Physics Colloquium: Topological Stars in Gravity

Department of Physics is pleased to welcome Dr. Ibou Bah, for an in-person colloquia. Dr. Bah is an assistant professor of Physics and Astronomy at Johns Hopkins University since 2017. He completed my PhD at the University of Michigan, Ann Arbor in 2012.  He went on to work with a joint postdoctoral position at the University of Southern California and The Institut de Physique Théorique at Saclay in France.  In 2015, he joined the University of California, San Diego particle theory group as a UC President’s postdoctoral fellow. 

His general research interest is in theoretical high-energy physics and cosmology.  In his research he explores the relations between quantum field theories, string theory and gravity via the framework of holography.  He is also interested in fundamental aspect of black holes and their role in nature.  

Abstract

In this colloquium I will discuss aspects of microscopic degrees of freedom of gravity as motivated by string theory.  Although these are expected to be generically quantum mechanical, our goal is to understand a class of such states 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 can also model black hole microstates.  I will discuss physical aspects of such constructions.