Complex spinodals and supercritical crossovers in Kerr-Newman-AdS4 black holes
Abstract
We study supercritical crossovers in four-dimensional Kerr-Newman-AdS black holes at fixed angular momentum and charge. From the exact enthalpy, we prove uniqueness of the physical critical point and positivity of the quartic Landau coefficient throughout the charge-rotation family, treating the uncharged Kerr-AdS endpoint in separate scaling variables. An exact quartic reduction determines the coexistence entropies and latent heat throughout the subcritical regime. Above criticality, the two physical spinodals continue as a complex conjugate pair. Their real temperature projection defines a Widom-type line, and varying the charge-rotation ratio assembles these lines into a crossover surface. The Landau cusp fixes the imaginary entropy and temperature to scale with the square root and three-halves powers of the pressure displacement from criticality. The projected fold and the local heat capacity ridge share a critical tangent. We derive their leading quadratic temperature separation and prove that the ridge lies at a higher temperature near criticality. Exact endpoint solutions and numerical continuation check these predictions. The cusp exponents are common to the family, while the crossover temperature depends on the thermodynamic criterion used to define it.
Related
- Thermodynamic Crossovers in Supercritical Matter: One, No One, and One Hundred Thousand
- Parity Isospectrality of the Kerr--Newman--de Sitter Black Hole
- Perturbations of Kerr-Newman black holes: separation and mode stability
- On the Extended Kerr-Newman-Bertotti-Robinson Spacetime: Two Black Holes and a Naked Singularity in Bertotti-Robinson Universe
- Perturbations of a Schwarzschild black hole and Newman-Unti gauge
BibTeX
@misc{lee2026complex,
title = {{Complex spinodals and supercritical crossovers in Kerr-Newman-AdS$_4$ black holes}},
author = {Bum-Hoon Lee and Hocheol Lee and Somyadip Thakur},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24978},
eprint = {2610.24978},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24978},
}
RIS
TY - UNPB
TI - Complex spinodals and supercritical crossovers in Kerr-Newman-AdS_4 black holes
AU - Bum-Hoon Lee
AU - Hocheol Lee
AU - Somyadip Thakur
PY - 2026
DA - 2026/10/18
PB - arXiv
DO - 10.48550/arxiv.2610.24978
UR - https://arxiv.org/abs/2610.24978
AB - We study supercritical crossovers in four-dimensional Kerr-Newman-AdS black holes at fixed angular momentum and charge. From the exact enthalpy, we prove uniqueness of the physical critical point and positivity of the quartic Landau coefficient throughout the charge-rotation family, treating the uncharged Kerr-AdS endpoint in separate scaling variables. An exact quartic reduction determines the coexistence entropies and latent heat throughout the subcritical regime. Above criticality, the two physical spinodals continue as a complex conjugate pair. Their real temperature projection defines a Widom-type line, and varying the charge-rotation ratio assembles these lines into a crossover surface. The Landau cusp fixes the imaginary entropy and temperature to scale with the square root and three-halves powers of the pressure displacement from criticality. The projected fold and the local heat capacity ridge share a critical tangent. We derive their leading quadratic temperature separation and prove that the ridge lies at a higher temperature near criticality. Exact endpoint solutions and numerical continuation check these predictions. The cusp exponents are common to the family, while the crossover temperature depends on the thermodynamic criterion used to define it.
ER -