December 1995 arXiv papers — page 8

T. Celik, Y. Gunduc, M. Aydin

The two-dimensional Potts Model with seven states under external field is studied using a cluster algorithm. Cluster size distribution and the fluctuations in the average cluster size provide helpful information on the order of phase transitions.

V. V. Afonin, Yu. M. Galperin

Average persistent current over a set of diffusive metallic rings with fixed number of electrons is considered. We study the the case where the phase breaking time is much greater than an inverse average inter-level distance. In such a situation, many return events for an electron have to be taken into account. As a result, one arrives at a non-perturbative

Hideaki Aoyama, Toshiyuki Harano, Masatoshi Sato, Shinya Wada

Based on the new valley equation, we propose the most plausible method for constructing instanton-like configurations in the theory where the presence of a mass scale prevents the existence of the classical solution with a finite radius. We call the resulting instanton-like configuration as valley instanton. The detail comparison between the valley instanton

H. Awata, Y. Matsuo, T. Yamamoto

Using the collective field technique, we give the description of the spin Calogero-Sutherland Model (CSM) in terms of free bosons. This approach can be applicable for arbitrary coupling constant and provides the bosonized Hamiltonian of the spin CSM. The boson Fock space can be identified with the Hilbert space of the spin CSM in the large $N$ limit. We show

Richard S. Ellis, Matthew Colless, Tom Broadhurst, Jeremy Heyl

We present a detailed determination of the restframe B-band galaxy luminosity function (LF) as a function of redshift and star formation activity from z=0 to z=0.75. The dataset used for this purpose is a combined sample of over 1700 redshifts spanning a wide range in apparent magnitude, 11.5<B<24.0, which we term the Autofib Redshift Survey. The sample incl

R. M. Kashaev

The local Yang-Baxter equation (YBE), introduced by Maillet and Nijhoff, is a proper generalization to 3 dimensions of the zero curvature relation. Recently, Korepanov has constructed an infinite set of integrable 3-dimensional lattice models, and has related them to solutions to the local YBE. The simplest Korepanov&#39;s model is related to the star-triang

Almut Beige, Gerhard C. Hegerfeldt

The projection postulate has been used to predict a slow-down of the time evolution of the state of a system under rapidly repeated measurements, and ultimately a freezing of the state. To test this so-called quantum Zeno effect an experiment was performed by Itano et al. (Phys. Rev. A 41, 2295 (1990)) in which an atomic-level measurement was realized by mea

Fan Wang, Jia-lun Ping, Guanh-han Wu, Li-jiang Teng

The quark delocalization and color screening model, a quark potential model, is used for a systematic search of dibaryon candidates in the $u,d$ and $s$ three flavor world. Color screening which appears in unquenched lattice gauge calculations and quark delocalization (which is similar to electron delocalization in molecular physics) are both included. Flavo

Bjorn Poonen

We classify the graphs that can occur as the graph of rational preperiodic points of a quadratic polynomial over $\bold Q$, assuming the conjecture that it is impossible to have rational points of period $4$ or higher. In particular, we show under this assumption that the number of preperiodic points is at most~$9$. Elliptic curves of small conductor and the

Menachem Kojman, Saharon Shelah

A ZFC Dowker space is constructed which has cardinality $\aleph_{ω+1}$. This provides a bound in ZFC to the first cardinal in which there is a ZFC Dowker space. The space we construct is a closed and cofinal subspace of M.~E.~Rudin&#39;s Dowker space from 1971. A theorem from pcf theory used in the proof, but otherwise the proof is elementary.

A. A. Tseytlin

We compare order $R^4$ terms in the 10-dimensional effective actions of SO(32) heterotic and type I superstrings from the point of view of duality between the two theories. Some of these terms do not receive higher-loop corrections being related by supersymmetry to `anomaly-cancelling&#39; terms which depend on the antisymmetric 2-tensor. At the same time, t

Cumrun Vafa

We consider type IIA compactification on $K3$. We show that the instanton subsectors of the worldvolume of $N$ 4-branes wrapped around $K3$ lead to a Hagedorn density of BPS states in accord with heterotic-type IIA duality in 6 dimensions. We also find evidence that the correct framework to understand the results of Nakajima on the appearance of affine Kac-M

C. R. Hagen

The second virial coefficient for non-Abelian Chern-Simons particles is recalculated. It is shown that the result is periodic in the flux parameter just as in the Abelian theory.

