Central extension and black hole entropy

          @misc{ scivideos_PIRSA:19110102,
            doi = {10.48660/19110102},
            url = {https://pirsa.org/19110102},
            author = {Chen, Lin-Qing},
            keywords = {Cosmology, Quantum Fields and Strings, Quantum Gravity},
            language = {en},
            title = {Central extension and black hole entropy},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2019},
            month = {nov},
            note = {PIRSA:19110102 see, \url{https://scivideos.org/index.php/pirsa/19110102}}
          }
          

Abstract

Recent developments on asymptotic symmetries and soft modes have deepened our understanding of black hole entropy and the information paradox. The asymptotic symmetry charge algebra of certain classes of spacetimes could have a nontrivial central extension, which plays a crucial role in black hole physics. The Cardy formula of the asymptotic density of states of the dual CFT has been famously used to reproduce the Bekenstein-Hawking entropy formula. However, without assuming holography, it remains obscure from the point of view of gravity how such a constant on the gravitational phase space encodes the information about the density of black hole microstates, and what the gravitational degrees of freedom accounting for the black hole entropy truly are. I will discuss my ongoing efforts of understanding these questions in the covariant phase space formalism.