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Near extremal de Sitter black holes and JT gravity
February 2, 2023 @ 9:30 am - 10:30 am
![CMSA GR Seminar 02.03.23](https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-02.03.23.png)
General Relativity Seminar
Speaker: Chiara Toldo (Harvard)
Title: Near extremal de Sitter black holes and JT gravity
Abstract: In this talk I will explore the thermodynamic response near extremality of charged black holes in four-dimensional Einstein-Maxwell theory with a positive cosmological constant. The latter exhibit three different extremal limits, dubbed cold, Nariai and ultracold configurations, with different near-horizon geometries. For each of these three cases I will analyze small deformations away from extremality, and construct the effective two-dimensional theory, obtained by dimensional reduction, that captures these features. The ultracold case in particular shows an interesting interplay between the entropy variation and charge variation, realizing a different symmetry breaking with respect to the other two near-extremal limits.