H. J. de Vega, N. sánchez

Recent progress on string theory in curved spacetimes is reviewed. The string dynamics in cosmological and black hole spacetimes is investigated.The methods to solve the string equations of motion in curved spacetimes are described.That is, the perturbation approach, the null approach, the $τ$-expansion, and the construction of global solutions.The behaviour

N. Tetradis, D. F. Litim

We study exact renormalization group equations in the framework of the effective average action. We present analytical solutions for the scale dependence of the potential in a variety of models. These solutions display a rich spectrum of physical behaviour such as fixed points governing the universal behaviour near second order phase transitions, critical ex

R. MacKenzie, P. K. Panigrahi, S. Sakhi

The phase structure of a $(2+1)$ - dimensional model of relativistic fermions with a four fermi interaction is analyzed in the strong coupling regime using the large $N$ perturbation theory. It is shown that, this model exhibits a low temperature superconducting phase due to the vortex-anti vortex binding via Kosterlitz-Thouless mechanism. Above a critical t

N Linden A J Macfarlane, J W van Holten

A complete, straightforward and natural Lagrangian description is given for the classical non-relativistic dynamics of a particle with colour or internal symmetry degrees of freedom moving in a background Yang-Mills field. This provides a new simple Lagrangian formalism for Wong&#39;s equations for spinless particles, and presents also their generalisation,

Luca Lusanna

The intrinsic covariant 1-time description (rest-frame instant form) for N relativistic scalar particles is defined. The system of N charged scalar particles plus the electromagnetic field is described in this way: the study of its Dirac observables allows the extraction of the Coulomb potential from field theory and the regularization of the classical self-

Emilio N. M. Cirillo, Giuseppe Gonnella, Alessandro Pelizzola

A vertex model introduced by M. Bowick, P. Di Francesco, O. Golinelli, and E. Guitter (cond-mat/9502063) describing the folding of the triangular lattice onto the face centered cubic lattice has been studied in the hexagon approximation of the cluster variation method. The model describes the behaviour of a polymerized membrane in a discrete three--dimension

J. W. van Holten

The world-line path-integral representation of fermion propagators is discussed. Particular attention is paid to the representation of $γ_5$, which is connected to the realization of manifest world-line supersymmetry.

G. Sartori, V. Talamini

All four dimensional orbit spaces of compact coregular linear groups have been determined. The results are obtained through the integration of a universal differential equation, that only requires as input the number of elements of an integrity basis of the ideal of polynomial invariants of the linear group. Our results are relevant and lead to universality

P. S. Howe

An overview is given of the application of twistor geometric ideas to supersymmetry with particular emphasis on the construction of superspaces associated with four-dimensional spacetime. Talk given at Leuven conference, July 1995.

J. L. F. Barbon, S. Ramgoolam

We study embeddings of the Prasad-Sommerfield monopole solution in SU(N) Super-QCD (N>2), where the role of the Higgs field is played by the squarks in the fundamental representation. Classically, the resulting configurations live in a phase with unbroken SU(k) subgroups of SU(N) (as a result they are not topologically stable). The structure of zero modes is

Edmond L. Berger, Xiaofeng Guo, Jianwei Qiu

Using $e^+e^-\rightarrowγ+ X$ as an example, we show that the conventional factorization theorem in perturbative quantum chromodynamics breaks down for isolated photon cross sections in a well defined part of phase space. Implications and physical consequences are discussed.

