Integrable black hole dynamics in the asymptotic structure of AdS$_{3}$
Marcela Cárdenas, Francisco Correa, Miguel Pino
TL;DR
This work develops a constructive bridge between integrable systems and AdS$_3$ gravity by imposing relaxed boundary conditions that realize two copies of the AKNS hierarchy as the asymptotic dynamics. Through a Chern-Simons/geometry correspondence, it derives field-dependent Killing vectors, constructs finite (yet integrable) canonical charges, and shows these charges form an abelian algebra guided by AKNS bi-Hamiltonian structure. The analysis yields concrete black hole solutions with nontrivial AKNS charges, computes mass and entropy, and proves that stationary AKNS black holes have a constant temperature governed by a hyperelliptic spectral curve. A KdV/cnoidal example illustrates the spectrum and thermodynamics, highlighting deep links between the geometry of hyperelliptic curves and gravitational thermodynamics. The results offer a new holographic perspective where integrable hierarchies organize boundary dynamics and black hole thermodynamics, with potential extensions to other gauge theories and generalized Gibbs ensembles.
Abstract
This work deepens the study of integrable asymptotic symmetries for AdS$_{3}$. They are given by an infinite set of integrable nonlinear equations known as the Ablowitz-Kaup-Newell-Segur (AKNS) hierarchy, characterized by an also infinite set of abelian conserved charges. We present their field-dependent Killing vectors and the computation of the canonical charges associated to the asymptotic metric, together with their corresponding charge algebra. We study black hole thermodynamics and show that the temperature for stationary black holes falling in the AKNS asymptotics is always constant, even in the case where the solutions are not axisymmetric. This is related to the existence of a hyperelliptic curve, which appears as a fundamental object in many integrable systems. We also present a special solution associated with the Korteweg-de Vries equation, that is a particular case of the AKNS integrable hierarchy. It is presented in the form of a periodic soliton leading to a cnoidal KdV black hole, whose temperature is characterized by two copies of hyperelliptic curves.
