Nonperturbative Condensates in the Electroweak Phase-Transition

We discuss the electroweak phase-transition in the early universe, using non-perturbative flow equations for a computation of the free energy. For a scalar mass above $\sim 70$ GeV, high-temperature perturbation theory cannot describe this transition reliably. This is due to the dominance of three-dimensional physics at high temperatures which implies that the effective gauge coupling grows strong in the symmetric phase. We give an order of magnitude-estimate of nonperturbative effects in reasonable agreement with recent results from electroweak lattice simulations. (Talk given by C. Wetterich at the 3rd Colloque Cosmologie, Paris, June 7-9, 1995, to appear in the proceedings)Comment: 20 pages, LaTeX, 4 figures, Talk given by C. Wetterich at the 3rd Colloque Cosmologie, Paris, June 7-9, 1995, to appear in the proceedings, *** Replaced figure 1 **

Electroweak Phase Transition and Numerical Simulations in the SU(2) Higgs Model

Recent progress in non-perturbative investigations of the electroweak phase transition is reviewed, with special emphasis on numerical simulations in the four-dimen\-sional SU(2) Higgs model.Comment: 11 pages, latex, 2 figures. Lecture given at the $3^e$ Colloque Cosmologie, Paris, June 199

Systematic uncertainties in the precise determination of the strangeness magnetic moment of the nucleon

Systematic uncertainties in the recent precise determination of the strangeness magnetic moment of the nucleon are identified and quantified. In summary, G_M^s = -0.046 \pm 0.019 \mu_N.Comment: Invited presentation at PAVI '04, International Workshop on Parity Violation and Hadronic Structure, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble, France, June 8-11, 2004. 7 pages, 16 figure

Hidden Negative Energies in Strongly Accelerated Universes

We point out that theories of cosmological acceleration which have equation of state, w, such that 1+w is small but positive may still secretly violate the null energy condition. This violation implies the existence of observers for whom the background has infinitely negative energy densities, despite the fact that the perturbations are free of ghosts and gradient instabilities.Comment: 5 pages, 1 figure. v2 reflects version accepted for publication in PRD. Changes: additional discussion of gauge-dependence in perturbed cosmologie

Examples of Berezin-Toeplitz Quantization: Finite sets and Unit Interval

We present a quantization scheme of an arbitrary measure space based on overcomplete families of states and generalizing the Klauder and the Berezin-Toeplitz approaches. This scheme could reveal itself as an efficient tool for quantizing physical systems for which more traditional methods like geometric quantization are uneasy to implement. The procedure is illustrated by (mostly two-dimensional) elementary examples in which the measure space is a $N$-element set and the unit interval. Spaces of states for the $N$-element set and the unit interval are the 2-dimensional euclidean $\R^2$ and hermitian \C^2 planes

String Cosmology: Basic Ideas and General Results

After recalling a few basic concepts from cosmology and string theory, I will outline the main ideas/assumptions underlying (our own group's approach to) string cosmology and show how these lead to the definition of a two-parameter family of ``minimal" models. I will then briefly explain how to compute, in terms of those parameters, the spectrum of scalar, tensor and electromagnetic perturbations, and mention their most relevant physical consequences. More details on the latter part of this talk can be found in Maurizio Gasperini's contribution to these proceedings.Comment: Latex file + 3 figures. Talk presented at the 3rd Colloque Cosmologie, Paris, 7-9 June 9