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1.
In this paper, we study quantum corrections to the temperature and entropy of a regular Ayón-Beato-García-Bronnikov black
hole solution by using tunneling approach beyond semiclassical approximation. We use the first law of black hole thermodynamics
as a differential of entropy with two parameters, mass and charge. It is found that the leading order correction to the entropy
is of logarithmic form. In the absence of the charge, i.e., e=0, these corrections approximate the corresponding corrections for the Schwarzschild black hole. 相似文献
2.
In the present work we study (i) the charged black hole in Einstein–Gauss–Bonnet (EGB) theory, known as the Einstein–Maxwell–Gauss–Bonnet
(EMGB) black hole and (ii) the black hole in EGB gravity with a Yang–Mills field. The thermodynamic geometry of these two
black hole solutions has been investigated, using the modified entropy in Gauss–Bonnet theory. 相似文献
3.
We demonstrate how Sakharov's idea of induced gravity allows one to explain the statistical-mechanical origin of the entropy
of a black hole. According to this idea, gravity becomes dynamical as the result of quantum effects in the system of heavy
constituents of the underlying theory.The black hole entropy is related to the properties of the vacuum in the induced gravity
in the presence of the horizon. We obtain the Bekenstein-Hawking entropy by direct counting the states of the constituents. 相似文献
4.
Using Unruh-Verlinde temperature obtained by entropic force, we directly calculate partition functions of quantum field in Schwarzschild spacetime via quantum statistical method and derive the expression of the black hole statistical entropy. In our calculation the lower limit of integral is the location of isolated horizon introduced in loop quantum gravity and the upper limit of integral is infinity. So the obtained entropy is the statistical entropy from isolated horizon to the infinite. In our calculation there are not the cutoff and approximation. The results showed that, as long as proper Immirzi parameters are selected, the entropy obtained by loop quantum gravity is consistent with the quantum statistical entropy outside the black hole horizon. Therefore the black hole entropy is a quantum entanglement entropy outside the isolated horizon. 相似文献
5.
Recently, a renormalizable gravity theory has been proposed by Hořava, and it might be an ultraviolet completion of general
relativity or its infrared modification. Particular limit of the theory allows for the Minkowski vacuum. A spherical asymptotically
flat black hole solution that represents the analogy of Schwarzschild solution of general relativity has been obtained. It
will be very interesting to find the difference between traditional general relativity and Hořava-Lifshitz gravity theory.
The three classical tests of general relativity including gravitational red-shift, perihelion precession of the planet Mercury,
and light deflection in gravitational field in the spherical asymptotically flat black hole solution of infrared modified
Hořava-Lifshitz gravity are investigated. The first order corrections from the standard general relativity is obtained. The
result can be used to limit the parameters in Hořava-Lifshitz gravity and to show the viability of the theory. 相似文献
6.
《New Astronomy》2017
The possible corrections to the thermodynamic quantities of higher dimensional Schwa-rzschild black hole have been investigated by considering the generalized uncertainty principle (GUP) and the modified dispersion relation (MDR) separately. The quantum gravitational corrections to the Hawking temperature, energy and entropy of the black hole have been calculated based on both the GUP and the MDR analysis. The explicit form of the corrections are worked out up to the sixth power of the Planck length. The impacts of GUP and MDR have been used separately to obtain the quantum gravitational corrections to the Cardy-Verlinde (C-V) formula. It has been shown that the usual C-V entropy formula receives some new corrections. Also the renormalized form of the C-V formula has been introduced by redefining Virasoro operator and central charge within both the GUP and the MDR. Through comparison of the corrections obtained from GUP and MDR approaches it has been found that the results of these two alternative approaches should be identical if one uses the suitable expansion coefficients. 相似文献
7.
In this work, we have assumed the generalized Vaidya solution in Lovelock theory of gravity in (n+2)-dimensions. It has been shown that Gauss-Bonnet gravity, dimensionally continued Lovelock gravity and pure Lovelock gravity
can be constructed by suitable choice of parameters. We have investigated the occurrence of singularities formed by the gravitational
collapse in above three particular forms of Lovelock theory of gravity. The dependence of the nature of singularity on the
existence of radial null geodesic for Vaidya space-time has been specially considered. In all the three models, we have shown
that the nature of singularities (naked singularity or black hole) completely depend on the parameters. Choices of various
parameters are shown in tabular form. In Gauss-Bonnet gravity theory, it can be concluded that the possibility of naked singularity
increases with increase in dimensions. In dimensionally continued Lovelock gravity, the naked singularity is possible for
odd dimensions for several values of parameters. In pure Lovelock gravity, only black hole forms due to the gravitational
collapse for any values of parameters. It has been shown that when accretion is taking place on a collapsing object, it is
highly unlikely to get a black hole. Finally on considering the phantom era in the expanding universe it is observed that
there is no possibility of formation of a black hole if we are in the Gauss-Bonnet gravity considering the accreting procedure
upon a collapsing object. 相似文献
8.
