The Study Of The Thermodynamical Aspects Of AdS Black Holes

In this dissertation,we investigate some thermodynamical properties of black holes in AdS spactime,including the universal property of entropy relations of multi-horizon AdS black holes and the effects of dark energy on the efficiency of black hole as heat engine.At first,we investigate the angular momentum independence of the entropy sum and product for AdS rotating black holes based on the first law of thermodynamics and a mathematical lemma related to Vandermonde determinant.We find that the entropy sum is always independent of angular momentum for all dimensions.For entropy prod-uct,if the dimension of black holes d>4 and with at least one rotation parameter a_i=0,the entropy product is independent of angular momentum,while the mass-free of en-tropy sum and entropy product for rotating black holes only stand for higher dimensions(d>4)and for all dimensions,respectively.On the other hand,we find that the intro-duction of a negative cosmological constant will not affect the angular momentum-free of entropy sum and product but the criterion for angular momentum-independence of entropy product will be affected.And then,we generalize our discussion in chapter 2 into the charged black holes case which is not studied in chapter two.We investigate the angular momentum inde-pendence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions.We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes,the entropy sum of the black holes is independent of angular momentum in dimensions d?4,while the independence of angular momentum of the entropy product holds if the black holes possess at least one zero rotation parameter a _j=0 in higher dimen-sions d?5,which means that the cosmological constant does not affect the angular-momentum independence of entropy sum and entropy product provided that charge?=0.In asymptotically flat spactime,we find that the charge will not affect the angu-lar momentum-independence of entropy relations.At last,we introduce some research works on the thought about regarding the AdS black holes as heat engine to extract energy from black holes and the thermodynamics of AdS black holes surrounded by dark energy.Based on the thermodynamics we have introduced,we investigate the efficiency of RN-AdS black holes under the existence of Quintessence and find that Quintessence field can boost the efficiency of RN-AdS black holes.