scholarly journals Spectroscopy of z=0 Lifshitz Black Hole

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gulnihal Tokgoz ◽  
Izzet Sakalli

We studied the thermodynamics and spectroscopy of a 4-dimensional, z=0 Lifshitz black hole (Z0LBH). Using Wald’s entropy formula and the Hawking temperature, we derived the quasi-local mass of the Z0LBH. Based on the exact solution to the near-horizon Schrödinger-like equation (SLE) of the massive scalar waves, we computed the quasi-normal modes of the Z0LBH via employing the adiabatic invariant quantity for the Z0LBH. This study shows that the entropy and area spectra of the Z0LBH are equally spaced.

2013 ◽  
Vol 91 (1) ◽  
pp. 64-70 ◽  
Author(s):  
J. Sadeghi ◽  
A. Banijamali ◽  
E. Reisi

In this paper, using the Hamilton–Jacobi method we first calculate the Hawking temperature for a Horava–Lifshitz black hole. Then by utilizing the radial null geodesic method we obtain the entropy of such a black hole in four-dimensional space–time. We also consider the effect of back reaction on the surface gravity and compute modifications of entropy and Hawking temperature because of such an effect. Our calculations are for two kinds of Horava–Lifshitz black holes: Kehagias–Sfetsos and Lu–Mei–Pope.


2007 ◽  
Vol 22 (08n09) ◽  
pp. 1627-1648 ◽  
Author(s):  
A. BOUCHAREB ◽  
M. RAMÓN MEDRANO ◽  
N. G. SÁNCHEZ

Combination of both quantum field theory (QFT) and string theory in curved backgrounds in a consistent framework, the string analogue model, allows us to provide a full picture of the Kerr–Newman black hole and its evaporation going beyond the current picture. We compute the quantum emission cross-section of strings by a Kerr–Newman black hole (KNbh). It shows the black hole emission at the Hawking temperature T sem in the early stage of evaporation and the new string emission featuring a Hagedorn transition into a string state of temperature Ts at the last stages. New bounds on J and Q emerge in the quantum string regime (besides the known ones of the classical/semiclassical QFT regime). The last state of evaporation of a semiclassical Kerr–Newman black hole with mass M > m Pl , angular momentum J and charge Q is a string state of temperature Ts, string mass Ms, J = 0 and Q = 0, decaying as usual quantum strings do into all kinds of particles. (Naturally, in this framework, there is no loss of information, (there is no paradox at all).) We compute the string entropy Ss(m, j) from the microscopic string density of states of mass m and spin mode j, ρ(m, j). (Besides the Hagedorn transition at Ts) we find for high j (extremal string states j → m2α′c), a new phase transition at a temperature [Formula: see text], higher than Ts. By precisely identifying the semiclassical and quantum (string) gravity regimes, we find a new formula for the Kerr black hole entropy S sem (M, J), as a function of the usual Bekenstein–Hawking entropy [Formula: see text]. For M ≫ m Pl and J < GM2/c, [Formula: see text] is the leading term, but for high angular momentum, (nearly extremal case J = GM2/c), a gravitational phase transition operates and the whole entropy S sem is drastically different from the Bekenstein–Hawking entropy [Formula: see text]. This new extremal black hole transition occurs at a temperature T sem J = (J/ℏ)T sem , higher than the Hawking temperature T sem .


2014 ◽  
Vol 92 (1) ◽  
pp. 46-50
Author(s):  
De-Jiang Qi

Recently, via adiabatic invariance, Majhi and Vagenas quantized the horizon area of the general class of a static spherically symmetric space–time. Very recently, applying the period of the gravity system with respect to the Euclidean time, Zeng and Liu derived area spectra of a Schwarzschild black hole and a Kerr black hole. It is noteworthy that the preceding methods are not useful for the quasi-normal modes. In this paper, based on those works, and as a further study, adopting near horizon approximation, applying the laws of black hole thermodynamics, we would like to investigate the black hole spectroscopy from a class of Plebański and Demiański space–times by using two different methods. The result shows that the area spectrum of the black hole is [Formula: see text], which confirms the initial proposal of Bekenstein, and the result is consistent with that already obtained by Maggiore with quasi-normal modes.


2015 ◽  
Vol 30 (05) ◽  
pp. 1550016
Author(s):  
Guoping Li ◽  
Tianhu Cheng ◽  
Zhang Li ◽  
Zhongwen Feng ◽  
Xiaotao Zu

Adopting the Hamilton–Jacobi method, we investigated the tunneling radiation of a deform Hořava–Lifshitz black hole, and the original tunneling rate and Hawking temperature are obtained. Based on the generalized uncertainty principle, recent researches imply that the quantum gravity corrected the Dirac equation exactly. Hence, the corrected Dirac equation can express the tunneling behavior of fermions may be more suitable, and meanwhile, the corrected Hawking temperature of the Hořava–Lifshitz black hole is obtained. Comparing with previous results, we find that the Hawking temperature is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we inferred that the Hawking radiation would stop by the reason of the quantum gravity, and the remnant of the black hole exists naturally, also the singularity of the black hole is avoided.


