“…In fact, there have been several attempts to do precisely that [26,27,30,31,47]. In addition, a lot of work has been invested into a much easier set of problems, namely into studying how the inflaton coupling with the other quantum fields (scalar, fermionic or vector) induces decoherence in the inflaton sector [16,18,31,34]. While the earlier works considered simple models with bilinear couplings [16,18] (since these couplings are non-dissipative, they are not true interactions), more recent works studied true interactions [31,34].…”