Beyond AdS Space-times, New Holographic Correspondences and Applications

TL;DR

This thesis develops singularity-free holographic models for Lifshitz and hyperscaling violating phenomena, explores the Schwinger effect and entanglement entropy relations, and investigates black hole solutions in massive gravity with implications for phase transitions.

Contribution

It introduces a new IR singularity resolution for HSV backgrounds, analyzes the Schwinger effect and entanglement entropy phase diagrams, and studies black hole solutions in massive gravity.

Findings

Constructed a singularity-free HSV background with curvature corrections.

Presented phase diagrams linking Schwinger effect and entanglement entropy.

Calculated thermodynamic properties and phase diagrams of black holes in massive gravity.

Abstract

To describe Lifshitz and hyperscaling violating (HSV) phenomena in CM one uses gauge fields on the gravity side which naturally realize the breaking of Lorentz invariance. These gravity constructions often contain naked singularities. In this thesis, we construct a resolution of the infra-red (IR) singularity of the HSV background. The idea is to add squared curvature terms to the Einstein-Maxwell dilaton action to build a flow from $\text{AdS}_4$ in the ultra violate (UV) to an intermediating HSV region and then to an $\text{AdS}_2 \times {\text{R}}^2$ region in the IR. This general solution is free from the naked singularities and would be more appropriate for applications of HSV in physical systems. We also study the Schwinger effect by using the AdS/CFT duality. We present the phase diagrams of the Schwinger effect and also the "butterfly shaped-phase diagrams" of the entanglement entropy for four different confining supergravity backgrounds. Comparing different features of all of these diagrams could point out to a potential relation between the Schwinger effect and the entanglement entropy which could lead to a method of measuring entanglement entropy in the laboratory. Finally, we study the "new massive gravity" theory and the different black hole solutions it admits. We first present three different methods of calculating the conserved charges. Then, by calculating the on-shell Gibbs free energy we construct the Hawking-Page phase diagrams for different solutions in two thermodynamical ensembles. As the massive gravity models are dual to dissipating systems, studying the Hawking-Page diagrams could point out to interesting results for the confinement-deconfinement phase transitions of the dual boundary theories.