Modified gravity and the stability of de Sitter space

‎Spacelike hypersurfaces with constant $S$ or $K$ in de Sitter‎ ‎space or anti-de Sitter space

‎Let $M^n$ be an $n(ngeq 3)$-dimensional complete connected and‎ ‎oriented spacelike hypersurface in a de Sitter space or an anti-de‎ ‎Sitter space‎, ‎$S$ and $K$ be the squared norm of the second‎ ‎fundamental form and Gauss-Kronecker curvature of $M^n$‎. ‎If $S$ or‎ ‎$K$ is constant‎, ‎nonzero and $M^n$ has two distinct principal‎ ‎curvatures one of which is simple‎, ‎we obtain some‎ ‎charact...

Super algebra and Harmonic Oscillator in Anti de Sitter space

The harmonic oscillator in anti de Sitter space(AdS) is discussed. We consider the harmonic oscillator potential and then time independent Schrodinger equation in AdS space. Then we apply the supersymmetric Quantum Mechanics approach to solve our differential equation. In this paper we have solved Schrodinger equation for harmonic oscillator in AdS spacetime by supersymmetry approach. The shape...

Cohomogeneity One Anti De Sitter Space H_1^3

ترمودینامیک سیاهچاله‌های چرخان و گرانش با تصحیحات مرتبه اول نظریه ریسمان

  In this paper, the rotating black brane solutions with zero curvature horizon of classical gravity with first order string corrections are introduced. Although these solutions are not asymptotically anti de Sitter, one can use the counterterm method in order to compute the conserved quantities of these solutions. Here, by reviewing the counterterm method for asymptotically anti de Sitter spac...

Stability of higher derivative modifications of Einstein - aether theory

A time-like unit vector field is used to generalize Einstein's gravity. The resulting theory, called the Einstein-aether theory, consists of a minimal coupling between an aether field and gravity. Inspired by the Bopp-Podolsky electrodynamics, which is well-known for removing the singularity at the point charge, we generalized the Einstein-aether theory by adding such a higher order self-intera...