Zhi-zhong Xing

The two-body mesonic $B$ decays induced only via a single $W$-exchange or annihilation quark diagram, such as $B^-_u\rightarrow D^{(*)-}_sK^{(*)0}$ and $\bar{B}^0_d\rightarrow D^{(*)+}_sK^{(*)-}$, are analyzed in the factorization approximation. We estimate the branching ratios for those transitions into two pseudoscalar mesons, and find them to be negligibl

Csaba Csaki, Lisa Randall

There are few robust solutions to the doublet-triplet splitting problem in supersymmetric GUT theories. One of the more promising solutions is the Higgs as pseudo-Goldstone boson mechanism. In its minimal implementation, such a solution places an additional restriction on the parameter space of the minimal supersymmetric standard model. A testable consequenc

Gautam Bhattacharyya, Amitava Raychaudhuri

If $R$-parity is broken and the photino, although unstable, does not decay within the detector, then in new semileptonic $B$-decay modes a light ($\sim$ 2--3 GeV) photino can be produced carrying missing energy. However, the photino, being massive, arranges a different kinematical configuration for the visible decay products as compared to a standard semilep

Bodo Lampe

The top quark has been discovered at FERMILAB last year. The following features of top quark physics will be discussed in this article: the top quark in the standard model production and decay of the top quark in proton collisions (direct evidence for top) virtual effects of top quarks in electroweak observables (indirect evidence for top)

Kirsten Büttner

Using the Schwinger-Dyson equations the possible infrared behaviour of the gluon propagator is studied. Previous work performed in axial gauges is reviewed, the approximations needed detailed and the difficulties of their justification discussed. We then turn to the Landau gauge and investigate the possibility of a gluon propagator less singular than $1/p^{2

J. Blümlein

The theoretical status of perturbative QED and QCD corrections to deep inelastic scattering is reviewed.

B. Ananthanarayan, P. Minkowski

We consider the reaction $e^- e^- \rightarrow W^- W^-$ mediated by possible heavy neutrino exchange at future LINAC energies of $\sqrt{s}>> 2 m_W$. This reaction is sensitive to CP phases of the neutrino mixing matrices, even at the level of Born amplitudes. Certain integrated cross-sections are shown to have the power to resolve the CP phases when the exper

A. V. Kotikov

We extend Gegenbauer Polynomials technique to evaluate a class of complicated Feynman diagrams. New results in the form of $_3F_2$-hypergeometrical series of unit argument, are presented. As a by-product, we present a new transformation rule for $_3F_2$-hypergeometric series with argument $-1$.

Jan Fischer

After reviewing basic facts about large-order behaviour of perturbation expansions in various fields of physics, I consider several alternatives to the Borel summation method and discuss their relevance to different physical situations. Then I convey news about the singularities in the Borel plane, and discuss the topical subject of the resummation of renorm

S. Urano, D. Ring, R. Arnowitt

It is shown that non-renormalizable gravitational interactions in the Higgs sector of supersymmetric grand unified theories (GUT&#39;s) can produce the breaking of the unifying gauge group $G$ at the GUT scale $M_{\rm GUT} \sim 10^{16}$~GeV. Such a breaking offers an attractive alternative to the traditional method where the superheavy GUT scale mass paramet

Hai-Yang Cheng

Contrary to what has been often claimed in the literature, we clarify that the hard photon-gluon cross section $\gg_{\rm hard}(x)$ in polarized deep inelastic scattering calculated in the gauge-invariant factorization scheme does {\it not} involve any soft contributions and hence it is genuinely {\it hard}. We show that the polarized proton structure functio

John F. Donoghue

This is a pedagogical introduction to the treatment of general relativity as a quantum effective field theory. Gravity fits nicely into the effective field theory description and forms a good quantum theory at ordinary energies.

Gérard Clément

The construction of self-dual vortex solutions to the Chern-Simons-Higgs model (with a suitable eighth-order potential) coupled to Einstein gravity in (2 + 1) dimensions is reconsidered. We show that the self-duality condition may be derived from the sole assumption $g_{00} = 1$. Next, we derive a family of exact, doubly self-dual vortex solutions, which int

Pavel Exner

We consider a Schrödinger particle on a graph consisting of $\,N\,$ links joined at a single point. Each link supports a real locally integrable potential $\,V_j\,$; the self--adjointness is ensured by the $\,δ\,$ type boundary condition at the vertex. If all the links are semiinfinite and ideally coupled, the potential decays as $\,x^{-1-ε}$ along each of t

