, R. R. Volkas

The low-energy approach to electric charge quantization predicts physics beyond the minimal standard model. A model-independent approach via effective Lagrangians is used examine the possible new physics, which may manifest itself indirectly through family-lepton--number violating rare decays.

Samuel W. MacDowell, Ola Törnkvist

The stability of an abelian (Nielsen-Olesen) vortex embedded in the electroweak theory against W production is investigated in a gauge defined by the condition of a single-component Higgs field. The model is characterized by the parameters $β=({M_H\over M_Z})^2$ and $γ=\cos^2θ_{\rm w}$ where $θ_{\rm w}$ is the weak mixing angle. It is shown that the equation

Shinya Kanemura, Takahiro Kubota

The decay rate of a (neutral) Higgs boson ($H$) going into a longitudinal $W$-boson pair is calculated by including one loop radiative corrections in a two-Higgs doublet model. It is assumed that the Higgs boson $H$ is much heavier than the $W$ boson and a full use has been made of the equivalence theorem. A possibility is explored extensively that the preci

Thomas Kalkreuter

Complete spectra of the staggered Dirac operator $\Dirac$ are determined in four-dimensional $SU(2)$ gauge fields with and without dynamical fermions. An attempt is made to relate the performance of multigrid and conjugate gradient algorithms for propagators with the distribution of the eigenvalues of~$\Dirac$.

John Baez

Recent work on the loop representation of quantum gravity has revealed previously unsuspected connections between knot theory and quantum gravity, or more generally, 3-dimensional topology and 4-dimensional generally covariant physics. We review how some of these relationships arise from a `ladder of field theories&#39; including quantum gravity and BF theor

Parentani Renaud

The inequivalence of thermodynamical ensembles related by a Legendre transformation is manifest in self-gravitating systems and in black hole thermodynamics. Using the Poincare&#39;s method of the linear series, we describe the mathematical reasons which lead to this inequivalence which in turn induces a hierarchy of ensembles: the most stable ensemble descr

Klaus Richter

We derive semiclassical expressions for the Kubo conductivity tensor. Within our approach the oscillatory parts of the diagonal and Hall conductivity are given as sums over contributions from classical periodic orbits in close relation to Gutzwiller&#39;s trace formula for the density of states. Taking into account the effects of weak disorder and temperatur

H. -O. Müller, A. Hädicke, W. Krech

The temperature dependence of the I-V characteristics of many single-electron tunneling devices enable thermometer operation of these systems. We investigate two normal conducting kinds of them, {\sl (a)} a single junction in a high-impedance environment, and {\sl (b)} a double junction. The characteristics of both devices show a crossover from Coulomb block

Ezer Melzer

The dispersion relations and S-matrix of the one-dimensional Hubbard model at half filling are considered in a certain scaling limit. (In the process we derive a useful small-coupling expansion of the exact lattice dispersion relations.) The resulting scattering theory is consistently identified as that of the SU(2) chiral-invariant Thirring (or Gross-Neveu)

Gen Tatara, Hidetoshi Fukuyama

The depinning of a domain wall in ferromagentic metal via macroscopic quantum tunneling is studied based on the Hubbard model. The dynamics of the magnetization verctor is shown to be governed by an effective action of Heisenberg model with a term non-local in time that describes the dissipation due to the conduction electron. Due to the existence of the Fer

T. J. Davidge

Deep V and I CCD images with sub-arcsec spatial resolution are used to investigate the stellar content of the central regions of the Local Group dwarf elliptical galaxy NGC147. Red giant branch (RGB) stars are resolved over the entire field, and the RGB-tip occurs at I ~ 20.5, suggesting that the distance modulus is 24.3. A comparison with globular cluster s

C. L. Morbey, O. Le Fevre, F. Hammer, L. Tresse

In the course of the comprehensive CFRS redshift survey to I = 22.5 with the CFHT MOS/SIS spectrograph, we have observed ~25 field galaxies with z > 1. However, it is clear that almost an equal number, predominantly red galaxies, have likely been missed largely because of limitations in the observed wavelength range. The properties of the observed galaxies a

