Lectures from the CERN Winter School on Strings, Supergravity and Gauge Theories, CERN, 9–13 February 2009

Abstract

This special section is devoted to the proceedings of the conference `Winter School on Strings, Supergravity and Gauge Theories', which took place at CERN, the European Centre for Nuclear Research, in Geneva, Switzerland 9–13 February 2009.This event is part of a yearly series of scientific schools, which represents a well established tradition. Previous events have been held at SISSA, in Trieste, Italy, in February 2005 and at CERN in January 2006, January 2007 and January 2008, and were funded by the European Mobility Research and Training Network `Constituents, Fundamental Forces and Symmetries of the Universe'. The next event will take place again at CERN, in January 2010.The school was primarily meant for young doctoral students and postdoctoral researchers working in the area of string theory.It consisted of several general lectures of four hours each, whose notes are published in this special section, and sixworking group discussion sessions, focused on specific topics of the network research program. It was well attended by over 200 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.One of the most active areas in string theory in recent years has been the AdS/CFT or gauge/gravity correspondence, whichproposes the complete equivalence of string theory on (asymptotically) anti de Sitter spacetimes with certainquantum (gauge) field theories. The duality has recently been applied to understanding the hydrodynamical properties of a hotplasma in gauge theories (like the quark–gluon plasma created in heavy ion collisions at the RHIC experiment at Brookhaven,and soon at the LHC at CERN) in terms of a dual gravitational AdS theory in the presence of a black hole. These developmentswere reviewed in the lecture notes by M Rangamani. In addition, the AdS/CFT duality has been proposed as a tool tostudy interesting physical properties in other physical systems described by quantum field theory, for instance in thecontext of a condensed matter system. The lectures by S Hartnoll provided an introduction to this recent developmentwith an emphasis on the dual holographic description of superconductivity. Finally, ideas inspired by the AdS/CFTcorrespondence are yielding deep insights into fundamental questions of quantum gravity, like the entropy of black holesand its interpretation in terms of microstates. The lectures by S Mathur reviewed the black hole entropy and informationparadox, and the proposal for its resolution in terms of `fuzzball' microstates.Further sets of lectures, not included in this special section, by F Zwirner and V Mukhanov, covered phenomenological aspects ofhigh energy physics beyond the Standard Model and of cosmology. The coming experimental data in these two fields areexpected to foster new developments in connecting string theory to the real world.The conference was financially supported by CERN and partially by the Arnold Sommerfeld Center for Theoretical Physics of theLudwig Maximilians University of Munich. It is a great pleasure for us to warmly thank the Theory Unit of CERN forits very kind hospitality and for the high quality of the assistance and the infrastructures that it has provided. A M Uranga CERN, Switzerland Guest Editor