Event Details

Cosmology group seminar: Evaporation of de Sitter space

Abstract: The exponentially expanding de Sitter solution is frequently encountered in cosmology due to its significance for the late and early Universe. However, its stability in a quantised theory has for a long time been the source of debate. In this talk we discuss this issue in the framework of semi-classical gravity. Based on a first principle calculation, I argue that when one considers the experiences of a local observer, the quantum back reaction destabilizes de Sitter space leading to a gradual continuous increase of the dS horizon. This implies that the cosmological 'constant' decays over time, with flat space as the asymptotic late time solution.