Research
Lower-dimensional Quantum Gravity
Our group has been actively involved in constructing and solving lower-dimensional model of quantum gravity and holography. In particular, the Jackiw-Teitelboim (JT) model is an extremely useful and fully solvable model of 2d quantum gravity.
In our group, we have performed crucial quantum gravitational computations in this model, with deep lessons concerning black hole horizons, local bulk observers' experiences, Hawking's black hole information paradox, and the role of spacetime wormholes. This is a state-of-the-art research program that is attracting much attention internationally, and is being pursued in parallel at many high-tier universities globally.
Edge States and Black Hole Horizons in String Theory
Black hole horizons are ill-understood in quantum gravity. And in particular string theory, as the leading candidate of quantum gravity, should shed light on this issue.
In our group, we have provided evidence for Susskind's picture of long strings that envelop the black hole horizon and can correctly account for the black hole entropy.
A rather confusing role is played by open strings ending on the black hole horizon, which has an avatar in higher spin (s > 1/2) theories in a black hole geometry as so-called edge states. In our group, we aim to clarify the role and interpretation of these edge modes and their relation to the black hole entropy problem.
Complexity in Quantum Field Theory and Gravity
One of the poorest understood aspect of quantum gravity is understanding properties of something as basic as a volume of spacetime.
About 10 years ago in a class of quantum gravity theories it was conjectured that such objects express hardness of state preparation using limited resources in underlying quantum mechanical descriptions, which include primarily quantum field theories.
The group proposed how to define such a notion of complexity for quantum fields, studied its properties and recently made first steps in establishing its gravitational counterpart.
Hydrodynamic Attractors
Relativistic hydrodynamics till recently was thought to arise in thermalization of quantum fields only when these systems are already very close to local thermal equilibrium.
The group introduced and has been studying novel notions of fluidity called hydrodynamic attractors that generalize relativistic hydrodynamics to a far from equilibrium regime. These studies are relevant for theoretical understanding of high energy nuclear collisions at RHIC and LHC accelerators
Nonthermal Fixed Points
One of the most fascinating aspects of thermalization processes of quantum fields is the emergence of self-similar behaviors in time. Such nonthermal fixed points were recently experimentally realized in cold atoms experiments and were earlier shown to play an important role in thermalization in nuclear collisions when the QCD coupling is weak.
The group studies these objects using ideas and techniques originating from the strong coupling framework of holography.
