Thermodynamical properties of dark energy

Abstract

We have investigated the thermodynamical properties of dark energy. Assuming that the dark energy temperature $T\sim a^{-n}$ and considering that the volume of the Universe enveloped by the apparent horizon relates to the temperature, we have derived the dark energy entropy. For dark energy with constant equation of state $w>-1$ and the generalized Chaplygin gas, the derived entropy can be positive and satisfy the entropy bound. The total entropy, including those of dark energy, the thermal radiation and the apparent horizon, satisfies the generalized second law of thermodynamics. However, for the phantom with constant equation of state, the positivity of entropy, the entropy bound, and the generalized second law cannot be satisfied simultaneously.

5 two column pages, 2 figures; v2: discussion on thermal equilibrium with the horizon is added, v3: minor corrections, published in PRD

References in corpus (6)

• Dynamics of dark energy
• Friedmann Equations of FRW Universe in Scalar-tensor Gravity, f(R) Gravity and First Law of Thermodynamics
• Thermodynamic route to Field equations in Lanczos-Lovelock Gravity
• Generalized Second Law of Thermodynamics in Quintom Dominated Universe
• The Holographic Model of Dark Energy and Thermodynamics of Non-Flat Accelerated Expanding Universe
• Schwarzschild black hole and the generalized second law in phantom-dominated universe

Cited by in corpus (13)

• Friedmann Equations and Thermodynamics of Apparent Horizons
• Thermodynamics and classification of cosmological models in the Horava-Lifshitz theory of gravity
• Cosmological apparent and trapping horizons
• Generalized second law in modified theory of gravity
• The generalized second law of gravitational thermodynamics on the apparent and event horizons in FRW cosmology
• Viscous dissipative Chaplygin gas dominated homogenous and isotropic cosmological models
• The Coincidence Problem and Interacting Holographic Dark Energy
• Thermodynamics of k-essence
• Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
• On thermodynamics second law in the modified Gauss Bonnet gravity
• Quantum cosmic models and thermodynamics
• Holographic dark energy: quantum correlations against thermodynamical description
• The Unified First law in "Cosmic Triad" Vector Field Scenario