5D Rotating Black Holes and the nAdS$_2$/nCFT$_1$ Correspondence

TL;DR

The paper develops a 5D Einstein–AdS truncation that yields a 2D dilaton–gravity model with two scalars describing the Kerr-AdS$_5$ near-horizon region. Using the nAdS$_2$/nCFT$_1$ framework, it derives the IR AdS$_2$ fixed point, analyzes perturbations, and constructs a holographic renormalization scheme that exposes a Schwarzian boundary action governing IR dynamics. A key finding is the non-universality of the mass gap: although the Schwarzian structure and entropy–temperature relation resemble JT-type systems, the mass gap depends on UV data (the AdS$_5$ radius) and thus differs from simpler dilaton-gravity models. The work also clarifies the UV/IR connection by matching 5D Kerr thermodynamics to the 2D effective theory and discusses residual gauge symmetries and their role in the boundary theory.

Abstract

We study rotating black holes in five dimensions using the nAdS$_2$/nCFT$_1$ correspondence. A consistent truncation of pure Einstein gravity (with a cosmological constant) in five dimensions to two dimensions gives a generalization of the Jackiw-Teitelboim theory that has two scalar fields: a dilaton and a squashing parameter that breaks spherical symmetry. The interplay between these two scalar fields is non trivial and leads to interesting new features. We study the holographic description of this theory and apply the results to the thermodynamics of the rotating black hole from a two dimensional point of view. This setup challenges notions of universality that have been advanced based on simpler models: we find that the mass gap of Kerr-AdS$_5$ corresponds to an undetermined effective coupling in the nAdS$_2$/nCFT$_1$ theory which depends on ultraviolet data.