S. Finashin

Quotients $Y=X/conj$ by the complex conjugation $conj\: X\to X$ for complex surfaces $X$ defined over $\R$ tend to be completely decomposable when they are simply connected, i.e., split into connected sums $\#_n CP^2\#_m\barCP^2$ if $w_2(Y)\ne0$, or into $\#_n(S^2\times S^2)$ if $w_2(Y)=0$. The author proves this property for complete intersections which are

Fernando Moraes

One method of gaining some insight into the motion of particles in a medium with topological defects (e.g., electrons in a dislocated metal) is to look at the geodesics of the medium around the defect. In this work the Hamilton-Jacobi equation for the geodesics in a continuous medium containing a torsional defect, an edge dislocation, is solved by using pert

Tom Chou, Eric G. Blackman

This study is motivated by the extraordinary process of single bubble sonoluminescence (SBSL), where an acoustically driven spherical shock is thought to power the emitted radiation. We propose new experiments using an external magnetic field which can induce anisotropies in both the shock propagation and radiation pattern. The effects will depend on the tem

J. J. Deisz, D. W. Hess, J. W. Serene

We present single-particle and thermodynamic properties of the half-filled single-band Hubbard model in 2D calculated in the self-consistent fluctuation exchange approximation. The low-energy excitations at moderate temperatures and small $U$ are quasiparticles with a short lifetime. As the temperature is lowered, coupling to evolving spin fluctuations leads

D. W. Hess, J. J. Deisz, J. W. Serene

We present fully self-consistent calculations in the fluctuation exchange approximation for the half-filled Hubbard model in 2D. A non-fermi liquid state evolves with decreasing temperature in this self-consistent model of coupled spin fluctuations and quasiparticles. The mean field phase transition to long-range antiferromagnetic order is suppressed and we

K. A. Matveev, L. I. Glazman, H. U. Baranger

We study the Coulomb blockade of tunneling through a double quantum dot. The temperature dependence of the linear conductance is strongly affected by the inter-dot tunneling. As the tunneling grows, a crossover from temperature-independent peak conductance to a power-law suppression of conductance at low temperatures is predicted. This suppression is a manif

Ch. Gruber, D. F. Wang

This talk reviews some recent progresses in the studies of low dimensional electronic models of strong correlations.

Michael W. Deem, David R. Nelson

We examine the shapes and energies of 5- and 7-fold disclinations in low-temperature hexatic membranes. These defects buckle at different values of the ratio of the bending rigidity, $κ$, to the hexatic stiffness constant, $K_A$, suggesting {\em two} distinct Kosterlitz-Thouless defect proliferation temperatures. Seven-fold disclinations are studied in detai

Takashi Yamamoto, Norio Kawakami, Sung-Kil Yang

Applying boundary conformal field theory we study the low-energy critical behavior of the Calogero-Sutherland model of $BC_N$-type. The universality class of the model is found to be a {\it chiral} Tomonaga-Luttinger liquid. Various correlation exponents depending on the interaction strength are obtained.

M. Sassetti, H. Schomerus, U. Weiss

As a generic model for transport of interacting fermions through a barrier or interstitials in a lattice, quantum Brownian motion in a periodic potential is studied. There is a duality transformation between the continuous coordinate or phase representation and the discrete momentum or charge representation for general frequency-dependent damping. Sub-Ohmic

S. Fujimoto, N. Kawakami

Exact critical properties of the one-dimensional SU($N$) interacting fermion model with open boundaries are studied by using the Bethe ansatz method. We derive the surface critical exponents of various correlation functions using boundary conformal field theory. They are classified into two types, i.e. the exponents for the chiral SU($N$) Tomonaga-Luttinger

Malte Henkel

The phase diagram of the two-dimensional extended q-states Potts model is investigated in the q->1 limit. This is equivalent to studying the phase diagram of a two-dimensional infinite interacting lattice animal. An exact solution on the Bethe lattice and a Migdal-Kadanoff renormalization group calculation predict a line of theta transitions from an extended

Malte Henkel

Domain walls in the spin S quantum Ising chain at zero temperature are considered. Quantum effects prevent the walls from being sharp and delocalize the exact eigenstates. The absence of a characteristic length of the domain walls is reflected in the finite-size scaling of the spectrum of the Hamiltonian.

