In the present work we found the geodesic structure of an AdS black hole. By means of a detailed analyze of the corresponding effective potentials for particles and photon, we found all the possible motions which are allowed by the energy levels. Radial and non radial trajectories were exactly evaluated for both geodesics. The founded orbits were plotted in order to have a direct visualization of the allowed motions. We show that the geodesic structure of this black hole presents new type of motions not allowed by the Schwarzschild spacetime.

This paper studies the stability of warm inflationary solutions when the viscous pressure is taken into account. The latter is a very natural and physically motivated ingredient of warm inflation and is seen to widen the stability range of warm inflation. The spectral index parameters, n s , n T , and their ratio are derived. The corresponding WMAP7 data are used to fix some parameters of the model. Two specific examples are discussed in detail: (i) a potential given by V (φ, T ) = v 1 (φ) + v 2 (T ), and (ii) a potential of the form V (φ, T ) = α v 1 (φ) v 2 (T ). In both cases, the viscosity has little impact on the said ratio.

In this paper we study the geodesic structure of the Schwarzschild black hole in rainbow gravity analyzing the behavior of null and time-like geodesic. We find that the structure of the geodesics essentially does not change when the semiclassical effects are included. However, we can distinguish different scenarios if we take into account the effects of rainbow gravity. Depending on the type of rainbow functions under consideration, inertial and external observers see very different situations in radial and non-radial motion of a test particle.

In this work we address the study of movement of charged particles in the background of charged black holes with non-trivial asymptotic behavior. We compute the exact trajectories for massivecharged particles in terms of elliptic Jacobi functions. Finally we obtain a detailed description of orbits for Reissner-Nordström (Anti) de Sitter black holes in terms of charge, mass and energy of the particles.