Generalized second law in modified theory of gravity

In the context of modified theory of gravity (f(R) gravity) we try to study the conditions required for validity of the generalized second law.Comment: 9 pages, accepted for publication in Phys. Rev.

Generalized Noether symmetry in f(T) gravity

We consider modified teleparallel gravity, (f(T) gravity), as a framework to explain the present accelerated expansion of the universe. The matter component is assumed to be cold dark matter. To find the explicit form of the function $f$, we utilize generalized Noether theorem and use generalized vector fields as variational symmetries of the corresponding Lagrangian. We study the cosmological consequences of the obtained results.Comment: 14 pages, 3 figure

Temperature in warm inflation in non minimal kinetic coupling model

Warm inflation in the non minimal derivative coupling model with a general dissipation coefficient is considered. We investigate conditions for the existence of the slow roll approximation and study cosmological perturbations. The spectral index, and the power spectrum are calculated and the temperature of the universe at the end of the slow roll warm inflation is obtained.Comment: 18 pages, major revision, accepted by the European Physical Journal