arXiv subjects

A. F. Cardona

Publications and source records attributed to A. F. Cardona.

3 recordsLinked to original sources

arXiv2026

Generalized Thermodynamics and Phase Transitions of Vaidya-adS Black Holes

This work investigates the thermodynamics of non-stationary anti-de Sitter (adS) black holes and their gauge-gravity duals. To model a non-equilibrium process, we employ a time-dependent Vaidya-adS metric to describe the collapse of a null fluid and the subsequent thermalization of the dual field theory. We introduce an effective version of free energy as a quasilocal probe to be used in a dynamical setup. By analyzing how this quantity evolves, we show that a first-order phase transition occurs when the final black-hole mass exceeds the limit established by the Hawking-Page temperature. Furthermore, we demonstrate that the final state only approaches the thermal behavior of the N=4 supersymmetric Yang-Mills theory for mass states much larger than the adS radius. Finally, we compute the boundary energy-momentum tensor using holographic renormalization and compare the resulting energy density with the strong-coupling limit. This demonstrates that the dual description provides a consistent framework for both the equilibrium and non-equilibrium thermodynamics of strongly coupled gauge theories.

hep-th↗

arXiv2026

Hawking atmosphere of anti-de Sitter black holes

This work investigates the semiclassical evolution of the Hawking atmosphere surrounding evaporating, spherically symmetric anti-de Sitter (adS) black holes. We model the evaporation process within a dynamical framework, treating the emission of Hawking radiation as a quantum tunneling process through the black-hole horizon. Using the Parikh-Wilczek tunneling method, we incorporate backreaction effects, with the emission probability being linked to the resulting change in the Bekenstein-Hawking entropy of the black hole. This probability is then used to compute the time-dependent luminosity of the system, revealing significant deviations from ideal blackbody behavior, particularly for small adS black holes. For these objects, the luminosity does not increase with temperature due to strong mass variations during evaporation. To complement this microscopic approach, we compute the renormalized energy-momentum tensor for a quantum field propagating in the Vaidya-adS geometry modelling the evaporation process. Together, these approaches clarify the interplay between geometry, quantum fields, and thermodynamics in shaping the Hawking atmosphere and the evaporation dynamics of black holes in asymptotically adS spacetimes.

gr-qc↗

arXiv2017

Quasinormal modes of generalized Pöschl-Teller potentials

Using algebraic techniques we obtain quasinormal modes and frequencies associated to generalized forms of the scattering Pöschl-Teller potential. This approach is based on the association of the corresponding equations of motion with Casimir invariants of differential representations of the Lie algebra sl(2). In the presented development, highest weight representations are constructed and fundamental states are calculated. An infinite tower of quasinormal mode solutions is obtained by the action of a lowering operator. The algebraic results are used in the analysis of the Cauchy initial value problem associated to the generalized Pöschl-Teller potentials. For the scattering potentials considered, there are no late-time tails and the dynamics is always stable.

gr-qc↗