Online Seminar〝The boundary problem in (super)gravity from a geometric perspective〞

Star-UBB Seminar Series:- The boundary problem in (super)gravity from a geometric perspective

The speaker will discuss the boundary problem in gravity and supergravity, retracing the geometric construction of four-dimensional (super)gravity Lagrangians with negative cosmological constant on a manifold with boundary. The presence of a spacetime boundary breaks diffeomorphisms (and supersymmetry) invariance of the action. To recover such invariance, it is necessary to modify the theory by adding appropriate boundary contributions to the Lagrangian, which, in the gravity case, correspond to the Euler-Gauss-Bonnet term and, in supergravity, to its supersymmetric extension. The full Lagrangian can be recast in a MacDowell-Mansouri form. Regarding the supergravity side, The speaker will also consider the case of vanishing cosmological constant in the presence of a non-trivial boundary, where the inclusion of boundary terms involving additional fields, which behave as auxiliary fields for the bulk theory, allows to restore supersymmetry. She will eventually report on the application of the results to specific problems regarding cases where the boundary is located asymptotically.

時間:2023.05.25(四) 16:00~17:00
頻道:Zoom ID:853-7454-4159 ←
講者:Prof. Lucrezia Ravera (Department of Applied Science and Technology, Politecnico di Torino(Turin Polytechnic), Italy)


Scientific and Technological Advanced Research- Babeș-Bolyai University(Star-UBB) Seminar Series in Gravitation, Cosmology and Astrophysics

Presently a period of rapid and intense change are being witnessed in our understanding of the gravitational force, at a rate that is quickly increasing since the important observational discoveries of the late 1990s. With the advent of new observational techniques, the emergence of important cosmological and astrophysical paradigms can be seen that lead to a deep change in our understanding of the Universe. Astronomical observations strongly suggest that at large scales the force of gravity may not behave according to standard general relativity, and that a generalization of the gravitational action, either at the geometric level, or at the matter level, may be required for a full understanding of the gravitational interaction.

The goal of the present seminar is to bring Theoretical Gravitational Physics closer to the observations and experiments, and to discuss current topics in general relativity, high-energy physics, astrophysics and cosmology.


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