Cosmological Imprint of the Second Law of Thermodynamics

Abstract

We study the evolution of the universe in the presence of inflaton, matter, radiation, and holographic dark energy. The time evolution of the scale factor is obtained by solving the Friedmann equation of the universe with a good approximation. We present two independent ways which determine the value of the dark energy constant $d\sim 1$ from the observational data. The two ways are measuring the deceleration parameter and measuring a universal constant depending only on $d$. The universal constant is given by a dimensionless combination of three scale factors at the equipartition times of radiation-matter, radiation-dark energy, and matter-dark energy. We also discuss that the second law of thermodynamics determines the point of time when the dark energy dominated era begins in the universe.

18pages, 2 figures,

References in corpus (6)

• Constraints on Holographic Dark Energy from Latest Supernovae, Galaxy Clustering, and Cosmic Microwave Background Anisotropy Observations
• Friedmann Equations and Thermodynamics of Apparent Horizons
• Instability of holographic dark energy models
• Thermodynamical Interpretation of the Interacting Holographic Dark Energy Model in a non-flat Universe
• A covariant entropy conjecture on cosmological dynamical horizon
• The black hole dynamical horizon and generalized second law of thermodynamics