Islands and the de Sitter entropy bound

Abstract

The de Sitter (dS) entropy bound gives the maximal number of e-folds that non-eternal inflation can last before violating the thermodynamical interpretation of dS space. This semiclassical argument is the analogue, for dS space, of the Black-Hole information paradox. We use techniques developed to address the latter, namely the island formula, to calculate semiclassically the fine-grained entropy as seen by a Minkowskian observer after inflation and find that this follows a Page-like curve, never exceeding the thermodynamic dS entropy. This calculation, performed for a CFT in 2D gravity, suggests that the semiclassical expectation should be modified in such a way that the entropy bound might actually not be present.

16 pages, 7 figures. References added

References in corpus (8)

• A Measure of de Sitter Entropy and Eternal Inflation
• Islands in cosmology
• The central dogma and cosmological horizons
• The Price of Curiosity: Information Recovery in de Sitter Space
• The Volume of the Universe after Inflation and de Sitter Entropy
• No Page Curves for the de Sitter Horizon
• Islands in Multiverse Models
• The Multiverse in an Inverted Island

Cited by in corpus (2)

• Defect extremal surfaces for entanglement negativity
• Implication of island for inflation and primordial perturbations