Extremal Rotating Black Holes in the Near-Horizon Limit: Phase Space and Symmetry Algebra

by Mr Kamal Hajian (IPM)

Thursday 28 May 2015, 11:00 → 12:00 Asia/Tehran

Seminar Room (Larak)

In this presentation, I will try to explain the main contents of the recent paper arXiv:1503.07861  (in collaboration with Geoffrey Compere,  Ali Seraj and M.M. Sheikh Jabbari.)

The abstract of the paper is:

We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d-dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R)*U(1)^{d-3} Killing isometries which has vanishing SL(2,R) and constant U(1) charges.

We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries.

In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d > 4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. This phase space and in particular its symmetries might serve as a basis for a semiclassical description of extremal rotating black hole microstates.