September 1992 arXiv papers — page 4

E. Hernandez-Garcia, T. Ala-Nissila, Martin Grant

We present a theoretical and numerical investigation of the effect of a time-varying external driving force on interface growth. First, we derive a relation between the roughening exponents which comes from a generalized Galilean invariance, showing how the critical dimension of the model is tunable with the external field. We further conjecture results for

Varun Sahni

Invited talk delivered at the International Conference on General Relativity and Cosmology (ICGC), Ahmedabad, India; 13 - 18 December 1991. To appear in its proceedings.

Menachem Kojman, Saharon Shelah

Our theme is that not every interesting question in set theory is independent of $ZFC$. We give an example of a first order theory $T$ with countable $D(T)$ which cannot have a universal model at $\aleph_1$ without CH; we prove in $ZFC$ a covering theorem from the hypothesis of the existence of a universal model for some theory; and we prove --- again in ZFC

David London, C. P. Burgess

Analyses which use loop calculations to put constraints on anomalous trilinear gauge boson couplings (TGC's) often give bounds which are much too stringent. The reason has nothing to do with gauge invariance, in contrast to the recent claims of de Rujula et. al., since the lagrangians used in these calculations ARE gauge invariant, with the SU(2)L X U(1)

John Preskill, Alexander Vilenkin

We systematically analyze the decay of metastable topological defects that arise from the spontaneous breakdown of gauge or global symmetries. Quantum-mechanical tunneling rates are estimated for a variety of decay processes. The decay rate for a global string, vortex, domain wall, or kink is typically suppressed compared to the decay rate for its gauged cou

E. J. Chun, A. Lukas

We examine discrete gauge symmetries in axionic extensions of the SSM which provide a solution of the $μ$-problem. Automatic-PQ symmetry and proton stability are shown to be guaranteed by certain discrete symmetries. Focusing on the L-violating discrete symmetries we discuss two sources of neutrino masses and their relevance for the solar neutrino problem.

The UKQCD Collaboration, S. P. Booth, D. S. Henty, A. Hulsebos

{}From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of $R$-values and hence estimate the scale $Λ_{\msbar} $. Detailed results are presented for $SU(3)$ pure gauge theory.

The UKQCD Collaboration, S. P. Booth, A. Hulsebos, A. C. Irving

We measure accurate values of the inter-quark potentials on a $48^{3}56$ lattice with SU(2) pure gauge theory at $ β=2.85$. The scale is set by extracting the string tension - we obtain ${\sqrt K}a=0.063(3)$ at $β=2.85.$ From a careful study of the small-$R$ potentials in the region 2 GeV $< R^{-1} < 5$ GeV, we extract a running coupling constant and estimat

U. -J. Wiese

In Binder&#39;s approach the reduced interface tension sigma of the Ising model in the broken phase is determined from the finite volume effects of the partition function Z(M) at fixed total magnetization M. For small |M| the partition function of a system of size L^d with periodic boundary conditions is dominated by configurations with two interfaces, such

Fabian H. L. Essler, Vladimir E. Korepin, Kareljan Schoutens

We present a new model describing strongly correlated electrons on a general $d$-dimensional lattice. It differs from the Hubbard model by interactions of nearest neighbours, and it contains the $t$-$J$ model as a special case. The model naturally describes local electron pairs, which can move coherently at arbitrary momentum. By using an $η$-pairing mechani

G. Barnich, R. Constantinescu, P. Gregoire

The general BRST-anti-BRST construction in the framework of the antifield-antibracket formalism is illustrated in the case of the Freedmann-Townsend model.

G. Aldazabal, M. Bonini, J. M. Maldacena

We study the discrete state structure of $\hat c=1$ superconformal matter coupled to 2-D supergravity. Factorization properties of scattering amplitudes are used to identify these states and to construct the corresponding vertex operators. For both Neveu-Schwarz and Ramond sectors these states are shown to be organized in SU(2) multiplets. The algebra genera

A. Abada, A. H. bougourzi, M. A. El Gradechi

We present the extension of the Wakimoto construction to the $su(2)_k$ quantum current algebra and its associated $Z_k$ quantum parafermion algebra. This construction is achieved in terms of various deformations of three classical free boson fields. We also give the vertex operators corresponding to the quantum spin-$j$ representation.

