Lectures from the European RTN Winter School on Strings, Supergravity and Gauge Theories, CERN, 16–20 January, 2006

Abstract

This special issue is devoted to the proceedings of the conference'Winter School on Strings, Supergravity and Gauge Theories', whichtook place at CERN, the European Centre for Nuclear Research, inGeneva, Switzerland, from the 16 to the 20 of January 2006.This event was organized in the framework of the European MobilityResearch and Training Network entitled 'Constituents, FundamentalForces and Symmetries of the Universe'. It is part of a yearly seriesof scientific schools which have become a traditional rendezvous for young researchers of the community. The previous one was held at SISSA, in Trieste, Italy, in February 2005, and the next one will take place again at CERN, in January 2007. The school was primarily meant for young doctoral students and postdoctoral researchers working in the area of string theory.It consisted of five general lectures of four hours each, whosenotes are published in the present proceedings, and five workinggroup discussion sessions, focused on specific topics of the networkresearch program. It was attended by approximately 250 participants.The topics of the lectures were chosen to provide an introduction to some of the areas of recent progress and to the open problems in string theory. String theory is expected to provide insights into the description of systems where the role of gravity is crucial. One prominent example of such systems are time-dependent backgrounds with big bang singularities, whose status in string theory is reviewed in the lecture notes by Ben Craps. In another main problem in quantum gravity, string theory gives a fascinating microscopic description of black holes and their properties. The lectures by Shiraz Minwalla review the thermal properties of black holes from their microscopic description in terms of a holographically dual large N field theory.Progress in the description of black hole microstates, and its interplay with the macroscopic description in terms of supergravity solutions via the attractor mechanism, are covered by the lectures by Atish Dabholkar and Boris Pioline. A final important mainstream topic in string theory, being a higher-dimensional theory, is its compactification to four dimensions, and the computation of four-dimensional physical properties in terms of the properties of the internal space. The lectures by Mariana Graña review recent progress in the classification of the most general supersymmetric backgrounds describing the compactified dimensions, and their role in determining the number of massless scalar moduli fields in four dimensions.The conference was financially supported by the European Commissionunder contract MRTN-CT-2004-005104 and by CERN. It was jointlyorganized by the Physics Institute of the University of Neuchâtel and the Theory Unit of the Physics Division of CERN. It is a great pleasure for us to warmly thank the Theory Unit of CERNfor its very kind hospitality and for the high quality of the servicesand infrastructure that it has provided. We also acknowledgehelpful administrative assistance from the Physics Institute of theUniversity of Neuchâtel. Special thanks go finally to Denis Frankfor his very valuable help in preparing the conference web pages,and to J Rostant, A-M Perrin and M-S Vascotto for their continuous and very reliable assistance.