Some non perturbative calculations on spin glasses

Models of spin glasses are studied with a phase transition discontinuous in the Parisi order parameter. It is assumed that the leading order corrections to the thermodynamic limit of the high temperature free energy are due to the existence of a metastable saddle point in the replica formalism. An ansatz is made on the form of the metastable point and its contribution to the free energy is calculated. The Random Energy Model is considered along with the p-spin and the p-state Potts Models in their p < infinity expansion.Comment: 12 pages, LaTe

Primordial Entropy Production and Lambda-driven Inflation from Quantum Einstein Gravity

We review recent work on renormalization group (RG) improved cosmologies based upon a RG trajectory of Quantum Einstein Gravity (QEG) with realistic parameter values. In particular we argue that QEG effects can account for the entire entropy of the present Universe in the massless sector and give rise to a phase of inflationary expansion. This phase is a pure quantum effect and requires no classical inflaton field.Comment: 12 pages, 4 figures, IGCG-07 Pun

Semiclassical collapse of a sphere of dust

The semiclassical collapse of a homogeneous sphere of dust is studied. After identifying the independent dynamical variables, the system is canonically quantised and coupled equations describing matter (dust) and gravitation are obtained. The conditions for the validity of the adiabatic (Born--Oppenheimer) and semiclassical approximations are derived. Further on neglecting back--reaction effects, it is shown that in the vicinity of the horizon and inside the dust the Wightman function for a conformal scalar field coupled to a monopole emitter is thermal at the characteristic Hawking temperature.Comment: LaTeX, 25 pages, no figures, final version accepted for publication in Class. and Quantum Gra

Common European Sales Law (CESL) and Private International Law: Some Critical Remarks

This article is an updated and revised version of the contribution published by the author in XI Anuario Español de Derecho Internacional Privado, 2011, 25-61, under the title: “La Propuesta de Reglamento relativo a una normativa común de compraventa europea y el Derecho internacional privado”.La Propuesta de Reglamento del Parlamento Europeo y del Consejo relativo a una normativa común de compraventa europea de 11 de octubre de 2011 (PCESL) introduce una reglamentación material para algunas compraventas transfronterizas que no desplaza la aplicación de las normas de conflicto (en particular de las contenidas de los Reglamentos “Roma I” y “Roma II”). Al contrario, el instrumento opcional contenido en la Propuesta de Reglamento (CESL) presupone la aplicación de la ley de un Estado miembro, como lex contractus. Una vez escogida por las partes, la CESL desplaza a las normas internas cobre compraventa de la ley del Estado miembro. Esta opción del legislador comunitario plantea numerosos problemas e interrogantes acerca de las relaciones entre la CESL y las normas de Derecho internacional privado y en torno a su coexistencia con otros convenios internacionales y el propio acervo comunitario. El análisis de estas relaciones es el objeto del presente estudio, que permite concluir con una valoración negativa de la competitividad internacional de este nuevo instrumento comunitario.The Proposal for a Regulation of the European Parliament and of the Council on a Common European Sales Law of 11 October 2011 (PCESL) introduces a substantive regulation for some cross-border sales contracts that does not displace the application of conflict-of-laws rules (especially those included in “Rome I” and “Rome II” Regulations). On the contrary, the optional instrument included in the Proposal (CESL) presupposes the application of the law of a Member State as lex contractus. Once the parties have chosen the CESL, this regime prevails over the internal rules on sales contracts of the law of that Member State. The formula used by the European legislator gives rise to many concerns and questions about the relationships between the CESL and the conflict-of-laws rules and about its cohabitation with other international conventions and the European acquis itself. The analysis of these relationships is the subject of this article, which concludes with a negative assessment on the international competitiveness of the new European instrument