Thermodynamic Properties Of The Thermal-like Equilibrium Universe

In this paper,we study the thermodynamic properties of the thermal-likeequilibrium(TE)universe with the apparent horizon as the boundary.This paper mainly includes the four parts.In the first part,the constitution and evolution properties of the TE universe are briefly introduced.In the second part,the composition of the TE universe and the scalar field description for the TE universe are introduced.In the third part,we study the second law of thermodynamics and the generalized second law of thermodynamics of the TE universe.We obtain the conditions from the second law of thermodynamics and the second law of thermodynamics for the TE universe.For a class of TE universe,the fluid entropy,total entropy,total entropy change rate and the production rate of the fluid entropy are calculated.The results show that the fluid in TE universe does not satisfy the Euler relationship since it is negative.In the fourth part,we show the energy ofthe TE universe in the f(R)gravity.