Quantum general relativity is a perturbatively non-renormalizable theory. Such a theory may make sense only as an effective theory with higher curvature terms supplementing the original action. Also, there could be other non-metrical degrees of freedom that can modify Einstein theory. At IIT Gandhinagar, we work on various modified gravity models, mainly looking for theoretical and observational constraints on the theory's parameters.

Black holes have often provided profound insights into the nature of gravity and the structure of spacetime. The study of the mathematical properties of black objects is a central research theme of contemporary theoretical physics. One of the most intriguing facts about the black hole is associating thermodynamic quantities like entropy and temperature with the black hole event horizon. The gravity research group at IIT Gandhinagar is involved in studying various classical and quantum aspects of black hole thermodynamics and aims to generalize the laws of black hole thermodynamics beyond general relativity.

One of the most interesting theoretical developments in the last few decades in theoretical high energy physics is the discovery of AdS/CFT (Anti-de Sitter/Conformal Field theory) correspondence, also known as the Holography. It is a duality between a strongly coupled quantum field theory and a weakly coupled gravity theory. Besides providing critical insight into the nature of quantum gravity, it provides an alternative way to study quantum field theory in regimes where the usual perturbative tools do not apply. Still, the proper understanding of the inner-workings of Holography eludes us. In recent times, key insights from quantum information theory have helped us shed some important light on the inner-workings of AdS/CFT. Our group at IIT-Gandhinagar uses tools of quantum information theory to study several aspects of AdS/CFT and quantum gravity.

The study of the quantum fields' dynamics in curved spacetime led to remarkable results like Hawking radiation from the black holes. The thermal character of the Hawking radiation and the evaporation of a black hole resulted in the problem of information loss, the non-unitary evolution of a pure quantum state to a mixed one. Our group is interested in research problems related to Hawking radiation and the black hole information paradox. We also use tools from AdS/CFT to study some of these problems.

Within the last decade, tools and techniques from quantum information theory, e.g. entanglement entropy, circuit complexity, bring new perspectives into quantum field theory and are inspiring new questions and research directions. Given the current development in the experiment front, this is a significant direction to pursue. At IIT-Gandhinagar, we actively use tools and techniques from quantum information to uncover various interesting features of quantum field theory.