Generalized Second Law of Thermodynamics in Extended Theories of Gravity

Abstract

By employing the general expression of temperature $T_h=|\hat{I}º|/2\ddot{I}€=\frac{1}{2\ddot{I}€{\tilde{r}}_A}(1-\frac{{\dot{\tilde{r}}}_A}{2H{\tilde{r}}_A})$ associated with the apparent horizon of a FRW universe and assuming a region of FRW universe enclosed by the apparent horizon as a thermal system in equilibrium, we are able to show that the generalized second law of thermodynamics holds in Gauss-Bonnet gravity and in more general Lovelock gravity.

10 pages