David A. Lowe

Black hole evaporation may lead to massive or massless remnants, or naked singularities. This paper investigates this process in the context of two quite different two dimensional black hole models. The first is the original CGHS model, the second is another two dimensional dilaton-gravity model, but with properties much closer to physics in the real, four d

Thomas G. Rizzo

We examine the production of a new $Z&#39;$ gauge boson in association with photons or jets at future hadron supercolliders as a probe of its couplings to fermions. Associated jet production is found to be rather insensitive to these couplings and suffers from large uncertainties as well as substantial backgrounds. On the other hand, the ratio of rates for a

Eugeni Akhmedov, Zurab Berezhiani, Goran Senjanovic, Zhijian Tao

Zee-type models with Majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, we find a particularly simple solution to the solar neutrino problem, which besides $ν_{17}$ predicts a light Zeldovich-Konopinski-Mahmoud neutrino $ν_{light}=ν_e+ν_

A Donnachie, P V Landshoff

Regge theory provides a very simple and economical description of all total cross sections

Ulli Wolff

An overview is given over the recently developed and now widely used Monte Carlo algorithms with reduced or eliminated critical slowing down. The basic techniques are overrelaxation, cluster algorithms and multigrid methods. With these tools one is able to probe much closer than before the universal continuum behavior of field theories on the lattice.

J. W. Moffat

The local Lorentz and diffeomorphism symmetries of Einstein&#39;s gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early Universe, at a critical temperature $T_c$ below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time and the wave function of the U

Wei Chen, Gordon W. Semenoff, Yong-Shi Wu

Perturbative renormalization of a non-Abelian Chern-Simons gauge theory is examined. It is demonstrated by explicit calculation that, in the pure Chern-Simons theory, the beta-function for the coefficient of the Chern-Simons term vanishes to three loop order. Both dimensional regularization and regularization by introducing a conventional Yang-Mills componen

Satoshi Iso, Dimitra Karabali, B. Sakita

We present field theoretical descriptions of massless (2+1) dimensional nonrelativistic fermions in an external magnetic field, in terms of a fermionic and bosonic second quantized language. An infinite dimensional algebra, $W_{\infty}$, appears as the algebra of unitary transformations which preserve the lowest Landau level condition and the particle number

J. M. Figueroa-O&#39;Farrill, E. Ramos, S. Stanciu

We give a simple geometrical interpretation of classical $\W$-transformations as deformations of constant energy surfaces by canonical transformations on a two-dimensional phase space.

Norisuke Sakai

The continuum (Liouville) approach to the two-dimensional (2-D) quantum gravity is reviewed with particular attention to the $c=1$ conformal matter coupling, and new results on a related problem of dilaton gravity are reported. After finding the physical states, we examine the procedure to compute correlation functions. The physical states in the relative co

Philip Boyland

This paper investigates the existence of Denjoy minimal sets and, more generally, strictly ergodic sets in the dynamics of iterated homeomorphisms. It is shown that for the full two-shift, the collection of such invariant sets with the weak topology contains topological balls of all finite dimensions. One implication is an analogous result that holds for dif

Dimitri Alekseevsky, Peter W. Michor

Let $G\subset GL(V)$ be a linear Lie group with Lie algebra $\frak g$ and let $A(\frak g)^G$ be the subalgebra of $G$-invariant elements of the associative supercommutative algebra $A(\frak g)= S(\frak g^*)\otimes \La(V^*)$. To any $G$-structure $π:P\to M$ with a connection $ω$ we associate a homomorphism $μ_ω:A(\frak g)^G\to Ω(M)$. The differential forms $μ

H. Aratyn, E. Nissimov, S. Pacheva, I. Vaysburd

The Adler-Kostant-Symes $R$-bracket scheme is applied to the algebra of pseudo-differential operators to relate the three integrable hierarchies: KP and its two modifications, known as nonstandard integrable models. All three hierarchies are shown to be equivalent and connection is established in the form of a symplectic gauge transformation. This constructi

G. Haak

We present a notion of symmetry for 1+1-dimensional integrable systems which is consistent with their group theoretic description and reproduces in special cases the known Baecklund transformation for the generalized Korteweg-deVries hierarchies. We also apply it to the relativistic invariance of the Leznov-Saveliev systems.

