R-Charged Black Hole and Neutrino Oscillation

In this paper we consider neutrino oscillation in general curved space-times. Then we calculate neutrino oscillation length in the R-charged black hole background, which is a five dimensional space-time, and compare it with the results of various backgrounds. We obtain effect of the electrical charge corresponding to the chemical potential on the oscillation length.     

Holographic Superconductor of Regular Phantom Black Hole

Holographic superconductors containing a non-minimal derivative coupling for the scalar field in a regular phantom plane symmetric black hole have been considered. We show that the parameter of the regular black hole b as well as the non-minimal derivative coupling parameter η affect the formation of the condensate as well as the conductivity in the superconductor. Moreover, b has a critical value in which the critical temperature T_c increases without a bound.     

Deflection Angle and R-Charged Black Holes

In this paper we consider R-charged black holes with three electrical charges and study deflection angle. We confirmed result of previous study that the black hole charges increased the deflection angle.     

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.     

Holographic Entanglement Entropy of the BTZ Black Hole

We investigate quantum entanglement of gravitational configurations in 3D AdS gravity using the AdS/CFT correspondence. We derive explicit formulas for the holographic entanglement entropy (EE) of the BTZ black hole, conical singularities and regularized AdS₃. The leading term in the large temperature expansion of the holographic EE of the BTZ black hole reproduces exactly its Bekenstein-Hawking entropy S _BH , whereas the subleading term behaves as ln S _BH . We also show that the leading term of the holographic EE for the BTZ black hole can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus. This result indicates that black hole EE is not a fundamental feature of the underlying theory of quantum gravity but emerges when the semiclassical notion of spacetime geometry is used to describe the black hole.     

Holographic Superfluid and STU Model

In this study we consider STU model as dual picture of superfluid. By using AdS/CFT correspondence we obtain sound modes as a function of black hole charge and temperature. We find that the second sound has linear behavior with charge and fourth sound yields to one by increasing black hole charge.     

Holographic p-Wave Superconductors in Quintessence AdS Black Hole Spacetime

We construct a holographic p-wave superconductor model in the background of quintessence AdS black hole with an SU(2) Yang-Mills gauge field and then probe the effects of quintessence on the holographic p-wave superconductor. We investigate the relation between the critical temperature and the state parameter of quintessence, and present the numerical results for electric conductivity. It is shown that the condensation of the vector field becomes harder as the absolute value of the state parameter increases. Unlike the scalar condensate in the s-wave model, the condensation of the vector field in p-wave model can occur in the total value range of the state parameter w_q of quintessence. These results could help us know more about holographic superconductor and dark energy.     

Holographic p-Wave Superconductors in Quintessence AdS Black Hole Spacetime

We construct a holographic p-wave superconductor model in the background of quintessence AdS black hole with an SU(2)Yang–Mills gauge field and then probe the efects of quintessence on the holographic p-wave superconductor.We investigate the relation between the critical temperature and the state parameter of quintessence,and present the numerical results for electric conductivity.It is shown that the condensation of the vector field becomes harder as the absolute value of the state parameter increases.Unlike the scalar condensate in the s-wave model,the condensation of the vector field in p-wave model can occur in the total value range of the state parameter wq of quintessence.These results could help us know more about holographic superconductor and dark energy.     

Quantum Black Hole

Creation of a black hole in quantum cosmology is the third way of black hole formation. In contrast to the gravitational collapse from a massive body in astrophysics or from the quantum fluctuation of matter fields in the very early universe, in the quantum cosmology scenario the black hole is essentially created from nothing. The black hole originates from a constrained gravitational instanton. The probability of creation for all kinds of single black holes in the Kerr-Newman family, at the semiclassical level, is the exponential of the total entropy of the universe, or one quarter of the sum of both the black hole and the cosmological horizon areas. The de Sitter spacetime is the most probable evolution at the Planckian era.     

