July 1993 arXiv papers — page 7

Per Elmfors, Kari Enqvist, Iiro Vilja

The thermalization rate for long wavelength fluctuations in the Higgs field is calculated from the imaginary part of the finite temperature effective action in the unbroken phase of the Standard Model. We use improved propagators including a resummation of hard thermal loops. The thermalization rate is computed at one loop level, but an estimate of the two--

A. H. Chamseddine, J. Fröhlich

We consider the standard model in the formulationo of non-commutative geometry, for a Euclidean space-time consisting of two copies. The electroweak scale is set by the vacuum expectation value of a scalar field and is undetermined at the classical level. By adding the Coleman-Weinberg effective potential, that scale turns out to be fixed. Provided that the

C. Bernard, C. Parrinello, A. Soni

We consider pure glue QCD at beta=5.7, beta=6.0 and beta=6.3. We evaluate the gluon propagator both in time at zero 3-momentum and in momentum space. From the former quantity we obtain evidence for a dynamically generated effective mass, which at beta=6.0 and beta=6.3 increases with the time separation of the sources, in agreement with earlier results. The m

A. H. Castro Neto, Eduardo Fradkin

We bosonize a Fermi liquid in any number of dimensions in the limit of long wavelengths. From the bosons we construct a set of coherent states which are related with the displacement of the Fermi surface due to particle-hole excitations. We show that an interacting hamiltonian in terms of the original fermions is quadratic in the bosons. We obtain a path int

Ravi Bhagavatula, C. Jayaprakash

We propose a novel mechanism for the origin of non-Gaussian tails in the probability distribution functions (PDFs) of local variables in nonlinear, diffusive, dynamical systems including passive scalars advected by chaotic velocity fields. Intermittent fluctuations on appropriate time scales in the amplitude of the (chaotic) noise can lead to exponential tai

H. Orland

The Flory theory for a single polymer chain is derived as the lowest order of a cumulant expansion. In this approach, the full original Flory free energy (including the logarithmic term), is recovered. %This term does not change the wandering exponent $ ν$ but turns out to %be responsible for the crossover from Brownian $ (d>4) $ to swollen $ %(d\leq4) $ %re

Michael Eisele, Dieter Mayer

Dynamical zeta functions are expected to relate the Schrödinger operator's spectrum to the periodic orbits of the corresponding fully chaotic Hamiltonian system. The relationsship is exact in the case of surfaces of constant negative curvature. The recently found factorisation of the Selberg zeta function for the modular surface is known to correspond to

Philip D. Mannheim

In the first paper in this series we presented a typical set of galactic rotation curves associated with the conformal invariant fourth order theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. Reasonable agreement with data was obtained for four representative ga

Philip D. Mannheim

We present a simple, closed form expression for the potential of an axisymmetric disk of stars interacting through gravitational potentials of the form $V(r)=-β/r+γr/2$, the potential associated with fundamental sources in the conformal invariant fourth order theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternativ

Andrei Linde

Usually inflation ends either by a slow rolling of the inflaton field, which gradually becomes faster and faster, or by a first-order phase transition. We describe a model where inflation ends in a different way, due to a very rapid rolling (`waterfall') of a scalar field $σ$ triggered by another scalar field $ϕ$. This model looks as a hybrid of chaotic

E. Caurier, A. P. Zuker, A. Poves, G. Martinez-Pinedo

Exact diagonalizations with a minimally modified realistic force lead to detailed agreement with measured level schemes and electromagnetic transitions in $^{48}$Ca, $^{48}$Sc, $^{48}$Ti, $^{48}$V, $^{48}$Cr and $^{48}$Mn. Gamow-Teller strength functions are systematically calculated and reproduce the data to within the standard quenching factor. Their fine

Anthony J. C. Ladd

A new and very general technique for simulating solid-fluid suspensions has been described in a previous paper (Part I); the most important feature of the new method is that the computational cost scales with the number of particles. In this paper (Part II), extensive numerical tests of the method are described; for creeping flows, both with and without Brow

L. F. Cugliandolo, J. Kurchan, F. Ritort

We study numerically the out of equilibrium dynamics of the hypercubic cell spin glass in high dimensionalities. We obtain evidence of aging effects qualitatively similar both to experiments and to simulations of low dimensional models. This suggests that the Sherrington-Kirkpatrick model as well as other mean-field finite connectivity lattices can be used t