Changhyun Ahn

We generalize the Goddard-Kent-Olive (GKO) coset construction to the dimension 5/2 operator for $ \hat{so} (5) $ and compute the fourth order Casimir invariant in the coset model $\hat{SO} (5)_{1} \times \hat{SO} (5)_{m} / \hat{SO} (5)_{1+m} $ with the generic unitary minimal $ c < 5/2 $ series that can be viewed as perturbations of the $ m \rightarrow \inft

Y. Matsumura, N. Sakai, Y. Tanii, T. Uchino

The Liouville approach is applied to the quantum treatment of the dilaton gravity in two dimensions. The physical states are obtained from the BRST cohomology and correlation functions are computed up to three-point functions. For the $N=0$ case (i.e., without matter), the cosmological term operator is found to have the discrete momentum that plays a special

Malcolm N. Butler, Martin J. Savage

We compute the polarisability of the nucleon to leading order in chiral perturbation theory. The contributions from kaons and baryon resonances as intermediate states are included in addition to the contribution from pions and nucleons that had been previously computed. The isoscalar operators are dominated by the infrared behaviour of pion loops giving rise

Lowell S. Brown

The solution of the classical field equation generates the sum of all tree graphs. We show that the classical equation reduces to an easily solved ordinary differential equation for certain multiparticle threshold amplitudes and compute these amplitudes.

Y. N. Srivstava, A. Widom, M. H. Friedman, O. Panella

The potential energy of a static charge distribution on a lattice is rigorously computed in the standard compact quantum electrodynamic model. The method used follows closely that of Weyl for ordinary quantum electrodynamics in continuous space-time. The potential energy of the static charge distribution is independent of temperature and can be calculated fr

Heinz König

We present the results of the influence of the minimal supersymmetric standard model extended by an additional Higgs singlet N, with vacuum expectation value $v_N$, on the anomalous magnetic moment of the muon. This gives different mass matrices for the charginos and neutralinos, which are taken into account within the relevant penguin diagrams leading to a

Karl Jansen

The finite temperature phase diagram of a U(1) Higgs-Yukawa model at a finite value of the scalar self coupling $λ$ is investigated by means of a large-$N_f$ calculation and numerical simulations. The phase diagram is similar to the one at zero temperature and shows a ferromagnetic, two symmetric and an antiferromagnetic phase. However, the phase transition

Maarten Golterman, Karl Jansen, David Kaplan

We compute the Chern-Simons current induced by Wilson fermions on a $d=2n+1$ dimensional lattice, making use of a topological interpretation of the momentum space fermion propagator as a map from the torus to the sphere, $T^{d}\to S^{d}$. These mappings are shown to fall in different homotopy classes depending on the value of $m/r$, where $m$ is the fermion

Karl Jansen, Martin Schmaltz

We determine the critical momenta for chiral fermions in the domain wall model recently suggested by Kaplan. For a wide range of domain wall masses $m$ and Wilson couplings $r$ we explicitly exhibit the regions in momentum space where the fermions are chiral. We compare the critical momenta for the infinitely large system with those obtained on a finite latt

Bernd A. Berg, Balasubramanian Krishnan, Mohammad Katoot

Pure SU(2) gauge theory is the simplest asymptotically free theory in four dimensions. To investigate Euclidean quantum gravity effects in a fundamental length scenario, we simulate 4$d$ SU(2) lattice gauge theory on a dynamically coupled Regge skeleton. The fluctuations of the skeleton are governed by the standard Regge-Einstein action. From a small $2\cdot