Black Hole Thermodynamics and Lorentz Symmetry

Recent developments point to a breakdown in the generalized second law of thermodynamics for theories with Lorentz symmetry violation. It appears possible to construct a perpetual motion machine of the second kind in such theories, using a black hole to catalyze the conversion of heat to work. Here we describe and extend the arguments leading to that conclusion. We suggest the inference that local Lorentz symmetry may be an emergent property of the macroscopic world with origins in a microscopic second law of causal horizon thermodynamics.     

Negative Entropy and Black Hole Information

Based on negative entropy in entanglement, it is shown that a single-system Copenhagen measurement protocol is equivalent to the two-system von Neumann scheme with the memory filling up the system with negative information similar to the Dirac sea of negative energy. After equating the two quantum measurement protocols, we then apply this equivalence to the black hole radiation. That is, the black hole evaporation corresponds to the quantum measurement process and the two evaporation approaches, the observable-based single-system and the two-system entanglement-based protocols, can be made equivalent using quantum memory. In particular, the measurement choice θ with the memory state inside the horizon in the entanglement-based scheme is shown to correspond to the observable of the measurement choice θ outside the horizon in the single-system protocol, that is, $\mathcal{O}_{\theta}^{\mathrm{out}} = Q_{\theta}^{\mathrm{in}}$ . This indicates that the black hole as quantum memory is filling up with negative information outside the horizon, and its entropy corresponds to the logarithm of a number of equally probable measurement choices. This shows that the black hole radiation is no different than ordinary quantum theory.     

Edge States and Black Hole Entropy

Black hole entropy in the vielbein formulationof General Relativity, both in three and four space-timedimensions, is considered. We comment on recent progressin black hole entropy calculations and compare it to other approaches that also involvedegrees of freedom at the black hole horizon.     

Casimir Effect and Black Hole Radiation

The gravitational field of a black hole intrinsically creates a potential barrier consisted of two reflecting boundaries; the first one far from the hole and the second one in the vicinity of its horizon. With respect to this fact and assuming the boundaries as good conductors (in view of an observer near the horizon just outside the second boundary), in a series of papers, R.M. Nugayev by considering a conformally coupled massless scalar field and based on the calculations of Candelas and Deutsch (the accelerated-mirror results) has claimed that “...the existence of the potential barrier is as crucial for Hawking evaporation as the existence of the horizon”. In this paper, by taking the same assumptions, through straightforward reasonings, we explicitly show that contrary to this claim, the effects of the first boundary on the black hole radiation are quite negligible. Moreover, the inclusion of the second boundary makes the situation more complicated, because the induced Casimir energy-momentum tensor by this boundary in its vicinity is divergent of order \(\delta ^{-4}\) (δ is the distance to the boundary).     

A New Regular Black Hole

A spherically symmetric uncharged regular black hole is proposed in this paper. The black hole’s density in proportion to $r^{3n}e^{-r^{3n+3}}$ , and the curvature tensor in the region of r=0 keep finity. When n=0 in our model, this spacetime is no other than Dymnikova regular black hole. What’s more, there are better properties in this spacetime when n>0. We then discuss the temperature and Hawking radiation of the black hole’s horizon.     

Kerr-Newman-Kasuya Black Hole Tunnelling Radiation

The radiation of black hole contributes to the shrinking of the event horizon such that the background spacetime should not be fixed. In this study we take into account the self-gravitation effect to study the radiation of Kerr Newman-Kasuya black hole as tunnelling. Using the facts of energy conservation and angular momentum conservation we derive the tunnelling rate and show that the spectrum of the radiation as tunnelling is not purely thermal.     

Braneworld Black Hole Gravitational Lensing

A class of braneworld black holes, which I called as Bronnikov–Melnikov–Dehen(BMD) black holes,are studied as gravitational lenses. I obtain the deflection angle in the strong deflection limit, and further calculate the angular positions and magnifications of relativistic images as well as the time delay between different relativistic images. I also compare the results with those obtained for Schwarzschild and two braneworld black holes, i.e., the tidal Reissner-Nordstr¨om(R-N) and the Casadio–Fabbri–Mazzacurati(CFM) black holes.