Master equations and stability of Einstein-Maxwell-scalar black holes

Self Cite

We investigate the convergence of relativistic hydrodynamics in charged fluids, within the framework of holography. On the one hand, we consider the analyticity properties of the dispersion relations of the hydrodynamic modes on the complex frequency and momentum plane and on the other hand, we perform a perturbative expansion of the dispersion relations in small momenta to a very high order. We see that the locations of the branch points extracted using the first approach are in good quantitative agreement with the radius of convergence extracted perturbatively. We see that for different values of the charge, different types of pole collisions set the radius of convergence. The latter turns out to be finite in the neutral case for all hydrodynamic modes, while it goes to zero at extremality for the shear and sound modes. Furthermore, we also establish the phenomenon of pole-skipping for the Reissner-Nordström black hole, and we find that the value of the momentum for which this phenomenon occurs need not be within the radius of convergence of hydrodynamics.

Section: Fluctuations Around Equilibriummentioning

confidence: 99%

Section: Fluctuations Around Equilibriummentioning

confidence: 99%

Section: Jhep10(2020)121mentioning

confidence: 99%

Section: Jhep10(2020)121mentioning

confidence: 99%

See 2 more Smart Citations

Quasinormal modes in charged fluids at complex momentum

Jansen

Pantelidou

2020

Self Cite

“…The master equations for AdS5 RN black brane have been found in[30,31]. See also[32] for the case of Einstein-Maxwell-Dilaton black branes.…”

mentioning

confidence: 99%

Complexified quasinormal modes and the pole-skipping in a holographic system at finite chemical potential

Abbasi

Tahery

2020

We develop a method to study coupled dynamics of gauge-invariant variables, constructed out of metric and gauge field fluctuations on the background of a AdS5 Reissner-Nordström black brane. Using this method, we compute the numerical spectrum of quasinormal modes associated with fluctuations of spin 0, 1 and 2, non-perturbatively in μ/T . We also analytically compute the spectrum of hydrodynamic excitations in the small chemical potential limit. Then, by studying the spectral curve at complex momenta in every spin channel, we numerically find points at which hydrodynamic and non-hydrodynamic poles collide. We discuss the relation between such collision points and the convergence radius of the hydrodynamic derivative expansion. Specifically in the spin 0 channel, we find that within the range $$ 1.1\underset{\sim }{<}\mu /T\underset{\sim }{<}2 $$ 1.1 < ∼ μ / T < ∼ 2 , the radius of convergence of the hydrodynamic sound mode is set by the absolute value of the complex momentum corresponding to the point at which the sound pole collides with the hydrodynamic diffusion pole. It shows that in holographic systems at finite chemical potential, the convergence of the hydrodynamic derivative expansion in the mentioned range is fully controlled by hydrodynamic informa- tion. As the last result, we explicitly show that the relevant information about quantum chaos in our system can be extracted from the pole-skipping points of energy density re- sponse function. We find a threshold value for μ/T , lower than which the pole-skipping points can be computed perturbatively in a derivative expansion.

Thermodynamically stable asymptotically flat hairy black holes with a dilaton potential: the general case

Astefanesei

Blázquez-Salcedo

Gomez

et al. 2021

We extend the analysis, initiated in [1], of the thermodynamic stability of four-dimensional asymptotically flat hairy black holes by considering a general class of exact solutions in Einstein-Maxwell-dilaton theory with a non-trivial dilaton potential. We find that, regardless of the values of the parameters of the theory, there always exists a sub-class of hairy black holes that are thermodynamically stable and have the extremal limit well defined. This generic feature that makes the equilibrium configurations locally stable should be related to the properties of the dilaton potential that is decaying towards the spatial infinity, but behaves as a box close to the horizon. We prove that these thermodynamically stable solutions are also dynamically stable under spherically symmetric perturbations.