K. M. Lanzetta, D. V. Bowen, D. Tytler, J. K. Webb

We present initial results of an imaging and spectroscopic survey of faint galaxies in fields of Hubble Space Telescope spectroscopic target QSOs. The primary objectives of the survey are (a) to determine the incidence, extent, and covering factor of extended gaseous envelopes of luminous galaxies and (b) to determine the fraction of Lyman alpha absorption s

Arthur Mezhlumian

This is the text of a talk given at the Rome Conference &#34;The Birth of the Universe and Fundemental Physics&#34;, May, 1994. We present the recent progress achieved in collaboration with A.Linde and D.Linde towards understanding the true nature of the global spatial structure of the universe as well as the most general stationary characteristics of its ti

Dmitri Zaitsev

Let $D$ be a domain in $C^n$ and $G$ a topological group which acts effectively on $D$ by holomorphic automorphisms. In this paper we are interested in projective linearizations of the action of $G$, i.e. a linear representation of $G$ in some $C^{N+1}$ and an equivariant imbedding of $D$ into $¶^N$ with respect to this representation. The domains we discuss

Jaume Amoros

Restrictions are placed on the presentation and holonomy algebra of a Kähler group. Let $X$ be compact Kähler. It is known that the formality of $X$, its Albanese map and the Hodge structure of $H^{\ast}(X)$ impose restrictions on the holonomy algebra of $π_1 X$. We derive further restrictions from Sullivan&#39;s 1-minimal model. An effective algorithm is gi

Tohsuke Urabe

This is the abstract prepared for Workshop on Topology and Geometry (Zhang jiang, China, October 1994), and is a review of my recent works. What kinds of combinations of singularities can appear in small deformation fibers of a fixed singularity? We consider this problem for hypersurface singularities on complex analytic spaces of dimension 2. For all singul

B. Schroer

Laymen and sometimes even physicists think of natural sciences, in particular of theoretical and mathematical physics often as subjects, which unfold according to an intrinsic logical pattern, with the limitations being set only by the conceptual and (in case of mathematical physics) mathematical developments of the times. This view certainly cannot be maint

Yoshio Koide

Running quark mass values $m_q(μ)$ at some typical energy scales ($μ=1$ GeV, $μ=m_W$, and so on) are reviewed. The values depend considerably on the value of $Λ_{\overline{MS}}$, especially, the value of top quark mass at $μ=1$ GeV does so. The relative ratios of light quark masses ($m_u$, $m_d$ and $m_s$) to heavy quark masses ($m_c$, $m_b$ and $m_t$) are s

R. Putz, R. Preuss, A. Muramatsu, W. Hanke

It is shown that the low-energy single-particle excitation-spectrum of the three-band Hubbard model at hole-dopings away from half-filling agrees remarkably well with Quantum Monte Carlo data and spectroscopic experiments within the framework of a conserving approximation that includes self-consistently the interaction with charge, spin, and two-particle flu

Sudhansu S. Mandal, S. Ramaswamy, V. Ravishankar

We study the finite temperature (FT) effects on integer quantum Hall effect (IQHE) and fractional quantum Hall effect (FQHE) as predicted by the composite fermion model. We find that at $T\neq 0$, universality is lost, as is quantization because of a new scale $T_0=\pi\rho /m^\ast p$. We find that this loss is not inconsistent with the experimentally observe

S. Shelly Sharma, N. K. Sharma

Boson creation operators constructed from linear combinations of q- deformed zero coupled nucleon pair operators acting on the nucleus (A,0), are used to derive pp-RPA equations. The solutions of these equations are the pairing vibrations in (A${\underline{+}}$2) nuclei. For the $0^+_1$ and $0^+_2$ states of the nucleus $^{208}$Pb, the variations of relative