2020 ◽  
Vol 80 (2) ◽  
Author(s):  
S. Sedigheh Hashemi ◽  
Mahdi Kord Zangeneh ◽  
Mir Faizal

Abstract We study quasi-normal modes for a higher dimensional black hole with Lifshitz scaling, as these quasi-normal modes can be used to test Lifshitz models with large extra dimensions. We analyze quasi-normal modes for higher dimensional dilaton-Lifshitz black hole solutions coupled to a non-linear Born–Infeld action. We will analyze the charged perturbations for such a black hole solution. We will first analyze the general conditions for stability analytically, for a positive potential. Then, we analyze this system for a charged perturbation as well as negative potential, using the asymptotic iteration method for quasi-normal modes.


Author(s):  
Michele Maggiore

A comprehensive and detailed account of the physics of gravitational waves and their role in astrophysics and cosmology. The part on astrophysical sources of gravitational waves includes chapters on GWs from supernovae, neutron stars (neutron star normal modes, CFS instability, r-modes), black-hole perturbation theory (Regge-Wheeler and Zerilli equations, Teukoslky equation for rotating BHs, quasi-normal modes) coalescing compact binaries (effective one-body formalism, numerical relativity), discovery of gravitational waves at the advanced LIGO interferometers (discoveries of GW150914, GW151226, tests of general relativity, astrophysical implications), supermassive black holes (supermassive black-hole binaries, EMRI, relevance for LISA and pulsar timing arrays). The part on gravitational waves and cosmology include discussions of FRW cosmology, cosmological perturbation theory (helicity decomposition, scalar and tensor perturbations, Bardeen variables, power spectra, transfer functions for scalar and tensor modes), the effects of GWs on the Cosmic Microwave Background (ISW effect, CMB polarization, E and B modes), inflation (amplification of vacuum fluctuations, quantum fields in curved space, generation of scalar and tensor perturbations, Mukhanov-Sasaki equation,reheating, preheating), stochastic backgrounds of cosmological origin (phase transitions, cosmic strings, alternatives to inflation, bounds on primordial GWs) and search of stochastic backgrounds with Pulsar Timing Arrays (PTA).


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Hsu-Wen Chiang ◽  
Yu-Hsien Kung ◽  
Pisin Chen

Abstract One interesting proposal to solve the black hole information loss paradox without modifying either general relativity or quantum field theory, is the soft hair, a diffeomorphism charge that records the anisotropic radiation in the asymptotic region. This proposal, however, has been challenged, given that away from the source the soft hair behaves as a coordinate transformation that forms an Abelian group, thus unable to store any information. To maintain the spirit of the soft hair but circumvent these obstacles, we consider Hawking radiation as a probe sensitive to the entire history of the black hole evaporation, where the soft hairs on the horizon are induced by the absorption of a null anisotropic flow, generalizing the shock wave considered in [1, 2]. To do so we introduce two different time-dependent extensions of the diffeomorphism associated with the soft hair, where one is the backreaction of the anisotropic null flow, and the other is a coordinate transformation that produces the Unruh effect and a Doppler shift to the Hawking spectrum. Together, they form an exact BMS charge generator on the entire manifold that allows the nonperturbative analysis of the black hole horizon, whose surface gravity, i.e. the Hawking temperature, is found to be modified. The modification depends on an exponential average of the anisotropy of the null flow with a decay rate of 4M, suggesting the emergence of a new 2-D degree of freedom on the horizon, which could be a way out of the information loss paradox.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Panos Betzios ◽  
Nava Gaddam ◽  
Olga Papadoulaki

Abstract We describe a unitary scattering process, as observed from spatial infinity, of massless scalar particles on an asymptotically flat Schwarzschild black hole background. In order to do so, we split the problem in two different regimes governing the dynamics of the scattering process. The first describes the evolution of the modes in the region away from the horizon and can be analysed in terms of the effective Regge-Wheeler potential. In the near horizon region, where the Regge-Wheeler potential becomes insignificant, the WKB geometric optics approximation of Hawking’s is replaced by the near-horizon gravitational scattering matrix that captures non-perturbative soft graviton exchanges near the horizon. We perform an appropriate matching for the scattering solutions of these two dynamical problems and compute the resulting Bogoliubov relations, that combines both dynamics. This allows us to formulate an S-matrix for the scattering process that is manifestly unitary. We discuss the analogue of the (quasi)-normal modes in this setup and the emergence of gravitational echoes that follow an original burst of radiation as the excited black hole relaxes to equilibrium.


2012 ◽  
Vol 709 (3) ◽  
pp. 276-279 ◽  
Author(s):  
E. Abdalla ◽  
Jeferson de Oliveira ◽  
A. Lima-Santos ◽  
A.B. Pavan

2009 ◽  
Vol 677 (3-4) ◽  
pp. 186-189 ◽  
Author(s):  
Jieci Wang ◽  
Qiyuan Pan ◽  
Songbai Chen ◽  
Jiliang Jing

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