There has been a renewed interest in the recent years in the possibility of deviations from the predictions of Newton’s “inverse-square
law” of universal gravitation. One of the reasons for renewing this interest lies in various theoretical attempts to construct
a unified elementary particle theory, in which there is a natural prediction of new forces over macroscopic distances. Therefore
the existence of such a force would only coexist with gravity, and in principle could only be detected as a deviation from
the inverse square law, or in the “universality of free fall” experiments. New experimental techniques such that of Sagnac
interferometry can help explore the range of the Yukawa correction λ≥1014 m where such forces might be present. It may be, that future space missions might be operating in this range which has been
unexplored for very long time. In this paper we derive the basic thermodynamic parameters of such a Yukawa stationary spherically
symmetric black hole. First, the expression for the event horizon of such a black hole is derived, with the help of which
the temperature, entropy and heat capacity of this particular black hole are obtained. We have also obtained analytical expressions
for the change of mass of such black hole, and also its corresponding evaporation time. 相似文献
9.
Mustafa Saltı 《Astrophysics and Space Science》2006,306(4):201-204
We use the teleparallel geometry analog of the Møller energy-momentum complex to calculate the energy distribution (due to matter plus field including gravity) of a charged black hole solution in heterotic string theory. We find the same energy distribution as obtained by Gad who investigated the same problem by using the Møller energy-momentum complex in general relativity. The total energy depends on the black hole mass M and charge Q. The energy obtained is also independent of the teleparallel dimensionless coupling constant, which means that it is valid not only in the teleparallel equivalent of general relativity, but also in any teleparallel model. Furthermore, our results also sustains (a) the importance of the energy-momentum definitions in the evaluation of the energy distribution of a given spacetime and (b) the viewpoint of Lessner that the Møller energy-momentum complex is a powerful concept of energy and momentum. 相似文献
10.
Hawking temperature and entropy of Kerr-Sen black hole as a series with dependence on Plank constant
By assumption of a low-energy string theory in addition to the necessity of the semi-classic expansion on action, we study Hawking temperature and entropy of Kerr-Sen black hole. These subjects, recently have introduced in the literature and consist of the new terms of temperature and entropy as the expansion form with powers of ?. Comparing the results with the high energy black hole demonstrates how the semi-classic approximation affects the thermodynamics of the Kerr-Sen black hole, corrected terms classical action and the entropy. 相似文献
11.
A gravitationless black hole model is proposed in accord with a five-dimensional fully covariant Kaluza-Klein (K-K) theory
with a scalar field, which unifies the four-dimensional Einsteinian general theory of relativity and Maxwellian electromagnetic
theory. It is shown that a dense compact core of a star, when it collapses to a critical density, suddenly turns off or shields
its gravitational field. The core, if its mass exceeds an upper limit, directly collapses into a black hole. Otherwise, the
extremely large pressure, as the gravity is turned off, immediately stops the collapse and drives the mantle material of supernova
moving outward, which leads to an impulsive explosion and forms a neutron star as a remnant. A neutron star can further evolve
into a black hole when it accretes enough matter from a companion star such that the total mass exceeds a lower limit. The
black hole in the K-K theory is gravitationless at the surface because the scalar field is infinitely strong, which varies
the equivalent gravitational constant to zero. In general, a star, at the end of its evolution, is relatively harder to collapse
into a gravitationless K-K black hole than a strong gravitational Schwarzschild black hole. This is consistent with the observation
of some very massive stars to form neutron stars rather than expected black holes. In addition, the gravitationless K-K black
hole should be easier to generate jets than a Schwarzschild black hole. 相似文献
12.
Kourosh Nozari 《Astrophysics and Space Science》2012,341(2):421-427
We study the relation between the existence of the logarithmic prefactor and spacetime dimensionality in black hole entropy relation by a detailed study of a TeV-scale black hole entropy. In a model universe with large extra dimensions and within the Generalized Uncertainty Principle (GUP) framework, we show that probability of black hole production in the Large Hadronic Collider (LHC) decreases for sufficiently large values of the GUP parameter. In this regard, even observation of micro-black holes may be suppressed at TeV energy scale. We determine also the GUP parameter in an extra dimensional scenario by comparing black hole entropy calculated within the GUP and loop quantum gravity frameworks. 相似文献
13.
M. Atiqur Rahman 《Astrophysics and Space Science》2014,350(2):713-719
Following the Parikh and Wilczek semiclassical tunneling method of massless particle, hawking radiation of Schwarzschild-de Sitter (SdS) black hole have been computed using null geodesic method. Purely thermal and quantum gravity corrections have been made and have shown that both the corrections give the same results and all the tunneling rates are related to change of Bekenstein-Hawking entropy of SdS black hole. The results obtained for SdS black hole are also in accordance with Parikh and Wilczek’s opinion and gives a correction to the Hawking radiation of SdS black hole. 相似文献
14.
