A little hair can make a big difference: thermodynamic stability of quasi-bald asymptotically-flat black holes
arXiv:2207.10089 · doi:10.1103/PhysRevD.106.124005
Abstract
The local thermodynamic stability of a black hole (BH) in the canonical ensemble is defined by the positivity of the specific heat at constant global charges. Schwarzschild BHs in thermodynamic equilibrium with an energy reservoir are always unstable against small fluctuations of energy, whereas sufficiently near-extremal Reissner-Nordström/Kerr BHs are stable. One could expect that asymptotically-flat hairy BHs branching off from such stable phases would also be, by continuity, locally thermodynamically stable for vanishingly little hair. We show this is not the case in some models, including scalarized BHs bifurcating from Reissner-Nordström and spinning BHs with synchronized hair bifurcating from Kerr. Specifically, it is found that quasi-bald BHs are locally thermodynamically unstable in the canonical ensemble for all global charges and regardless of being dynamically and entropically preferred over bald ones at fixed global charges.
arXiv comment11 pages, 4 figures. Comments are welcome
References in corpus (18)
- Kerr black holes with scalar hair
- Spontaneous scalarization of black holes and compact stars from a Gauss-Bonnet coupling
- New Gauss-Bonnet black holes with curvature induced scalarization in the extended scalar-tensor theories
- Spontaneous scalarisation of charged black holes
- Kerr black holes with Proca hair
- Spontaneously scalarised Kerr black holes
- Classical and Thermodynamic Stability of Black Branes
- Stability of Black Holes and Black Branes
- Spontaneous scalarisation of charged black holes: coupling dependence and dynamical features
- Kerr black holes with self-interacting scalar hair: hairier but not heavier
- Axionic instabilities and new black hole solutions
- Einstein-Maxwell-scalar black holes: the hot, the cold and the bald
- Einstein-Maxwell-scalar black holes: classes of solutions, dyons and extremality
- Charged black holes with axionic-type couplings: classes of solutions and dynamical scalarisation
- On the inexistence of solitons in Einstein-Maxwell-scalar models
- Spontaneous vectorization of electrically charged black holes
- Stability, Instability, Canonical Energy and Charged Black Holes
- Extremal black holes that are not extremal: maximal warm holes