Frank Göhmann, Vladimir Inozemtsev

We present two pairs of Y($sl_2$) Yangian symmetries for the trigonometric and hyperbolic versions of the Hubbard model with non-nearest-neighbour hopping. In both cases the Yangians are mutually commuting, hence can be combined into a Y($sl_2$)$\oplus$Y($sl_2$) Yangian. Their mutual commutativity is of dynamical origin. The known Yangians of the Haldane-Sha

Chee Kwan Gan, Jian-Sheng Wang

We propose a computational method to obtain series expansions in powers of time for general dynamical systems described by a set of hierarchical rate equations. The method is generally applicable to problems in both equilibrium and nonequilibrium statistical mechanics such as random sequential adsorption, diffusion-reaction dynamics, and Ising dynamics. New

Uri Alon, Martin Evans, Haye Hinrichsen, David Mukamel

A class of nonequilibrium models with short-range interactions and sequential updates is presented. The models describe one dimensional growth processes which display a roughening transition between a smooth and a rough phase. This transition is accompanied by spontaneous symmetry breaking, which is described by an order parameter whose dynamics is non-conse

Antonio de Padua, J. A. de Miranda-Neto, Isaac M. Xavier, Fernando Moraes

In this work, we propose a geometrical model for the study of conformational properties of a starburst dendrimer with the topology of a truncated Bethe lattice. A convenient embedding of the Bethe lattice in the hyperbolic plane is used to study the architecture of the dendrimer. As results, we find an upper bound for the molecular size and the density profi

Gerhard C. Hegerfeldt, Dirk G. Sondermann

For the time development of a single system in the quantum jump approach or for quantum trajectories one requires the conditional (reduced) Hamiltonian between jumps and the reset operator after a jump. Explicit expressions for them are derived for a general N-level system by employing the same assumptions as in the usual derivation of the Bloch equations. W

HongSheng Zhao, Francisco Prada

A five-parameter fitting formula for the line-of-sight stellar velocity distributions of steady state systems is proposed. It can faithfully reproduce velocity distributions of theoretical models ranging from nearly Gaussian profiles to strongly skewed or mildly double-peaked profiles. In contrast to van der Marel and Franx (1993) and Kuijken and Merrifield

HongSheng Zhao, R. M. Rich, D. N. Spergel

We compute a microlensing map for the Galactic bar. The predicted event rate and event duration distribution are consistent with the $55$ events recently reported by the MACHO and OGLE collaborations. Most of the events are due to lensing by stars in the near end of the bar. Lens mass functions with about 30-60\% of lens mass as brown dwarfs are rejected at

HongSheng Zhao

A 3D steady state stellar dynamical model for the Galactic bar is constructed with 485 orbit building blocks using an extension of Schwarzschild technique. The weights of the orbits are assigned using non-negative least square method. The model fits the density profile of the COBE light distribution, the observed solid body stellar rotation curve, the fall-o

Ricardo A. Flores, Joel R. Primack

Many multiply--imaged quasars have been found over the years, but none so far with image separation in excess of $8\arcsec$. The absence of such large splittings has been used as a test of cosmological models: the standard Cold Dark Matter model has been excluded on the basis that it predicts far too many large--separation double images. These studies assume

Ken Ebisawa, Lev G. Titarchuk, Sandip K. Chakrabarti

Most black hole candidates exhibit characteristic power-law like hard X-ray emission above $\sim$ 10 keV. In the {\em high state}, in which 2 -- 10 keV luminosity is relatively high, the energy index of the hard X-ray emission is usually greater than 1 --- typically $\sim 1.5$. On the other hand, in the {\em low state}, the hard X-ray energy index is 0.3 --

F. K. Liu

Polytropic models play a very important role in galactic dynamics and in the theory of stellar structure and evolution. However, in general, the solution of the Lane-Emden equation can not be given analytically but only numerically. In the Lane-Emden equation can not be given analytically but only numerically. In this paper we give a very good and simple ana

