Holography Lunch: Yang Lei
Speaker: Yang Lei
Title: Probing EVH limit of supersymmetric AdS black hole
Abstract: Extremal black holes are known to have an AdS2 near-horizon geometry. Interesting dynamics can be introduced to AdS2 by considering a special limit, called the Extremal Vanishing Horizon (EVH) limit. We study the EVH limit of black holes with supersymmetry. These are the solutions whose entropy can be understood by studying the free limit of the dual conformal field theory. Our primary example is the AdS5 black hole in EVH limit, where an AdS3 geometry appears. Similarly, the BTZ geometry appears in the near-EVH limit. We show that the superconformal index can reproduce the near-EVH limit of black hole entropy, which can be understood in terms of free operators in CFT4. By studying the superconformal index, we also see how Virasoro indices emerge in the near-EVH limit.