Observational constraints on quantum decoherence during inflation

Understand

Since inflationary perturbations must generically couple to all degrees of freedom present in the early Universe, it is more realistic to view these fluctuations as an open quantum system interacting with an environment.

• Then, on very general grounds, their evolution can be modelled with a Lindblad equation.
• This modified evolution leads to quantum decoherence of the system, as well as to corrections to observables such as the power spectrum of curvature fluctuations.
• On one hand, current cosmological observations constrain the properties of possible environments and place upper bounds on the interaction strengths.