Edi Halyo

An effective Lagrangian for the technidilaton and its interactions with matter is constructed. Properties of the technidilaton are compared with those of the Higgs boson. Technidilaton decays and production channels are investigated. Main technidilaton decays are suppressed compared to the Higgs boson and the most important production mechanism is due to glu

R. Mueller, Carlos O. Lousto

We deal with the black hole information loss paradox by showing that the stimulated emission component of the black hole radiation contains information about the initial state of the system. The nonlocal behaviour that allows the recovery of information about the matter that falls behind the horizon appears in a natural way. We calculate the expectation valu

Mark Hindmarsh, Margaret James

By providing a suitable definition of the electromagnetic field off the Higgs vacuum, we show that within the sphaleron there is a monopole-antimonopole pair with quantized charges, and a loop of electromagnetic current. On integration of the relevant charges and currents over the interior in the limit of small $Θ_W$, we recover the standard formula for the

Henryk Woźniakowski

We study the average case complexity of a linear multivariate problem $(\lmp)$ defined on functions of $d$ variables. We consider two classes of information. The first $\lstd$ consists of function values and the second $\lall$ of all continuous linear functionals. Tractability of $\lmp$ means that the average case complexity is $O((1/\e)^p)$ with $p$ indepen

Lee Rudolph

For an oriented link $L \subset S^3 = \Bd\!D^4$, let $χ_s(L)$ be the greatest Euler characteristic $χ(F)$ of an oriented 2-manifold $F$ (without closed components) smoothly embedded in $D^4$ with boundary $L$. A knot $K$ is {\it slice} if $χ_s(K)=1$. Realize $D^4$ in $\C^2$ as $\{(z,w):|z|^2+|w|^2\le1\}$. It has been conjectured that, if $V$ is a nonsingular

Norbert Riedel

It is shown that the complete localization of eigenvectors for the almost Mathieu operator entails the absence of Cantor spectrum for this operator.

Barry Mazur

The author surveys the problem of piecing together integral or rational solutions to Diophantine equations (global structure) from solutions modulo congruences and real solutions (local structure).

Peter B. Kronheimer

A viable and still unproved conjecture states that, if $X$ is a smooth algebraic surface and $C$ is a smooth algebraic curve in $X$, then $C$ realizes the smallest possible genus amongst all smoothly embedded $2$-manifolds in its homology class. A proof is announced here for this conjecture, for a large class of surfaces $X$, under the assumption that the no

Jeff Kahn, Gil Kalai

Let $f(d)$ be the smallest number so that every set in $R^d$ of diameter 1 can be partitioned into $f(d)$ sets of diameter smaller than 1. Borsuk's conjecture was that $f(d)\! =\!d\!+\!1$. We prove that $f(d)\! \ge\! (1.2)^{\sqrt d}$ for large~$d$.

Tan Jiang, Stephen S. -T. Yau

Let $\scr A^*=\{l_1,l_2,\cdots,l_n\}$ be a line arrangement in $\Bbb{CP}^2$, i.e., a collection of distinct lines in $\Bbb{CP}^2$. Let $L(\scr A^*)$ be the set of all intersections of elements of $A^*$ partially ordered by $X\leq Y\Leftrightarrow Y\subseteq X$. Let $M(\scr A^*)$ be $\Bbb{CP}^2-\bigcup\scr A^*$ where $\bigcup\scr A^*= \bigcup\{l_i\colon\ 1\le

Arthur Jaffe, Frank Quinn

Is speculative mathematics dangerous? Recent interactions between physics and mathematics pose the question with some force: traditional mathematical norms discourage speculation, but it is the fabric of theoretical physics. In practice there can be benefits, but there can also be unpleasant and destructive consequences. Serious caution is required, and the

David A. Hoffman

There exist two new embedded minimal surfaces, asymptotic to the helicoid. One is periodic, with quotient (by orientation-preserving translations) of genus one. The other is nonperiodic of genus one.

Raymond C. Heitmann

An example is constructed of a local ring and a module of finite type and finite projective dimension over that ring such that the module is not rigid. This shows that the rigidity conjecture is false.

