Note on decoherence of the cosmological background by thermal perturbations in the language of open quantum systems
This study investigates how thermal cosmological perturbations act as an environment to cause decoherence in a semiclassical inflationary universe using open quantum systems theory. By incorporating environmental backreaction instead of simple tracing, the authors derive a master equation. They find that this thermal decoherence timescale can be shorter than the Hubble time, suggesting that thermal effects significantly suppress quantum coherence on relevant cosmological scales.