PoS - Proceedings of Science
Volume 305 - Theoretical Advanced Study Institute Summer School 2017 "Physics at the Fundamental Frontier" (TASI2017) - Weeks 1-4
Introduction to Gauge/Gravity Duality
J. Erdmenger
Full text: pdf
Pre-published on: July 24, 2018
Published on: September 13, 2018
We review how the AdS/CFT correspondence is motivated within string theory, and discuss how it is generalized to gauge/gravity duality. In particular, we highlight the relation to quantum information theory by pointing out that the Fisher information metric of a Gaussian probability distribution corresponds to an Anti-de Sitter space. As an application example of gauge/gravity duality, we present a holographic Kondo model. The Kondo model in condensed matter physics describes a spin impurity interacting with a free electron gas: At low energies, the impurity is screened and there is a logarithmic rise of the resistivity. In quantum field theory, this amounts to a negative beta function for the impurity coupling and the theory flows to a non-trivial IR fixed point. For constructing a gravity dual, we consider a large $N$ version of this model in which the ambient electrons are strongly coupled even before the interaction with the impurity is switched on. We present the brane construction which motivates a gravity dual Kondo model and use this model to calculate the impurity entanglement entropy and the resistivity, which has a power-law behaviour. We also study quantum quenches, and discuss the relation to the Sachdev-Ye-Kitaev model.
DOI: https://doi.org/10.22323/1.305.0001
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.