BH solutions with toroidal horizon in dilaton gravity inspired by power-law electrodynamics: PV criticality and quasinormal modes

2020 ◽  
Vol 35 (27) ◽  
pp. 2050172
Author(s):  
Younes Younesizadeh ◽  
Ali Hassan Ahmed ◽  
Amir A. Ahmad ◽  
Feyzollah Younesizadeh ◽  
Morad Ebrahimkhas

In this work, a new class of black hole solutions in dilaton gravity has been obtained where the dilaton field is coupled with nonlinear Maxwell invariant as a source. The background space–time in this works is considered as the [Formula: see text]-dimensional toroidal metric. In the presence of the dilaton field (for some unique values of [Formula: see text][Formula: see text] a ), the electric field increases as we got farther away from the origin. In the absence of the dilaton field [Formula: see text], the electric field always decreases as one goes farther away from the origin. In the thermodynamical analysis, we obtain the Smarr formula for our solution. We find that the presence of the dilaton field makes the solutions to be locally stable near the origin. Also, this field vanishes the global stability near the origin compared to the no dilaton field case [Formula: see text]. We can say that the dilaton field has a crucial impact on the thermodynamical stability and it is a key factor in stability analysis. We study the quasinormal modes (QNMs) of black hole solutions in dilaton gravity. For this purpose, we use the WKB approximation method upto first order corrections. We have shown the perturbations decay in corresponding diagrams when the dilaton parameter [Formula: see text] and coupling constant [Formula: see text] change. Motivated by the thermodynamical analogy of black holes and Van der Waals liquid/gas systems, in this work, we investigate PV criticality of the obtained solution. We extend the phase space by considering the cosmological constant as thermodynamic pressure. We obtain the equation of state (EOS) and plot the relevant PV [Formula: see text] diagrams. We also present a class of interior solutions corresponding to the exterior solution in dilaton gravity. The solution which is obtained for a linear equation of state is regular and well-behaved at the stellar interior. a Dilaton field representation.

2019 ◽  
Vol 34 (35) ◽  
pp. 1950239 ◽  
Author(s):  
Younes Younesizadeh ◽  
Amir A. Ahmad ◽  
Ali Hassan Ahmed ◽  
Feyzollah Younesizadeh ◽  
Morad Ebrahimkhas

In this work, a new class of slowly rotating black hole solutions in dilaton gravity has been obtained where dilaton field is coupled with nonlinear Maxwell invariant. The background space–time is a stationary axisymmetric geometry. Here, it has been shown that the dilaton potential can be written in the form of generalized three Liouville-type potentials. In the presence of these three Liouville-type dilaton potentials, the asymptotic behavior of the obtained solutions is neither flat nor (A)dS. One bizarre property of the electric field is that the electric field goes to zero when [Formula: see text] and diverges at [Formula: see text]. We show the validity of the first law of thermodynamics in thermodynamic investigations. The local and global thermodynamical stability are investigated through the use of heat capacity and Gibbs free energy. Also, the bounded, phase transition and the Hawking–Page phase transition points as well as the ranges of black hole stability have been shown in the corresponding diagrams. From these diagrams, we can say that the presence of the dilaton field makes the solutions to be locally stable near origin and vanishes the global stability of our solutions. In final thermodynamics analysis, we obtain the Smarr formula for our solution. We will show that the presence of dilaton field brings a new term in the Smarr formula. Also, we find that the dilaton field makes the black hole (AdS) mass to decrease for every fix values of [Formula: see text] (entropy).


2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Tong-Tong Hu ◽  
Shuo Sun ◽  
Hong-Bo Li ◽  
Yong-Qiang Wang

Abstract Motivated by the recent studies of the novel asymptotically global $$\hbox {AdS}_4$$AdS4 black hole with deformed horizon, we consider the action of Einstein–Maxwell gravity in AdS spacetime and construct the charged deforming AdS black holes with differential boundary. In contrast to deforming black hole without charge, there exists at least one value of horizon for an arbitrary temperature. The extremum of temperature is determined by charge q and divides the range of temperature into several parts. Moreover, we use an isometric embedding in the three-dimensional space to investigate the horizon geometry. The entropy and quasinormal modes of deforming charged AdS black hole are also studied in this paper. Due to the existence of charge q, the phase diagram of entropy is more complicated. We consider two cases of solutions: (1) fixing the chemical potential $$\mu $$μ; (2) changing the value of $$\mu $$μ according to the values of horizon radius and charge. In the first case, it is interesting to find there exist two families of black hole solutions with different horizon radii for a fixed temperature, but these two black holes have same horizon geometry and entropy. The second case ensures that deforming charged AdS black hole solutions can reduce to standard RN–AdS black holes.