Robert Braun

The scientific motivation is reviewed for a next generation radio observatory operating at frequencies between about 200 MHz and 2 GHz with about 2 orders of magnitude greater sensitivity than that which is currently available, together with sub-arcsecond angular resolution. Instrumental concepts for the telescope are discussed, highlighting the role of mass

K. M. Leighly, M. Dietrich, E. Waltman, R. Edelson

During 1995, the broad-line radio galaxy 3C 390.3 is the subject of a multi-wavelength monitoring campaign comprised of ROSAT HRI, IUE, and ground based optical, infrared and radio observations. We report preliminary results from the monitoring campaign focusing on the X-ray observations. Snapshot ROSAT observations being made every three days show large amp

A. I. Zabludoff, D. Zaritsky, H. Lin, D. Tucker

The violent star formation history of ``E+A&#39;&#39; galaxies and their detection almost exclusively in distant clusters is frequently used to link them to the ``Butcher-Oemler effect&#39;&#39; and to argue that cluster environment influences galaxy evolution. From 11113 spectra in the Las Campanas Redshift Survey, we have obtained a unique sample of 21 nea

A. Comastri, M. Cappi, M. Matsuoka

We present the results of an ASCA observation of the high redshift flat spectrum radio quasar S5 0836+710. The $\sim 0.4-10$ keV X-ray spectrum is remarkably flat with $Γ\sim 1.4$ and substantial intrinsic absorption at low energy. The spectral slope was found to be in good agreement with the non--simultaneous ROSAT PSPC observations while no evidence of int

Peter Schenzel

Several spectral sequence techniques are used in order to derive information about the structure of finite free resolutions of graded modules. These results cover estimates of the minimal number of generators of defining ideals of projective varieties. There are also investigations about the shifts and the dimension of Betti numbers.

P. K. Townsend

The 2-brane and 4-brane solutions of ten dimensional IIA supergravity have a dual interpretation as Dirichlet-branes, or `D-branes&#39;, of type IIA superstring theory and as `M-branes&#39; of an $S^1$-compactified eleven dimensional supermembrane theory, or M-theory. This eleven-dimensional connection is used to determine the ten-dimensional Lorentz covaria

V. Jeudy, D. Limagne, G. Waysand, J. I. Collar

Geometrical metastability, observed in superconducting type I tin flat strips, has been previously proposed as a principle for particle detection. The energy deposition of an incoming beta-particle induces the rupture of the metastability and consequently the penetration of multiquantum flux tubes into a superconducting tin strip. We present here the first a

R. R. Khuri, R. C. Myers

We derive double dimensional reduction/oxidation in a framework where it is applicable to describe general non-static (and anisotropic) $p$-brane solutions. Given this procedure, we are able to relate the dynamical interaction potential for parallel extremal $p$-branes in $D$ dimensions to that for extremal black holes in $D-p$ dimensions. In particular, we

H. B. Gao

We construct more dual pairs of type II-heterotic strings in four dimensions with $N=2,1$ spacetime supersymmetry. On the type II side the construction utilizes the various possible choices of K3 automorphisms with fixed points which transform the holomorphic two-form nontrivially, and rotation plus translation on $T^2$. The Calabi-Yau orbifolds so obtained

Andrew Strominger

It is shown that many of the $p$-branes of type II string theory and $d=11$ supergravity can have boundaries on other $p$-branes. The rules for when this can and cannot occur are derived from charge conservation. For example it is found that membranes in $d=11$ supergravity and IIA string theory can have boundaries on fivebranes. The boundary dynamics are go

Alick L. Macpherson

Evaluation of nucleon decay modes and branching ratios in a non-minimal supersymmetric SO(10) grand unified theory is presented. The non-minimal GUT considered is the supersymmetrised version of the `realistic&#39; SO(10) model originally proposed by Harvey, Reiss, and Ramond, which is realistic in that it gives acceptable charged fermion and neutrino masses

Laurence G. Yaffe

A talk presented at &#34;String Gravity and Physics at the Planck Energy Scale&#34;, Erice, September 1995, summarizing the current understanding of the electroweak phase transition.

