On the 11th of May UMONS will host the joint high-energy theoretical physics seminars organised by the Service de Physique de l’Univers, Champs et Gravitation of UMONS, the Service de Physique Théorique and the Service de Physique Théorique et Mathématique, both of the ULB, the Theoretical Particle Physics Group of the VUB, the High Energy Physics and Relativistic Field Theory group of the KUL and the International Solvay Institutes.

The speakers will be Alejandra Castro (UvA Amsterdam) and Axel Kleinschimdt (MPI for Gravitational Physics, Potsdam). The first seminar will take place at 11am in the auditorium La Fontaine at the Vesale, while the second seminar will take place in the Mirzakhani room at the De Vinci.

11AM: Axel Kleinschmidt (Venue: room La Fontaine, building Vésale)

The most complicated way of writing D=11 supergravity

Exceptional field theory based on the exceptional group E_n is a way of combining aspects of supergravity in a duality covariant way. It can make the Cremmer-Julia E_n symmetry in 11-n dimensions manifest but can also be seen as a way of rewriting the theory in eleven dimensions, breaking the symmetry in the course of doing so. I will review recent results where this idea is taken to the limiting case with Kac-Moody symmetry E11, highlighting interesting representation-theoretic aspects. Based on work with Guillaume Bossard and Ergin Sezgin.

1:30PM: Alejandra Castro (venue: room Mirzakhani, building De Vinci)

Near AdS_2 spectroscopy

In this talk, I will describe holographic properties of near-AdS_2 spacetimes that arise within spherically symmetric configurations of N=2 4D supergravity, for both gauged and ungauged theories. These theories pose a rich space of AdS_2xS^2 backgrounds, and their responses in the near-AdS_2 region are not universal. I will show that the spectrum of operators dual to the matter fields, and their cubic interactions, are sensitive to the properties of the background and the theory it is embedded in. The properties that have the most striking effect are whether the background is BPS or non-BPS, and if the theory is gauged or ungauged. The resulting differences will have an imprint on the quantum nature of the microstates of near-extremal black holes, reflecting that not all extremal black holes respond equally when kicked away from extremality.