2020-07-13

UTAPwiki/セミナー/初期宇宙・相対論速報

Thermodynamical interpretation for the second law of Cosmology †

Ido Ben-Dayan †

The area of a future holographic screen increases monotonically. Associating this area with entropy results in a generalized second law for Cosmology (GSLC). Unlike black hole horizons, screens relevant to Cosmology have no thermodynamical interpretation.
Past efforts have tried to express thermodynamical quantities related to gravity in terms of phase space variables and microstates. Such phase space constructions of black holes and accelerated observers have been carried out. We will utilize this notion for holographic screens.
Relating the entropy of the screens to spacetime degrees of freedom surface density derived from a phase space enables us to identify the entropy of any holographic screen as the entropy detected by accelerating observers due to their acceleration. Using Unruh's temperature and the equivalence principle, this gives the holographic screens' temperature and yields a thermodynamical interpretation of the GSLC.