Magnetic Brane of Cubic Quasi-Topological Gravity in the Presence of Maxwell and Born-Infeld Electromagnetic Field

The main purpose of the present paper is analyzing magnetic brane solutions of cubic quasi-topological gravity in the presence of a linear electromagnetic Maxwell field and a nonlinear electromagnetic Born-Infeld field. We show that the mentioned magnetic solutions have no curvature singularity and also no horizons, but we observe that there is a conic geometry with a related deficit angle. We obtain the metric function and deficit angle and consider their behavior. We show that the attributes of our solution are dependent on cubic quasi-topological coefficient and the Gauss-Bonnet parameter.Comment: 15 pages and 8 figure

Surface Terms of Quartic Quasitopological Gravity and Thermodynamics of Nonlinear Charged Rotating Black Branes

As in the case of Einstein or Lovelock gravity, the action of quartic quasitopological gravity has not a well-defined variational principle. In this paper, we first introduce a surface term that makes the variation of quartic quasitopological gravity well defined. Second, we present the static charged solutions of quartic quasitopological gravity in the presence of a non linear electromagnetic field. One of the branch of these solutions presents a black brane with one or two horizons or a naked singularity depending on the charge and mass of the solution. The thermodynamic of these black branes are investigated through the use of the Gibbs free energy. In order to do this, we calculate the finite action by use of the counterterm method inspired by AdS/CFT correspondence. Introducing a Smarr-type formula, we also show that the conserved and thermodynamics quantities of these solutions satisfy the first law of thermodynamics. Finally, we present the charged rotating black branes in $(n+1)$ dimensions with $k\leq [n/2]$ rotation parameters and investigate their thermodynamics.Comment: 16 pages, Late

Black Holes in (Quartic) Quasitopological Gravity

We construct quartic quasitopological gravity, a theory of gravity containing terms quartic in the curvature that yields second order differential equations in the spherically symmetric case. Up to a term proportional to the quartic term in Lovelock gravity we find a unique solution for this quartic case, valid in any dimensionality larger than 4 except 8. This case is the highest degree of curvature coupling for which explicit black hole solutions can be constructed, and we obtain and analyze the various black hole solutions that emerge from the field equations in $(n+1)$ dimensions. We discuss the thermodynamics of these black holes and compute their entropy as a function of the horizon radius. We then make some general remarks about $K$-th order quasitopological gravity, and point out that the basic structure of the solutions will be the same in any dimensionality for general $K$ apart from particular cases.Comment: LaTex, 9 figures, 27 pages. A new section on holographic hydrodynamics is added. Introduction and concluding remarks have been revise

Reissner-Nordstr\"om Black Holes in Quintic Quasi-topological Gravity

This paper presents a study on charged black holes in quintic quasi-topological gravity, where we construct numerical solutions and investigate their thermodynamics and conserved quantities. We verify the first law of thermodynamics and compare our findings with that of Einstein gravity. We examine the physical properties of the solutions, considering anti-de Sitter, de Sitter, and flat solutions. Our analysis shows that anti-de Sitter solutions exhibit thermal stability, whereas de Sitter and flat solutions do not. Finally, we discuss the implications of our results and possible future research directions.Comment: 27 pages, 9 Figure