scholarly journals Observing black holes through superconductors

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Youka Kaku ◽  
Keiju Murata ◽  
Jun Tsujimura

Abstract We propose a way to observe the photon ring of the asymptotically anti-de Sitter black hole dual to a superconductor on the two-dimensional sphere. We consider the electric current of the superconductor under the localized time-periodic external electromagnetic field. On the gravity side, the bulk Maxwell field is sent from the AdS boundary and then diffracted by the black hole. We construct the image of the black hole from the asymptotic data of the bulk Maxwell field that corresponds to the electric current on the field theory side. We decompose the electric current into the dissipative and non-dissipative parts and take the dissipative part for the imaging of the black hole. We investigate the effect of the charged scalar condensate on the image. We obtain the bulk images that indicate the discontinuous change of the size of the photon ring.

2014 ◽  
Vol 29 (02) ◽  
pp. 1450010 ◽  
Author(s):  
S. MIGNEMI

We present a technique for obtaining exact spherically symmetric asymptotically de Sitter (dS) or anti-de Sitter (adS) black hole solutions of dilaton gravity with generic coupling to Maxwell field, starting from asymptotically flat solutions and adding a suitable dilaton potential to the action.


2016 ◽  
Vol 25 (07) ◽  
pp. 1650085 ◽  
Author(s):  
Er-Dong Guo ◽  
Miao Li ◽  
Jia-Rui Sun

We study the dual CFT description of the [Formula: see text]-dimensional Reissner–Nordström-Anti de Sitter (RN-AdS[Formula: see text]) black hole in the large dimension (large [Formula: see text]) limit, both for the extremal and nonextremal cases. The central charge of the dual CFT2 (or chiral CFT1) is calculated for the near-horizon near extremal geometry which possesses an AdS2 structure. Besides, the [Formula: see text]-picture hidden conformal symmetry in the nonextremal background can be naturally obtained by a probe charged scalar field in the large [Formula: see text] limit, without the need to input the usual limits to probe the hidden conformal symmetry. Furthermore, a new dual CFT description of the nonextremal RN-AdS[Formula: see text] black hole is found in the large [Formula: see text] limit and the duality is analyzed by comparing the entropies, the absorption cross-sections and the retarded Green’s functions obtained both from the gravity and the dual CFT sides.


2015 ◽  
Vol 30 (16) ◽  
pp. 1550088 ◽  
Author(s):  
Cosmin Crucean ◽  
Mihaela-Andreea Băloi

We study the theory of interaction between charged scalar field and Maxwell field in de Sitter background. Solving the equation of interacting fields, we define the in–out fields as asymptotic free fields and construct the reduction formalism for scalar field. Then we derive the perturbation expansion of the scattering operator. The first-order transition amplitudes corresponding to particle production from de Sitter vacuum and pair production in an external field are analyzed. We show that all these effects are important only in strong gravitational fields and vanish in the flat limit.


2017 ◽  
Vol 26 (13) ◽  
pp. 1750141 ◽  
Author(s):  
Yang Huang ◽  
Dao-Jun Liu ◽  
Xin-Zhou Li

In this paper, a detailed analysis for superradiant stability of the system composed by a [Formula: see text]-dimensional Reissner–Nordström-anti-de Sitter (RN-AdS) black hole and a reflecting mirror under charged scalar perturbations are presented in the linear regime. It is found that the stability of the system is heavily affected by the mirror radius as well as the mass of the scalar perturbation, AdS radius and the dimension of spacetime. In a higher dimensional spacetime, the degree of instability of the superradiant modes will be severely weakened. Nevertheless, the degree of instability can be magnified significantly by choosing a suitable value of the mirror radius. Remarkably, when the mirror radius is smaller than a threshold value the system becomes stable. We also find that massive charged scalar fields cannot trigger the instabilities in the background of [Formula: see text]-dimensional asymptotically flat RN black hole. For a given scalar charge, a small RN-AdS black hole can be superradiantly unstable, while a large one may be always stable under charged scalar field with or without a reflecting mirror. We also show that these results can be easily expounded and understood with the help of factorized potential analysis.


2014 ◽  
Vol 90 (4) ◽  
Author(s):  
Zhiying Zhu ◽  
Shao-Jun Zhang ◽  
C. E. Pellicer ◽  
Bin Wang ◽  
Elcio Abdalla

Sign in / Sign up

Export Citation Format

Share Document