scholarly journals A way of decoupling gravitational sources in pure Lovelock gravity

Author(s):  
Milko Estrada

Abstract We provide an algorithm that shows how to decouple gravitational sources in pure Lovelock gravity. This method allows to obtain several new and known analytic solutions of physical interest in scenarios with extra dimensions and with presence of higher curvature terms. Furthermore, using our method, it is shown that applying the minimal geometric deformation to the Anti de Sitter space time it is possible to obtain regular black hole solutions.

2010 ◽  
Vol 685 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Irina Dymnikova ◽  
Michał Korpusik

2018 ◽  
Vol 27 (11) ◽  
pp. 1843015
Author(s):  
Angel D. D. Masa ◽  
Enesson S. de Oliveira ◽  
Vilson T. Zanchin

The main objective of this work is the construction of regular black hole solutions in the context of the Einstein–Maxwell theory. The strategy is to match an interior regular solution to an exterior electrovacuum solution. With this purpose, we first write explicitly the Einstein field equations for the interior regular region. We take an electrically charged nonisotropic fluid, which presents spherical symmetry and a de Sitter type equation of state, where the radial pressure [Formula: see text] is equal to the negative of energy density [Formula: see text], [Formula: see text]. Then, two solutions for the Einstein equations are built, a regular interior solution for the region with matter satisfying a de Sitter equation of state, and an external solution for the region outside the matter, that corresponds to the Reissner–Nordström metric. To complete the solution we apply the Darmois–Israel junction conditions with a timelike thin shell at the matching surface. It is assumed that the matching surface is composed by a thin shell of matter, i.e. a surface layer in the form of a perfect fluid obeying a barotropic equation of state, [Formula: see text] and [Formula: see text] being the intrinsic pressure and energy density of the shell, respectively, and [Formula: see text] a constant parameter. We show that there are electrically charged regular black hole solutions and other compact objects for specific choices of [Formula: see text] and of the other parameters of the model. Some properties the objects are investigated.


2021 ◽  
pp. 2150108
Author(s):  
Sen Guo ◽  
Ya Ling Huang ◽  
Ke Jiang He ◽  
Guo Ping Li

In this paper, we attempt to further study the heat engine efficiency for the regular black hole (BH) with an anti-de Sitter (AdS) background where the working material is the Hayward–AdS (HAdS) BH. In the extended phase space, we investigate the heat engine efficiency of the HAdS BH by defining the cosmological constant as the thermodynamic pressure P and deriving the mechanical work from the PdV terms. Then, we obtain the relation between the efficiency and the entropy/pressure and plot these function figures. Meanwhile, we compare the relation between the HAdS BH with that of the Bardeen–AdS (BAdS) BH, where it is found that the efficiency of the HAdS BH increases with increase in the magnetic charge q in contrast to that of the BAdS BH decrease with increase in the magnetic charge q. We found that the HAdS BH is more efficient than the BAdS BH, and guess that it is related to the BH structure.


2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Ángel Rincón ◽  
Victor Santos

AbstractIn this work, we investigate the quasinormal frequencies of a class of regular black hole solutions which generalize Bardeen and Hayward spacetimes. In particular, we analyze scalar, vector and gravitational perturbations of the black hole with the semianalytic WKB method. We analyze in detail the behaviour of the spectrum depending on the parameter p/q of the black hole, the quantum number of angular momentum and the s number. In addition, we compare our results with the classical solution valid for $$p = q = 1$$ p = q = 1 .


2020 ◽  
Vol 29 (05) ◽  
pp. 2050032
Author(s):  
Shuang Yu ◽  
Changjun Gao

We construct exact black hole solutions to Einstein gravity with nonlinear electrodynamic field. In these solutions, there are, in general, four parameters. They are physical mass, electric charge, cosmological constant and the coupling constant. These solutions differ significantly from the Reissner–Nordström–de Sitter solution in Einstein–Maxwell gravity with a cosmological constant, due to the presence of coupling constant. For example, some of them are endowed with a topological defect on angle [Formula: see text] and the electric charge of some can be much larger or smaller than their mass by varying the coupling constant. On the other hand, these spacetimes are all asymptotically de Sitter (or anti-de Sitter). As a result, their causal structure is similar to the Reissner–Nordström–de Sitter spacetime. Finally, the investigations on the thermodynamics reveal that the coupling constant except for solution-4 has the opposite effect as temperature on the phase, structure of black holes. Concretely, the phase-space changes from single phase to three phases with the decrease of temperature. On the contrary, it changes from three phases to a single phase with the decrease of coupling constant.


1996 ◽  
Vol 11 (18) ◽  
pp. 1467-1473 ◽  
Author(s):  
MAKOTO NATSUUME ◽  
NORISUKE SAKAI ◽  
MASAMICHI SATO

The SL (2, R)/Z WZW orbifold which describes the (2+1)-dimensional black hole approaching anti-de Sitter space asymptotically. We study the 1 → 1 tachyon scattering off the rotating black hole background and calculate the Hawking temperature using the Bogoliubov transformation.


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