Weak Gravity Conjecture of Charged-Rotating-AdS Black Hole Surrounded by Quintessence and String Cloud

A series of corrections to general relativity have recently been applied to find the relationship between entropy and extremality-bound black holes. This relationship has been investigated for many black holes, such as charged AdS, rotating, and massive gravity black holes. We give a minor constant correction to the action and confirm these universal relations for a charged-rotating-AdS black hole. We then examine these calculations for the black hole, surrounded by the quintessence and the cloud of string. In this paper, we evaluate a new universal relation. It means that we find the relation between the extremal mass of the black hole and the factor of cloud string and observe that the corresponding universal relation is well established. We find that the quintessence terms play a very effective role in calculating the mass-charge ratio and concept of weak gravity conjecture of black holes. We note here that the added constant correction is inversely related to the entropy of the black hole. It leads us to see that the mass-to-charge ratio decreases and fully confirms the black hole's weak gravity conjecture (WGC).Comment: 22 pages, 4 figure

Quantum Thermodynamics of an α′\alpha^{\prime}-Corrected Reissner-Nordstr\"om Black Hole

In this paper, we will analyze the effects of $\alpha^{\prime}$ corrections on the behavior of a Reissner-Nordstr\"{o}m black hole. We will calculate the effects of such corrections on the thermodynamics and thermodynamic stability of such a black hole. We will also derived a novel $\alpha^{\prime}$-corrected first law. We will investigate the effect of such corrections on the Parikh-Wilczek formalism. This will be done using cross entropy and Kullback-Leibler divergence between the original probability distribution and the $\alpha^{\prime}$-corrected probability distribution. We will then analyze the non-equilibrium quantum thermodynamics of this black hole. It will be observed that its quantum thermodynamics is corrected due to quantum gravitational corrections. We will use Ramsey scheme for emitted particles to calculate the quantum work distribution for this system. The average quantum work will be related to the difference of $\alpha^{\prime}$-corrected free energies using the Jarzynski equality

Thermal fluctuations of (non)linearly charged BTZ black hole in massive gravity

We consider a charged BTZ black hole in asymptotically AdS space-time of massive gravity to study the effect of the thermal fluctuations on the black hole thermodynamics. We consider the Einstein-Born-Infeld solution and investigate critical points and stability. We also compare the results with the case of Einstein-Maxwell solutions. Besides, we find that thermal fluctuations, which appear as a logarithmic term in the entropy, affect the stability of the black hole and change the phase transition point. Moreover, we study the geometrical thermodynamics and find that the behaviour of the linear Maxwell solution is the same as the nonlinear one.Comment: 25 pages, 25 captioned figures, to appear in IJMP

New Singular and Nonsingular Colliding Wave Solutions in Einstein - Maxwell - Scalar Theory

A technique is given to generate coupled scalar field solutions in colliding Einstein - Maxwell (EM) waves. By employing the Bell - Szekeres solution as seed and depending on the chosen scalar field it is possible to construct nonsingular solutions. If the original EM solution is already singular addition of scalar fields does not make the physics any better. In particular, scalar field solution that is transformable to spherical symmetry is plagued with singularities.Comment: 15 pages, To be published in GR