Eling-Oz Formula for Exotic Hairy Black Holes

Exotic Hairy Black Holes

We study black hole solutions in asymptotically AdS_4 spacetime with scalar hair. Following AdS/CFT dictionary these black holes can be interpreted as thermal states of 2+1 dimensional conformal gauge theory plasma, deformed by a relevant operator. We discover a rich phase structure of the solutions. Surprisingly, we find thermodynamically stable phases with spontaneously broken global symmetries that exist only at high temperatures. These phases are metastable, and join the stable symmetric phase via a mean-field second-order phase transition.

Hairy black resonators and the AdS$_4$ superradiant instability

The superradiant instability of Kerr-AdS black holes is studied by numerically solving the full 3+1 dimensional Einstein equations. We find that the superradiant instability results in a two stage process with distinct initial and secondary instabilities. At the end of the secondary instability the geometry oscillates at several distinct fundamental frequencies -- a multi-oscillating black hole. The multi-oscillating black hole is remarkably close to a black resonator, albeit with a bit of gravitational hair. During the hairy black resonator epoch, the evolution of the horizon area is consiste…

Dyonic ISO(7)规范超引力G₂不变区中的微扰性带毛黑膜

Perturbative Hairy Black Branes in the $G_{2}$-Invariant Sector of Dyonic ISO(7) Gauged Supergravity

该研究在dyonic ISO(7)规范超引力的G₂不变区构造微扰带毛黑膜解，通过小量展开推导微扰方程，计算反作用修正与输运系数，揭示物态方程软化。

通过类比引力实现量子修正和带毛黑洞

Quantum-Corrected and Hairy Black Holes via Analogue Gravity

本研究通过类比引力将带毛黑洞与 Calmet-Kuipers 度规映射到拉瓦尔喷管跨音速流动，利用 Mashhoon 方法分析微扰响应，揭示量子修正与毛状效应的不同作用机制，为黑洞研究提供运动学类比手段。

Exotic compact objects with soft hair

Motivated by the lack of a general parametrization for exotic compact objects, we construct a class of perturbative solutions valid for small (but otherwise generic) multipolar deviations from a Schwarzschild metric in general relativity. We introduce two classes of exotic compact objects, with "soft" and "hard" hair, for which the curvature at the surface is respectively comparable to or much larger than that at the corresponding black-hole horizon. We extend the Hartle-Thorne formalism to relax the assumption of equatorial symmetry and to include deformations induced by multipole moments hig…

Shadows of Kerr black holes with and without scalar hair

For an observer, the Black Hole (BH) shadow is the BH's apparent image in the sky due to the gravitational lensing of nearby radiation, emitted by an external source. A recent class of solutions dubbed Kerr BHs with scalar hair possess smaller shadows than the corresponding Kerr BHs and, under some conditions, novel exotic shadow shapes can arise. Thus, these hairy BHs could potentially provide new shadow templates for future experiments such as the Event Horizon Telescope. In order to obtain the shadows, the backward ray-tracing algorithm is briefly introduced, followed by numerical examples …