My research mostly focuses on black hole physics. I have studied integrability properties of higher-dimensional black holes, proposed extended framework for black hole thermodynamics, investigated interactions of black holes with cosmic strings, constructed new black hole solutions.
More specifically, I am interested in higher-dimensional rotating black holes and their integrability properties. I have probed the behavior of particles and fields in their vicinity. I have shown that black holes of spherical horizon topology possess a hidden symmetry of the so called Killing-Yano tensor which in its turn implies complete integrability of geodesic motion and separability of scalar and Dirac equations.
I have co-founded a field of "black hole chemistry" where the thermodynamics of asymptotically AdS black holes is studied in the extended phase space where the cosmological constant is treated as a thermodynamic variable. This leads to a new paradigm where black holes display interesting phenomena known from "every day thermodynamics" of simple substances, such as Van der Waals-like phase transitions, reentrant phase transitions, triple points, isolated critical points, or even superfluidity. Under investigation is the CFT interpretation of the obtained results, via AdS/CFT duality.
I have constructed new black holes solutions that possess non-compact horizons with finite horizon area. Such black holes, for a given thermodynamic volume, possess more entropy than maximally entropic Schwarzschild black holes, hence they are "super-entropic".
More recently, I have studied interactions of cosmic strings with rotating black holes and shown that the backreaction is not described by a mere conical deficit as commonly believed. I have studied thermodynamics of accelerating black holes and shown how the usual laws get extended in the presence of cosmic strings. I also investigated connections between gravity and thermodynamics, reviewing and putting on a firm ground Padmanabhan's proposal on "horizon thermodynamics".