A. Kovner, P. S. Kurzepa

We extend the bosonization of $2+1$ - dimensional QED with one fermionic flavor performed previously to the case of QED with an induced Chern - Simons term. The coefficient of this term is quantized: $e^2n/8π$, $n\in {\bf Z}$. The fermion operators are constructed in terms of the bosonic fields $A_i$ and $E_i$. The construction is similar to that in the $n=0

S. Chaudhuri, D. Minic

Motivated by the possibility of an effective string description for the infrared limit of pure Yang-Mills theory, we present a toy model for an effective theory of random surfaces propagating in a target space of $D>2$. We show that the scaling exponents for the fixed area partition function of the theory are apparently well behaved. We make some observation

I. Antoniadis

I review the main properties of four-dimensional strings constructed with free-fermions on the world-sheet. In particular I discuss possible model independent low energy predictions related to the existence of states with fractional electric charges, the computation of the string unification scale, the string model building, and the perturbative approach to

Z. Bern, D. C. Dunbar, T. Shimada

String theory implies a relatively modest growth in computational complexity for perturbative gravity calculations as compared to gauge theory calculations, contrary to field theory expectations. An explicit string-based calculation, which would be extremely difficult using conventional techniques, is presented to illustrate this.

M. Drees, M. M. Nojiri

We present a detailed discussion of the elastic scattering of a supersymmetric neutralino off a nucleon or nucleus, with emphasis on the spin--independent interaction. We carefully treat QCD effects on the squark exchange contribution. In particular, we identify a class of terms that survive even in the absence of mixing in both the neutralino and squark sec

H. Baer, C. H. Chen, M. H. Reno

We present a calculation of jet activity associated with pair production of top quarks at hadron colliders and supercolliders. Our approach is based upon a merger of $2\rightarrow 3$ matrix elements with initial and final state parton showers. We tabulate expected multi-jet rates in $t\bar t$ events, and compare with ${\cal O}(α_s^3 )$ matrix element results

W. Buchmüller, Z. Fodor

We investigate the possibility to search for supersymmetry in the scattering of protons and Compton back-scattered laser light. We evaluate the cross sections for inelastic and elastic production of wino pairs for different electron-proton c.m.s. energies. For $\sqrt{s}=1\ TeV$ the cross section exceeds $1\ fb$ for $m_w<190\ GeV$.

Mark Hindmarsh, Robert Brandenberger, Anne-Christine Davies

We analyze the evolution of scalar and gauge fields during first order phase transitions and show how the Kibble mechanism for the formation of topological defects emerges from the underlying dynamics, paying particular attention to problems posed by gauge invariance when a local symmetry is spontaneously broken. We discuss also the application of the mechan

W. Kummer, W. Mödritsch

The expected large mass $m_t$ of the top quark provides for the first time a chance to discuss the bound-states of the corresponding quantum system as the nonabelian generalization of positronium, using the full power of relativistic quantum field theoretic methods which are available for weakly bound systems. Thus our approach differs in principle from the

Howard E. Haber, Ralf Hempfling

In the minimal supersymmetric model (MSSM) all Higgs self-coupling parameters are related to gauge couplings at tree-level. Leading-logarithmic radiative corrections to these quantities can be summed using renormalization group techniques. By this procedure we obtain complete leading-log radiative corrections to the Higgs masses, the CP-even Higgs mixing ang

S. Frixione, M. Mangano, P. Nason, G. Ridolfi

We describe a next-to-leading-order calculation of the fully exclusive parton cross section for the photoproduction of heavy quarks. We use our result to compute quantities of interest for current fixed-target experiments. We discuss heavy-quark total cross sections, distributions and correlations.

T Chou, David R. Nelson

A model predicting the structure of repulsive, spherically symmetric, monodisperse particles confined between two walls is presented. We study the buckling transition of a single flat layer as the double layer state develops. Experimental realizations of this model are suspensions of stabilized colloidal particles squeezed between glass plates. By expanding

Anthony J. C. Ladd

A new and very general technique for simulating solid-fluid suspensions is described; its most important feature is that the computational cost scales linearly with the number of particles. The method combines Newtonian dynamics of the solid particles with a discretized Boltzmann equation for the fluid phase; the many-body hydrodynamic interactions are fully

Karl B. Fisher, Marc Davis, Michael A. Strauss, Amos Yahil

We present analyses of the two-point correlation function derived from an all-sky redshift survey of 5313 galaxies extracted from the Infrared Astronomical Satellite (IRAS) database. The redshift space correlation function ξ(s) is well described by a power law, $ξ(s) = (s/4.53h^{-1}{\rm Mpc})^{-1.28}$, on scales \simlt 20\mpc; on larger scales ξ(s) drops bel