The Thermodynamics Of (A)dS Black Holes

Although the investigation about the thermodynamics of black holes has been developed in recent years, its characteristic has not been understood explicitly, especially for the essence and origin of the black hole entropy. In this thesis we focus our attentions on the thermodynamics of (Anti-)de Sitter Schwarzschild black holes.This thesis contains four chapters. In the first chapter after presenting a brief introduction to the basic notion and properties of black holes, we review four thermodynamics laws of black holes and the quantum nature of its entropy.The second chapter we investigate the thermodynamics of modified (Anti-)de Sitter Schwarzschild black holes in the framework of rainbow gravity with a cosmological constant. First of all, we introduce the properties of doubly special relativity (DSR) and rainbow gravity. Then starting from the modified Einstein equations, we obtain a sort of modified (Anti-)de Sitter Schwarzschild black hole solutions. Its thermodynamic properties are investigated. In general the temperature of modified black holes is dependent on the energy of probes which take the measurement. However, a notion of intrinsic temperature can be introduced by identifying these probes with radiation particles emitted from black holes. Given a specific modified dispersion relation, the corresponding temperature of black holes is derived. It is interesting to find that the Hawking temperature of this sort of black holes can be reproduced by employing the extended uncertainty principle and modified dispersion relations to the (Anti-)de Sitter Schwarzschild black holes.In chapter three we study the entropy of Anti-de Sitter black holes using the method of the minimum increase of area based on Bekenstein entropy assumption. Firstly we describe the modified dispersion relations(MDR) and the generalized uncertainty principle(GUP) and investigate their impacts on black holes. Then with the help of Bekenstein entropy assumption we discuss the impacts of the modification of dispersion relations on the black hole entropy. In this chapter we introduce two kinds of modified dispersion relations and study their impacts on the entropy of AdS black holes. It turns out that the one with linear correction term of the Planck energy leads to a A^1/2 contribution to black holes entropy, which the other one which contains a term proportional to the square of Planck energy predicts the entropy with a leading correction term of log-area type, agreeing with the results derived in quantum gravity theories.We make a summary and give some outlooks in chapter four.