R-charged AdS_{5} black holes and large N unitary matrix models
Pallab Basu, Spenta R. Wadia
TL;DR
The paper establishes a nonperturbative gauge/gravity link by mapping the R-charged AdS$_5$ black hole phases to the R-charge sector of large-$N$ ${\cal N}=4$ SYM via an effective unitary matrix model of the thermal Polyakov loop. A crucial result is the logarithmic term in the fixed-charge sector, which decisively shapes the phase structure and enables precise matching of saddle points and critical exponents with the supergravity description, including a cusp catastrophe and a third-order transition. Through analyses at zero, weak, and strong coupling, the work demonstrates consistent multi-saddle dynamics (I, II, III) and universal critical behavior, with explicit double-scaling limits yielding tractable partition-function forms that mirror gravitational thermodynamics. The approach provides a powerful framework for understanding black-hole thermodynamics in AdS via matrix models, and suggests extensions to other charged AdS backgrounds and Kerr-AdS black holes.
Abstract
Using the AdS/CFT, we establish a correspondence between the intricate thermal phases of R-charged AdS_{5} blackholes and the R-charge sector of the N=4 gauge theory, in the large N limit. Integrating out all fields in the gauge theory except the thermal Polyakov line, leads to an effective unitary matrix model. In the canonical ensemble, a logarithmic term is generated in the non-zero charge sector of the matrix model. This term is important to discuss various supergravity properties like i) the non-existence of thermal AdS as a solution, ii) the existence of a point of cusp catastrophe in the phase diagram and iii) the matching of saddle points and the critical exponents of supergravity and those of the effective matrix model.
