Personal web page : https://scholar.google.fr/citations?user=Y7r_V5YAAAAJ&hl=fr
Laboratory link : https://www.ipht.fr/
Black holes are very interesting objects, whose physics brings Quantum Mechanics and General Relativity, the two pillars of modern physics, into sharp contrast. If one considers black holes quantum-mechanically one can argue that they behave as thermodynamic objects, whose entropy (also known as the Bekenstein-Hawking entropy) is given by the area of the event horizon in units of the Planck length squared. For astrophysical black holes, like that in the center of the Milky Way, this area is quite large, giving a huge entropy S = 10^90. Hence, we expect this black hole to have e^(10^90) microstates.
On the other hand, in Einstein’s General Relativity, black hole solutions are unique. Hence, General Relativity predicts that the black hole has one microstate, while Quantum Mechanics predicts it has e^(10^90). This is the biggest unexplained discrepancy in Theoretical Physics, and is at the root of Hawking’s Black Hole Information Paradox. Using arguments from Quantum Information Theory, it can be shown that this discrepancy can only be resolved if there exists a structure with rather unusual properties that replaces the black-hole horizon.
This thesis has three directions. The first is to analyze the existing examples of such horizon-replacing structure within the framework of the AdS-CFT correspondence. The second is to construct novel horizon-sized structure for supersymmetric and non-supersymmetric black holes. The third is to ascertain whether the existence of this horizon-sized structure has an imprint on the gravitational waves emitted during black-hole mergers and detectable using ground and space-based gravitational-wave detectors.
Applicants are expected to have a solid background in General Relativity and Quantum Field Theory. Knowledge of basic String Theory notions is a bonus.