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 .


2007 ◽  
Vol 22 (26) ◽  
pp. 4849-4858 ◽  
Author(s):  
A. SHEYKHI ◽  
N. RIAZI

We consider charged black holes with curved horizons, in five-dimensional dilaton gravity in the presence of Liouville-type potential for the dilaton field. We show how, by solving a pair of coupled differential equations, infinitesimally small angular momentum can be added to these static solutions to obtain charged rotating dilaton black hole solutions. In the absence of dilaton field, the nonrotating version of the solution reduces to the five-dimensional Reissner–Nordström black hole, and the rotating version reproduces the five-dimensional Kerr–Newman modification thereof for small rotation parameter. We also compute the angular momentum and the angular velocity of these rotating black holes which appear at the first order.


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.


1993 ◽  
Vol 08 (08) ◽  
pp. 697-710 ◽  
Author(s):  
X. SHEN

Recently, models of two-dimensional dilaton gravity have been shown to admit classical black hole solutions that exhibit Hawking radiation at the semiclassical level. These classical and semiclassical analyzes have been performed in conformal gauge. We show in this paper that a similar analysis in the light-cone gauge leads to the same results. Moreover, quantization of matter fields in light-cone gauge can be naturally extended to include quantizing the metric field à la KPZ. We argue that this may provide a new framework to address many issues associated to black hole physics.


2020 ◽  
Vol 35 (23) ◽  
pp. 2050193
Author(s):  
Cai-Ying Shao ◽  
Yu Hu ◽  
Yu-Jie Tan ◽  
Cheng-Gang Shao ◽  
Kai Lin ◽  
...  

In this paper, we study the quasinormal modes of the massless Dirac field for charged black holes in Rastall gravity. The spherically symmetric black hole solutions in question are characterized by the presence of a power-Maxwell field, surrounded by the quintessence fluid. The calculations are carried out by employing the WKB approximations up to the 13th-order, as well as the matrix method. The temporal evolution of the quasinormal modes is investigated by using the finite difference method. Through numerical simulations, the properties of the quasinormal frequencies are analyzed, including those for the extremal black holes. Among others, we explore the case of a second type of extremal black holes regarding the Nariai solution, where the cosmical and event horizon coincide. The results obtained by the WKB approaches are found to be mostly consistent with those by the matrix method. It is observed that the magnitudes of both real and imaginary parts of the quasinormal frequencies increase with increasing [Formula: see text], the spin–orbit quantum number. Also, the roles of the parameters [Formula: see text] and [Formula: see text], associated with the electric charge and the equation of state of the quintessence field, respectively, are investigated regarding their effects on the quasinormal frequencies. The magnitude of the electric charge is found to sensitively affect the time scale of the first stage of quasinormal oscillations, after which the temporal oscillations become stabilized. It is demonstrated that the black hole solutions for Rastall gravity in asymptotically flat spacetimes are equivalent to those in Einstein gravity, featured by different asymptotical spacetime properties. As one of its possible consequences, we also investigate the behavior of the late-time tails of quasinormal models in the present model. It is found that the asymptotical behavior of the late-time tails of quasinormal modes in Rastall theory is governed by the asymptotical properties of the spacetimes of their counterparts in Einstein gravity.


1995 ◽  
Vol 10 (05) ◽  
pp. 367-378 ◽  
Author(s):  
M. CADONI ◽  
S. MIGNEMI

We discuss the properties of Lorentzian and Euclidean black hole solutions of a generalized two-dimensional dilaton gravity action containing a modulus field, which arises from the compactification of heterotic string models. The duality symmetries of these solutions are also investigated.


Sign in / Sign up

Export Citation Format

Share Document