Gregory Mahlon, Stephen Parke

We show how to observe sizable angular correlations between the decay products of the top quark and those of the anti-top quark in top quark pair production and decay at hadron colliders. These correlations result from the large asymmetry in the rate for producing like-spin versus unlike-spin top quark pairs provided the appropriate spin axes are used. The e

Somendra M. Bhattacharjee, Sutapa Mukherji

We discuss various aspects of the randomly interacting directed polymers with emphasis on the phases and phase transition. We also discuss the behaviour of overlaps of directed paths in a random medium.

B. A. Sanborn

The nonequilibrium total dielectric function lends itself to a simple and general method for calculating the inelastic collision term in the electron Boltzmann equation for scattering from a coupled mode system. Useful applications include scattering from plasmon-polar phonon hybrid modes in modulation doped semiconductor structures. This paper presents nume

Enzo Branchini, Manolis Plionis, Dennis W. Sciama

Using a dynamical 3-D reconstruction procedure we estimate the peculiar velocities of $R\ge0$ Abell/ACO galaxy clusters from their measured redshift within 25000 km/sec. The reconstruction algorithm relies on the linear gravitational instability hypothesis, assumes linear biasing and requires an input value of the cluster $β$-parameter ($β_c \equiv Ω_{\circ}

J. I. Collar

Cosmological models with cosmic string and texture seeded universes predict a present abundance of very dense clumps of Cold Dark Matter particles. Their crossing through the solar system would induce a non-negligible amount of radiation damage to all living tissue; the severity of such an episode is assessed. The estimated frequency of these crossings agree

M. Yu. Kalmykov

We discuss the role of additional local symmetries related to the transformations of connection fields in the affine-metric theory of gravity. The corresponding BRST transformations connected with all symmetries (general coordinate, local Lorentz and extra) are constructed. It is shown, that extra symmetries give the additional contribution to effective acti

Carlos R. Cassanello, Eduardo Fradkin

We consider a band of fermions in two space dimensions with a flux phase (relativistic) dispersion relation coupled to a local magnetic impurity via an $ s-d$ interaction. This model describes spinons of a flux phase and it is also a qualitative model of the quasiparticles in a $d_{x^2-y^2}$ superconductor. We find a zero-temperature phase transition at a fi

John H. Schwarz

The conditions for the cancellation of all gauge, gravitational, and mixed anomalies of $N=1$ supersymmetric models in six dimensions are reviewed and illustrated by a number of examples. Of particular interest are models that cannot be realized perturbatively in string theory. An example of this type, which we verify satisfies the anomaly cancellation condi

M. Ichioka, N. Hayashi, N. Enomoto, K. Machida

Vortex structure of pure $d_{x^2-y^2}$-wave superconductors is microscopically analyzed in the framework of the quasi-classical Eilenberger equations. Selfconsistent solution for the $d$-wave pair potential is obtained for the first time in the case of an isolated vortex. The vortex core structure, i.e., the pair potential, the supercurrent and the magnetic

V. P. Maslov, O. Yu. Shvedov

We develop a new method of constructing a large N asymptotic series in powers of $N^{-1/2}$ for the function of N arguments which is a solution to the Cauchy problem for the equation of a special type. Many-particle Wigner, Schrödinger and Liouville equations for a system of a large number of particles are of this type, when the external potential is of orde

V. P. Karassiov

We examine applications of polynomial Lie algebras $sl_{pd}(2)$ to solve physical tasks in $G_{inv}$-invariant models of coupled subsystems in quantum physics. A general operator formalism is given to solve spectral problems using expansions of generalized coherent states, eigenfunctions and other physically important quantities by power series in the $sl_{p

M. A. Nielsen

We investigate measures of chaos in the measurement record of a quantum system which is being observed. Such measures are attractive because they can be directly connected to experiment. Two measures of chaos in the measurement record are defined and investigated numerically for the case of a quantum kicked top. A smooth transition between chaotic and regula

V. P. Maslov, O. Yu. Shvedov

We investigate an infinite dimensional analog of the theory of Lagrangian manifolds with complex germs. To such a manifold we assign a canonical operator that depends on creation and annihilation operators. This operator is by definition the geometrical quantization for these isotropic manifolds with complex germs. We prove that for secondary quantized equat

M. Reuter

Starting from the concept of the universal exterior algebra in non-commutative differential geometry we construct differential forms on the quantum phase-space of an arbitrary system. They bear the same natural relationship to quantum dynamics which ordinary tensor fields have with respect to classical hamiltonian dynamics.

