Theory Group Seminar, 06 April 2021

Ibou Bah, John Hopkins University

Topological Stars and Black Holes

abstract

In this seminar I will discuss aspects of microscopic degrees of freedom of black holes as motivated by string theory. Although these are expected to be generically quantumly, our goal is to understand a class of black hole microstates that are coherent enough to admit classical descriptions in Einstein gravity. The construction of such states corresponds to adding interesting topological structures in spacetime with the help of compact extra dimensions. The constructions manifestly behave like ultra compact objects, dubbed topological stars, which look like black holes far away. I will discuss their potential astrophysical relevance and why it is interesting to understand such objects in a new age of gravitational waves astrophysics.