Applications of gauge/gravity duality to strongly coupled systems (1/2)

by Dr Johanna Erdmenger (Max Planck-Institut fuer Physik)

Friday 19 Jun 2015, 14:30 → 16:00 Europe/Berlin

SR 2, building 2a (DESY Hamburg)

Based on string theory, gauge/gravity duality provides a new way to relate quantum field theories to gravity. In addition to its intrinsic interest, which consists of a new look at the relation between quantum physics and gravity, it has also significant practical applications. This is due to the fact that gauge/gravity duality maps strongly coupled quantum field theories to weakly coupled gravity theories, which are much more tractable. The purpose of this lecture is to introduce the subject to non-specialists and to present key application examples relevant to elementary particle and condensed matter physics. In the first lecture, we review the basic concepts of gauge/gravity duality by referring to its best understood example, the AdS/CFT correspondence. We briefly introduce conformal field theories (CFT) and Anti-de Sitter spaces (AdS) and outline in non-technical terms how the AdS/CFT correspondence is motivated within string theory. We then discuss more generally the new relation between d-dimensional quantum field theories and d+1-dimensional gravity theories suggested by gauge/gravity duality. Particular aspects are the counting of degrees of freedom on both sides of the correspondence, the concept of entanglement entropy and the relation between a Gaussian probability distribution and the AdS metric.