title: Open quantum system approach to the Gibbons-Hawking effect of de Sitter space-time.
abstract: We analyze, in the paradigm of open quantum systems, the reduced dynamics of a freely falling two-level detector in de Sitter space-time in weak interaction with a reservoir of fluctuating quantized conformal scalar fields in the de Sitter-invariant vacuum. We find that the detector is asymptotically driven to a thermal state at the Gibbons-Hawking temperature, regardless of its initial state. Our discussion, therefore, shows that the Gibbons-Hawking effect of de Sitter space-time can be understood as a manifestation of thermalization phenomena that involves decoherence and dissipation in open quantum systems.
authors.affiliation: Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Yu