Executive Summary : | The Ads or CFT correspondence is one of the most celebrated developments in theoretical physics in the last 25 years. The correspondence claims the equivalence of quantum gravity on Anti-de sitter (Ads) spaces to lower dimensional conformal field theories. It famously translates some of the most challenging questions on one side of the correspondence into easier questions on the other side of the correspondence. For example, a version of the correspondence relates strongly coupled large N gauge theory in four dimensions to a weakly coupled gravitational theory in five dimensions. Calculations in the former are challenging due to strong coupling, but in the latter are easy. A challenging problem that has occupied general relativists over the years is the back reaction of quantum fields on black hole spacetimes. Numerous and varied results have been obtained, but no concrete model has been proposed where the back reaction problems can be handled in detail. Ideally, we would like to have a working model where issues related to the quantum entropy of matter can be addressed. Modern developments in holography --- especially in the context of the braneworld holography --- have introduced such models. In these models, all quantum backreaction effects are consistently taken into account. These models have been dubbed quantum black holes and come in a large variety. They are currently being explored in a wide variety of contexts. The present proposal aims to perform a detailed study of such quantum black holes. We wish to understand some of the key features of the quantum nature of spacetime through these models. As we detail below, the topic encompasses some of the most exciting issues in gravitational physics: laws of black hole mechanics with quantum fields, quantum entropy, higher-derivative theories of gravity, extended thermodynamics, black hole chemistry, and issues related to de sitter gravity and much more. |