118463412
Topological black holes in Lovelock-Born-Infeld gravity
In this paper, we present topological black holes of third order Lovelock gravity in the presence of cosmological constant and nonlinear electromagnetic Born-Infeld field. Depending on the metric parameters, these solutions may be interpreted as black hole solutions with inner and outer event horizons, an extreme black hole or naked singularity. We investigate the thermodynamics of asymptotically flat solutions and show that the thermodynamic and conserved quantities of these black holes satisfy the first law of thermodynamic. We also endow the Ricci flat solutions with a global rotation and calculate the finite action and conserved quantities of these class of solutions by using the counterterm method. We compute the entropy through the use of the Gibbs-Duhem relation and find that the entropy obeys the area law. We obtain a Smarr-type formula for the mass as a function of the entropy, the angular momenta, and the charge, and compute temperature, angular velocities, and electric potential and show that these thermodynamic quantities coincide with their values which are computed through the use of geometry. Finally, we perform a stability analysis for this class of solutions in both the canonical and the grand-canonical ensemble and show that the presence of a nonlinear electromagneticmore » field and higher curvature terms has no effect on the stability of the black branes, and they are stable in the whole phase space.« less
199678500
Violation of no hair conjecture in Einstein-Maxwell-Higgs system
119193740
Surface terms of quasitopological gravity and thermodynamics of charged rotating black branes
We introduce the surface term for quasitopological gravity in order to make the variational principle of the action well defined. We also introduce the charged black branes of quasitopological gravity and calculate the finite action through the use of the counterterm method. Then we compute the thermodynamic quantities of the black brane solution by use of Gibbs free energy and investigate the first law of thermodynamics by introducing a Smarr-type formula. Finally, we generalize our solutions to the case of rotating charged solutions.
123206943
Hawking Effect with Generalized Uncertainty Principle and Modified Dispersion Relations in de Sitter-Schwarzschild Black Hole
Although the tunneling approach is well established for black hole’s radiation, much works have been done to support the extension of this approach to more general settings. In This letter the Parikh-Kraus-Wilczek tunneling proposal of black hole’s tunneling radiation has been considered. The de Sitter-Schwarzschild black hole’s thermodynamics has been studied based on both, the generalized uncertainty principle and the modified dispersion relations analysis. It is shown that entropy, temperature and the original Parikh-Kraus-Wilczek calculations of the black hole’s tunneling probability receive new corrections. The results of these two alternative approaches are identical if one uses the suitable expansion coefficients.
118643347
Thermodynamics of Rotating Lovelock-Lifshitz Black Branes
We investigate the thermodynamics of rotating Lovelock-Lifshitz black branes. We calculate the conserved and thermodynamic quantities of the solutions and obtain a relation between temperature, angular velocity, energy density, entropy density and angular momentum density. We, also, obtain a Smarr-type formula for the energy density as a function of entropy and angular momentum densities, and show that the thermodynamic quantities calculated in this paper satisfy the first law of thermodynamics. Finally, we investigate the stability of black brane solutions in both canonical and grand-canonical ensemble. We find that the solutions are thermally stable for the solutions with $z\leq n-1$, while they can be unstable for $z>n-1$.
123162229
Generalized uncertainty principle, modified dispersion relation and Reissner–Nordström black hole tunneling radiation
Abstract The Parikh–Kraus–Wilczek tunneling proposal of black hole tunneling radiation is considered. Reissner–Nordstrom black hole thermodynamics is studied according to the generalized uncertainty principle and the modified dispersion relation analysis. It is shown that entropy, temperature and the original Parikh–Kraus–Wilczek calculation of the black hole tunneling probability receive new corrections. The results of these two alternative approaches are identical if one uses the suitable expansion coefficients.
7428020
The reduced phase space of an open string in the background B-field
The problem of an open string in background B-field is discussed. Using the discretized model in details we show that the system is influenced by an infinite number of second class constraints. We interpret the allowed Fourier modes as the coordinates of the reduced phase space. This enables us to compute the Dirac brackets more easily. We prove that the coordinates of the string are non-commutative at the boundaries. We argue that in order to find the Dirac bracket or commutator algebra of the physical variables, one should not expand the fields in terms of the solutions of the equations of motion. Instead, one should impose a set of constraints in suitable coordinates.
118016384
Constraint structure and Hamiltonian treatment of Nappi-Witten model
We investigate the Hamiltonian analysis of Nappi-Witten model (WZW action based on non semi simple gauge group) and find a time dependent non-commutativity by canonical quantization. Our procedure is based on constraint analysis of the model in two parts. A first class analysis is used for gauge fixing the original model following by a second class analysis in which the boundary condition are treated as Dirac constraints. We find the reduced phase space by imposing our second class constraints on the variables in an extended Fourier space.
1539587
Noncommutative Geometry and Classical Orbits of Particles in a Central Force Potential
We investigate the effect of the noncommutative geometry on the classical orbits of particles in a central force potential The relation is implemented through the modified commutation relations [xi,xj] = iθij. Comparison with observations places severe constraints on the value of the noncommutativity parameter.
116202352
Simplifying the algebra of first class constraints, SO(3) as an example