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arXiv · 2212.14356

Near-Extremal Limits of de Sitter Black Holes

Alejandra Castro·Francesca Mariani·Chiara Toldo
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Abstract

We analyze 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 near-horizon geometries AdS$_2 \times S^2$, dS$_2 \times S^2$, Mink$_2 \times S^2$, respectively. For each of these three cases we analyze small deformations away from extremality, and contrast their response. We also construct the effective two-dimensional theory, obtained by dimensional reduction, that captures these features and we provide a more detailed analysis of the perturbations around the near-horizon geometry for each case. Our results for the ultracold case in particular show an interesting interplay between the entropy variation and charge variation, realizing a different symmetry breaking with respect to the other two near-extremal limits.

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Alejandra Castro, Francesca Mariani, Chiara Toldo. 2022-12-29. Near-Extremal Limits of de Sitter Black Holes. https://doi.org/10.1007/jhep07(2023)131

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