Michael A. Dopita Marcella Marconi Gisella Clementini Enzo Brocato 《Astrophysics and Space Science》2012,338(1):1-2
In recent papers we had developed a unified picture of black hole entropy and curvature which was shown to lead to Hawking
radiation. It was shown that for any black hole mass, holography implies a phase space of just one quantum associated with
the interior of the black hole. Here we study extremal rotating and charged black holes and obtain unique values for ratios
of angular momentum to entropy, charge to entropy, etc. It turns out that these ratios can be expressed in terms of fundamental
constants in nature, having analogies with other physical systems, like in condensed matter physics. 相似文献
15.
This study is emphasized to explore the validity of generalized second law of thermodynamics in the context of non-linear electrodynamics (magnetic effects only) with Brans-Dicke chameleon scalar field as dark energy candidate. For this purpose, we consider FRW universe model with perfect fluid matter contents. We evaluate matter energy density and magnetic field by taking interacting and non-interacting cases of magnetic field and matter as well as the power law ansatz for scalar field. The validity of this law is discussed by using the first law of thermodynamics for four different horizons: Hubble, apparent, particle and event horizons. We conclude that this law may hold for all four horizons with small positive red-shift when chameleon mechanism is taken into account in Brans-Dicke gravity. Finally, we investigate the statefinders in order to check the viability of the model. 相似文献
16.
In this paper we present a class of non-stationary solutions of Einstein’s field equations describing embedded Vaidya-de Sitter black holes with a cosmological variable function Λ(u). The Vaidya-de Sitter black hole is interpreted as the radiating Vaidya black hole is embedded into the non-stationary de Sitter space with variable Λ(u). The energy-momentum tensor of the Vaidya-de Sitter black hole is expressed as the sum of the energy-momentum tensors of the Vaidya null fluid and that of the non-stationary de Sitter field, and satisfies the energy conservation law. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor. We find the violation of the strong energy condition due to the negative pressure and leading to a repulsive gravitational force of the matter field associated with Λ(u) in the space-time. We also find that the time-like vector field for an observer in the Vaidya-de Sitter space is expanding, accelerating, shearing and non-rotating. It is also found that the space-time geometry of non-stationary Vaidya-de Sitter solution with variable Λ(u) is Petrov type D in the classification of space-times. We also find the Vaidya-de Sitter black hole radiating with a thermal temperature proportional to the surface gravity and entropy also proportional to the area of the cosmological black hole horizon. 相似文献
17.
We study the effects of the generalized uncertainty principle in the tunneling formalism for Hawking radiation to evaluate the quantum-corrected Hawking temperature and entropy for a Kerr black hole. By assumption of a spatially flat universe accompanied with expansion of metric, the modified area and entropy of Kerr black hole are calculated and we could obtain an expression for entropy of black hole that is changing with respect to time and Bekenstein-Hawking temperature. 相似文献
18.
Ahmadjon Abdujabbarov Farruh Atamurotov Yusuf Kucukakca Bobomurat Ahmedov Ugur Camci 《Astrophysics and Space Science》2013,344(2):429-435
The shadow of a rotating black hole with nonvanishing gravitomagnetic charge has been studied. It was shown that in addition to the angular momentum of black hole the gravitomagnetic charge term deforms the shape of the black hole shadow. From the numerical results we have obtained that for a given value of the rotation parameter, the presence of a gravitomagnetic charge enlarges the shadow and reduces its deformation with respect to the spacetime without gravitomagnetic charge. Finally we have studied the capture cross section for massive particles by black hole with the nonvanishing gravitomagnetic charge. 相似文献
19.
Using the quantum statistical method, we calculate quantum statistical entropy between the black hole horizon and the cosmological horizon in Schwarzchild spacetime and derive the expression of quantum statistical entropy in de Sitter spacetime. Under the Unruh-Verlinde temperature of Schwarzchild-de Sitter spacetime in the entropic force views, we obtain the expression of quantum statistical entropy in de Sitter spacetime. It is shown that in de Sitter spacetime quantum statistical entropy is the sum of thermodynamic entropy corresponding black hole horizon and the one corresponding cosmological horizon. And the correction term of de Sitter spacetime entropy is obtained. Therefore, it is confirmed that the black hole entropy is the entropy of quantum field outside the black hole horizon. The entropy of de Sitter spacetime is the entropy of quantum field between the black hole horizon and the cosmological horizon. 相似文献
20.
用在brick模型基础上发展起来的membrane模型 ,计算了缘于任意自旋场的非静态黑洞———Vaidya黑洞的自由能和熵。结果表明 ,玻色子场 (自旋s =1,2 )和费米子场 (自旋s =1/2 )的熵都恰好与黑洞的视界面积成正比 ,这与静态和稳态的情况相同。而且 ,玻色子和费米子场的熵具有相同的形式 ,二者相差一个系数 相似文献