Accelerated Expansion of the Universe based on Emergence of Space and Thermodynamics of the Horizon

Abstract

Researches in the several decades have shown that the dynamics of gravity is closely related to thermodynamics of the horizon. In this paper, we derive the Friedmann acceleration equation based on the idea of "emergence of space" and thermodynamics of the Hubble horizon whose temperature is obtained from the unified first law of thermodynamics. Then we derive another evolution equation of the universe based on the energy balance relation $\rho V_{H}=TS$. Combining the two evolution equations and the equation of state of the cosmic matter, we obtain the evolution solutions of the FRW universe. We find that the solutions obtained by us include the solutions obtained in the standard general relativity(GR) theory. Therefore, it is more general to describe the evolution of the universe in the thermodynamic way.