"Supertranslations and Superrotations at the Black Hole Horizon "

Date: 
Mon, 10/23/2017 - 2:10pm
Location: 
Pupin Hall Theory Center, 8th Floor

Laura Donnay

Harvard University

"Supertranslations and Superrotations at the Black Hole Horizon "

In this talk, we study the asymptotic symmetries in the near-horizon region of non-extremal black holes. By prescribing a physically sensible set of boundary conditions at the horizon, we derive the algebra of asymptotic Killing vectors, which is shown to be infinite-dimensional; it includes two sets of supertranslations and two mutually commuting copies of the Virasoro algebra. We define the surface charges associated to these asymptotic diffeomorphisms. When evaluated on the stationary solutions, the only non-vanishing charges are the zero-modes and one of them is shown to reproduce the Bekenstein-Hawking entropy of Kerr black holes. The limit in which the black hole becomes extremal will also be discussed.