Black Hole Thermodynamics of Hořava-Lifshitz and IR Modified Ho řava-Lifshitz Gravity Theory

Recently, a renormalizable model of gravity has been proposed by Hoř ava, which might be an ultraviolet completion of general relativity and it reduces to Einstein gravity with a non-vanishing cosmological constant in infrared approximation. Kehagias and Sfetsos have added a relevant operator proportional to the 3D geometry Ricci scalar to the original Hoř ava-Lifshitz theory action, which “softly” deviated from detailed-balance. This does not modify the ultraviolet properties of the theory. However, it modifies the infrared approximation and the Minkowski vacuum can be allowed in the infrared Hořava-Lifshitz gravity theory. The static spherical symmetric black hole solutions have been obtained in the Hořava-Lifshitz and infrared Hořava-Lifshitz gravity theory. Based on the metric of the black holes, Hawking radiation of massless scalar particles is investigated using Damour-Ruffini method. Then the black hole thermodynamics property will also be discussed.     

Caustic Singularity in Ho?ava-Lifshitz Gravity

In this note we search for a family of solutions with Caustic singularity in non relativistic-renormalizable Hořava-Lifshitz (HL) theory without the general covariant. We show that in infrared (IR) limit and with a deviation from λ=1 we have no caustic singularity. Also in ultraviolet (UV) regime and for Ricci flat 3-dimensional (3d) spaces and codimension 1 and for λ≠1 the non linear terms should help bouncing this kind of most dangerous would be caustics. But if 3d curvature does not vanish, higher curvature terms do help caustics even in codimension one. Thus the arguments in (J. Cosmol. Astropart. Phys. 0909:005, 2009) are satisfied correctly.     

Geodesic Stability for Kehagias-Sfetsos Black Hole in Hořava-Lifshitz Gravity via Lyapunov Exponents

By computing the Lyapunov exponent, which is the inverse of the instability time scale associated with this geodesic motion we show that for a general Kehagias-Sfetsos (KS) solution, there is two region of space which in both of them the equatorial timelike geodesics are stable via Lyapunov measure of stability.     

Quantum Entropy of the Schwarzschild Black Hole due to Gravitational Perturbations

The quantum entropies of the Schwarzschild black hole arising from the axial and polar gravitational perturbationsare investigated by using the ‘brick-wall‘ model. It is shown that, although the axial and polar perturbationalpotentials have quite different forms, the black hole entropies due to both the gravitational perturbations.areequialent. We also find that the logarithmic correction, which can be expressed in the form In(An/ε^4), is 30times larger than that of the scalar field.     

Fermions Tunneling and Entropy Correction of Black Hole in Gravity’s Rainbow Space Time

Based on the fermions tunneling method, correction to Bekenstein-Hawking entropy of black hole in gravity’s rainbow space time is discussed. We consider not only the quantum corrections in the single particle action revealing that these are proportional to the usual semiclassical contribution but also the quantum effects of space time arising from the change of energy of probe particles moving in it. The result shows that as the high order terms with respect to ℏ of the action is considered, the first and second corrections, namely the logarithmic term and the inverse area term respectively, are produced. This result is consistent with that of loop quantum gravity and other entropy correction theories.     

Electromagnetic Quasinormal Modes in Hořava-Lifshitz Gravity

The electromagnetic quasinormal modes of Ho?ava-Lifshitz black hole is investigated by means of six-order WKB approach. We in this paper compare the quasinormal modes of this black hole with the charged black hole’s cases (we here take a regular charged black hole and Reissner-Nordström black hole for example). The numerical results of Ho?ava-Lifshitz’s quasinormal modes frequency show that the absolute value of imaginary part decrease as the parameter α increase. The fact means that charge in this spacetime make the quasinormal modes damp at a slower rate.     

Statistical-Mechanical Entropy of Garfinkle-Horowitz-Strominger Black Hole

Taking WKB approximation to solve the scalar field equation in the Garfinkle-Horowitz-Strominger (GHS) black hole spacetime, we can get the classical momenta. Substituting the classical momenta into state density equation corrected by the generalized uncertainty principle, we will obtain the number of quantum states with energy less than ω. It is convergent in the neighborhood of the horizon. Then, it is used to calculate the statistical-mechanical entropy of the scalar field in the GHS black hole spacetime. The calculation shows that the entropy is proportional to the horizon area.     

Natures of Statefinder Parameters and Om Diagnostic for Cardassian Universe in Ho?ava-Lifshitz Gravity

In this work, we have considered Cardassian Universe in Ho?ava-Lifshitz gravity. Four types of Cardassian Universe models i.e., polytropic/power law, modified polytropic, exponential and modified exponential models have been considered for accelerating models. The natures of statefinder parameters, deceleration parameter, Om diagnostic and EoS parameters have been investigated for all types of Cardassian models in Ho?ava-Lifshitz gravity.     

