What are the microscopic degrees of freedom in quantum gravity and how does the gravitational force emerge from them?
Can we find and solve interesting holographic models of quantum gravity?
What really happens at black hole horizons in quantum gravity?
How hard it is to prepare states in quantum field theory using limited resources and what does it teach us about quantum gravity?
How to describe far from equilibrium quantum fields from first principles? What are patterns of thermalization in quantum field theory?
These are some of the fascinating questions at the frontier of our understanding of the universe that our group is investigating.
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.
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.
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.
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
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.
My interests lie in broadly-understood emergent phenomena in quantum field theories. I am using tools from quantum information science to understand how dynamical spacetime emerges from quantum field theory within holography. I am also studying universal behaviors arising in thermalization processes of quantum fields, such as relativistic hydrodynamics and non-thermal fixed points.
My research interests are in quantum gravity, black hole physics, holography and string theory. In particular, I am driven by the mysteries surrounding black holes and their horizons in quantum gravity. The concrete approach I am pursuing is that of exactly solvable lower-dimensional holographic gravity models (such as Jackiw-Teitelboim (JT) gravity and its cousins), where explicit quantum gravitational calculations can be done and interpreted. This research program is supported by the ERC Starting Grant BHHQG.
My earlier work focused on other aspects of black hole quantum physics, including string theoretic descriptions of the stretched horizon and black hole entropy, and the role of edge states in the entanglement entropy of bulk fields across the black hole horizon.
We will have one or more postdoc positions available to start in the
Fall of 2024.
To apply, please use the joint postdoc application with deadline December 17 2023.
My research is centered on exploring lower-dimensional models of quantum gravity, aiming to extract crucial insights into black hole physics and the quantum characteristics of spacetime beyond the semiclassical realm. One particularly promising avenue is the investigation of JT gravity, which provides an unparalleled level of control, due to the exact solvability of partition functions on diverse topologies and correlators.
Furthermore, my focus extends to understanding the interplay between the first-order formulation of these gravity models and lower-dimensional gauge theories, where intriguing nonperturbative effects can be detected and the computation of interesting observables, such as Wilson lines, can be tackled using diverse techniques, including the application of supersymmetric localization.
More info soon...
Technical and conceptual problems regarding a quantum theory of gravity and a microscopic description of black holes have been solved in the lower-dimensional setting of 2d Jackiw-Teitelboim (JT) gravity. I aim to understand whether the lessons of JT gravity generalize to other related models of lower-dimensional gravity, and to eventually go up in the number of dimensions, starting with 3d first. A unifying approach is to exploit the underlying gauge symmetries.
My research focuses on lower-dimensional models of quantum gravity and their connections with higher-dimensional solutions. In this context, 2d Jackiw-Teitelboim (JT) Gravity is an extremely useful tool at our disposal. This 2-dimensional model is fully solvable and captures the near-horizon dynamics of higher-dimensional near-extremal black hole solutions.
More info soon...
My interests are mainly focused on quantum gravity and quantum information. I am trying to use ideas from information theory to understand how gravity emerges from quantum mechanics. In order to achieve this goal, the key is to understand the gravitational correspondence of some information theoretic concepts, including entanglement, complexity, quantum error correction, etc.
More info soon...
Our group provides several Master's courses in the Physics and Astronomy program.
The group is located on the second floor in the building S9 on Campus Sterre.
Department of Physics and Astronomy
Krijgslaan 281 S9
B-9000 Gent, Belgium