Time：14:00-15:30, Tuesday, September 3 2024
Venue：E4-233, Yungu Campus
Host：Congjun Wu, ITS
Speaker：Hongguang Liu, Friedrich-Alexander-Universität Erlangen-Nürnberg
Title：Gravitational dust collapse and black holes in general relativity and beyond
Abstract：An outstanding problem in gravitational physics is to understand the final state of gravitational collapse and the formation of black holes or singularities. Dust-filled spacetime is the simplest model to study such a problem. The dynamics of dust-filled spherically symmetric spacetime in general relativity can be described by a first-order quasi-linear partial differential equation (PDE) system that is analogous to fluid dynamics. The characteristics of this PDE system transform the dynamics into a decoupled cosmological model with a Hamiltonian formulation, where the quasi-local Misner-Sharp mass appears naturally. In this talk, I will provide a brief introduction to this system in general relativity. I will then discuss the generalization of such dynamics to modified gravity systems beyond general relativity and their connection to effective descriptions of canonical quantum gravity. As a concrete example, I will present the spherically symmetric solution space of the extended model, which belongs to the mimetic gravity class and collapses to regular black holes.