Role of Entropy-Corrected New Agegraphic Dark Energy in Hořava-Lifshitz Gravity

In this work, we have considered the entropy-corrected new agegraphic dark energy (ECNADE) model in Ho?ava-Lifshitz gravity in FRW universe. We have discussed the correspondence between ECNADE and other dark energy models such as DBI-essence, Yang-Mills dark energy, Chameleon field, Non-linear electrodynamics field and hessence dark energy in the context of Ho?ava-Lifshitz gravity and reconstructed the potentials and the dynamics of the scalar field theory which describe the ECNADE.     

Statistical Entropy of Horowitz—Strominger Black Hole

The partition functions of bosonic and fermionic fields in Horowitz-Strominger black hole are derived directly by quantum statistical method.Then via the improved brick-wall method (membrane model),the statistical entropy of black hole is obtained.If a proper parameter is chosen in our result,it is found out that the entropy is proportional to the area of horizon.The stripped term and the divergent logarithmic term in the original brick-wall method no longer exist.The difficulty in solving the wave equations of scalar and Dirac fields is avoided.A new neat way of calculating the entropy of various complicated black holes is offered.     

Holographic Entropy Bound of a Nonstationary Black Hole

In accordance with the holographic principle, by counting the states of the scalar field just at the event horizon of the Vaidya-Bonner black hole, the holographic entropy bound of the black hole is calculated and the Bekenstein- Hawking formula is obtained, With the generalized uncertainty principle, the divergence of state density at event horizon in the ordinary quantum field theory is removed, With the residue theorem, the integral trouble in the calculation is overcome. The present result is quantitatively tenable and the holographic principle is realized by applying the quantum field theory to the black hole entropy problem. Compared with some previous works, it is suggested that the quantum states contributing to black hole entropy should be restricted on the event horizon.     

Black Hole Entropy: Inside or Out?

A trialogue. Ted, Don, and Carlo consider the nature of black hole entropy. Ted and Carlo support the idea that this entropy measures in some sense “the number of black hole microstates that can communicate with the outside world.” Don is critical of this approach, and discussion ensues, focusing on the question of whether the first law of black hole thermodynamics can be understood from a statistical mechanics point of view.     

Entropy Quantization of Reissner-Nordström Black Hole

International Journal of Theoretical Physics - The Hawking temperature and Entropy of Reissner-Nordström (RN) black hole can be derived from energy quantization of the test particle moving...     

Entanglement Entropy of Reissner–Nordstrm Black Hole and Quantum Isolated Horizon

Based on the work of Ghosh and Pereze, who view the black hole entropy as the logarithm of the number of quantum states on the Quantum Isolated Horizon(QIH)§ the entropy of Reissner–Nordstr¨om black hole is studied.According to the Unruh temperature, the statistical entropy of quantum fields under the background of Reissner–Nordstr¨om spacetime is calculated by means of quantum statistics. In the calculations we take the integral from the position of QIH to infinity, so the obtained entropy is the entanglement entropy outside the QIH. In Reissner–Nordstr¨om spacetime it is shown that if only the position of QIH is properly chosen the leading term of logarithm of the number of quantum states on the QIH is equal to the leading term of the entanglement entropy outside the black hole horizon, and both are the Bekenstein–Hawking entropy. The results reveal the relation between the entanglement entropy of black hole and the logarithm of the number of quantum states.     

Entropy of an Extreme Reissner-Nordström Black Hole

The definition of entropy consistent with the Nernst theorem of ordinary thermodynamics contradicts the area theorem, which means the breakdown of weak energy condition in an adiabatic process. Such has never occurred in the ordinary thermodynamics. It implies that the extreme black hole is not so alike as the ordinary system and it cannot be treated as the limit of the non-extreme case. In consideration of the Bose-Einstein condensation of the scalar field, the quantum entropy of an extreme RNBH is proportional to the logarithm of the horizon area plus the logarithmic divergence of is a cutoff near the horizon. It is satisfying that the thermodynamic limit of the quantum entropy approaches zero even if 0.     

Fermion Tunnels of Cylindrical Symmetric Black Hole and?the?Corrected Entropy

Using the method proposed by Banerjee and Majhi, we researched fermion tunneling from cylindrical symmetric black hole, and obtained the correctional entropy. In our work, we first prove that the ratios of the wave function’s components are constants near the horizon, so the reasonable action form of the Dirac equation can then be gotten. From the method beyond semiclassical approximation, we finally calculate the Hawking temperature and correctional entropy.     

Entropy of Dirac Field in Non-stationary and Slowly Changing Reissner-Nordstrom Black Hole

Using the thin film brick-wall model and WKB approximation, the entropy of the Dirac field in the nonstationary and slowly changing Reissner-Nordstrom （R-N） black hole is calculated. The result shows that the entropy of the R-N black hole is still proportional to its surface area if we choose proper cut-off.     

Statistical Entropy of an Acoustic Black Hole in Bose–Einstein Condensates

The entanglement entropy of an acoustic black hole in a Bose-Einstein condensates （BEC） is derived, which is associated with the phonons generated via the Hawking mechanism in a sonic hole. Considering the dispersion relation of a BEC, we recalculate the entanglement entropy of the acoustic black hole by means of statistical method in two limits. We find that the entropy is still proportional to the area of event horizon, but with a coefficient dependent on the infrared cutoff.