Entanglement Entropy for the Charged BTZ Black Hole

Using the AdS/CFT correspondence we calculate the explicit form of the entanglement entropy for the charged BTZ black hole. The leading term in the large temperature expansion of the entropy function for this black hole reproduces its Bekenstein-Hawking entropy and the subleading term, representing the first corrections due to quantum entanglement, behaves as a logarithm of the BH entropy.Comment: 5 page

Stringy Generalization of the First Law of Thermodynamics for Rotating BTZ Black Hole with a Cosmological Constant as State Parameter

In this paper we will show that using the cosmological constant as a new thermodynamical state variable, the differential and integral mass formulas of the first law of thermodynamics for asymptotic flat spacetimes can be extended to be used at the two horizons of the (2+1) dimensional BTZ black hole. We also extend this equations to the stringy description of the BTZ black hole, in which two new systems that resemble the right and left modes of effective string theory, are defined in terms of the inner and outer horizons.Comment: 5 page

Time Delay in Gravitational Lensing by a Charged Black Hole of String Theory

We calculate the time delay between different relativistic images formed by the gravitational lensing produced by the Gibbons-Maeda-Garfinkle-Horowitz-Stromiger (GMGHS) charged black hole of heterotic string theory. Modeling the supermassive central objects of some galaxies as GMGHS black holes, numerical values of the time delays are estimated and compared with the correspondient Reissner-Nordstrom black holes . The time difference amounts to hours, thus being measurable and permiting to distinguish between General Relativity and String Theory charged black holes.Comment: 9 page

Introduction to Bosonic String Theory

Introductory Notes in Bosonic String Theory and its Canonical Quantization.Comment: 39 pages, No figures. First Published in Journal Of Theoretic

Area Spectrum of a Rotating Charged Black Hole Solution of Heterotic String Theory

The recent proposal of Maggiore that the periodicity of a black hole may be the origin of area quantization law is analyzed in the context of black holes in string theory. We use the period of motion of an outgoing wave, which is shown to be related to the vibrational frequency of the perturbed black hole, to quantize the horizon areas of a Sen black hole. It is shown that the equally spaced area spectrum takes the same form as the obtained by Zeng et. al. for Schwarzschild and Kerr black holes and the spacing is the same as that obtained through the quasinormal mode frequencies. In order to obtain this result, we do not need to use the small angular momentum assumption which is necessary in the quasinormal mode approach.Comment: 9 pages, no figures. arXiv admin note: text overlap with arXiv:1203.5947 by other author

Entropy for Black Holes in the Deformed Horava-Lifshitz Gravity

We study the entropy of black holes in the deformed Horava-Lifshitz gravity with coupling constant lambda. For lambda=1, the black hole resembles the Reissner-Norstrom black hole with a geometric parameter acting like the electric charge. Therefore, we obtain some differences in the entropy when comparing with the Schwarzschild black hole. Finally, we study the heat capacity and the thermodynamical stability of this solution.Comment: 7 pages, 4 figure

Advance of Planetary Perihelion in Post-Newtonian Gravity

We present an elementary derivation of the planetary advance of the perihelion for a general spherically symmetric line element in the post- newtonian approximation.Comment: 7 pages, no figure

On the Komar Energy and the Generalized Smarr Formula for a Charged Black Hole of Noncommutative Geometry

We calculate the Komar energy $E$ for a charged black hole inspired by noncommutative geometry and identify the total mass ($M_{0}$) by considering the asymptotic limit. We also found the generalized Smarr formula, which shows a deformation from the well known relation $M_{0}-\frac{Q_{0}^{2}}{r}=2ST$ depending on the noncommutative scale length $\ell$

Three Dimensional Charged Black Hole Inspired by Noncommutative Geometry

We find a new charged black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole as the source of matter and a gaussian distribution of electric charge. We deduce the thermodynamical quantities of this black hole and compare them with those of a charged BTZ solution.Comment: 7 page

Geodesic Structure of the Noncommutative Schwarzschild Anti-de Sitter Black Hole I: Timelike Geodesics

By considering particles as smeared objects, we investigate the effects of space noncommutativity on the geodesic structure in Schwarzschild-AdS spacetime. By means of a detailed analysis of the corresponding effective potentials for particles, we find the possible motions which are allowed by the energy levels. Radial and non-radial trajectories are treated and the effects of space noncommutativity on the value of the precession of the perihelion are estimated. We show that the geodesic structure of this black hole presents new types of motion not allowed by the Schwarzschild spacetime.Comment: 17 pages, 6 figure