M. Abud, J. -P. Ader, L. Cappiello

The BRST anomaly which may be present in the induced $W_n$ gravity quantized on the light-cone is evaluated in the geometrical framework of Zucchini. The cocycles linked by the cohomology of the BRST operator to the anomaly are straightforwardly calculated thanks to the analogy between this formulation and the Yang-Mills theory. We give also a conformally co

Deog Ki Hong, Jin Young Kim

We calculate the anomalous magnetic moment of anyons in three dimensional $CP^{N-1}$ model with a Chern-Simons term in various limits in $1/N$ expansion. We have found that for anyons of infinite mass the gyromagnetic ratio ($g$-factor) is 2 up to the next-to-leading order in $1/N$. Our result supports a recent claim that the $g$-factor of nonrelativistic an

Sangyong Jeon, Laurence G. Yaffe

The evaluation of hydrodynamic transport coefficients in relativistic field theory, and the emergence of an effective kinetic theory description, is examined. Even in a weakly-coupled scalar field theory, interesting subtleties arise at high temperatures where thermal renormalization effects are important. In this domain, a kinetic theory description in term

Hiroyuki Hagura, Noritsugu Tsuda, Tetsuyuki Yukawa

We study phases and fractal structures of three-dimensional simplicial quantum gravity by the Monte-Carlo method. After measuring the surface area distribution (SAD) which is the three-dimensional analog of the loop length distribution (LLD) in two-dimensional quantum gravity, we classify the fractal structures into three types: (i) in the hot (strong coupli

Seth Major, Lee Smolin

We describe a deformation of the observable algebra of quantum gravity in which the loop algebra is extended to framed loops. This allows an alternative nonperturbative quantization which is suitable for describing a phase of quantum gravity characterized by states which are normalizable in the measure of Chern-Simons theory. The deformation parameter, q, de

M. N. Tentyukov

We investigate the vacuum and charged spherically symmetric static solutions of the Einstein equations on cosmological background. The background metric is not flat, but curved, with constant - curvature spatial sections. Both vacuum and charged cases contain two branches. The first branches transform into the Schwarzschild and Reissner-Nordström solutions i

Erik Sorensen, Eric Roddick

The superconductor to insulator transition in the presence of long-range Coulomb interactions is studied using Monte Carlo techniques. At integer filling the transition is second order. At half filling we find evidence of a first order transition to a state with non-zero $S_{π,π}$. No intervening supersolid phase is observed. Off half-filling two separate tr

Masanori Yamanaka, Shinsuke Honjo, Yasuhiro Hatsugai, Mahito Kohmoto

We investigate the one-dimensional strongly correlated electron models which have the resonating-valence-bond state as the exact ground state. The correlation functions are evaluated exactly using the transfer matrix method for the geometric representations of the valence-bond states. In this method, we only treat matrices with small dimensions. This enables

George A. Kiraz

This paper demonstrates how the challenging problem of the Arabic broken plural and diminutive can be handled under a multi-tape two-level model, an extension to two-level morphology.

Ramesh Narayan

General properties of advection-dominated accretion flows are discussed. Special emphasis is given to the optically thin branch of solutions, which has very high ion and electron temperatures and is thermally stable. This solution branch has been applied to a number of low-luminosity accreting black holes. The models have resolved some puzzles and have provi

G. Xiao

We classify K3 surfaces with a non-symplectic finite automorphism of high order. It is shown that such an automorphism cannot be of order 60, and for each of the orders 38, 44, 48, 50, 54 and 66, there exists a unique K3 surface with such an automorphism.

Rajiv V. Gavai, Manu Mathur

We examine certain issues related to the universality of the SU(2) lattice gauge theory at non-zero temperatures. Using Monte Carlo simulations and strong coupling expansions, we study the behavior of the deconfinement transition in an extended coupling plane (beta, beta_A) around the tricritical point where the deconfinement transition changes from second t