Decoherence of gauge-invariant metric fluctuations during inflation - art.no. 043507

I studied the gauge-invariant fluctuations of the metric during inflation. In the infrared sector the metric fluctuations can be represented by a coar se-grained field. I can write a Schrodinger equation for the coarse-grained metric fluctuations which is related to an effective Hamiltonian for a tim e dependent parameter of mass harmonic oscillator with a stochastic externa l force. I also studied the wave function for a power-law expanding univers e. I find that the phase space of the quantum state for super Hubble scalar metric perturbations loses its coherence at the end of inflation. This eff ect is a consequence of interference between the super Hubble metric pertur bations and its canonical conjugate variable, which is produced by the inte raction of the coarse-grained scalar metric fluctuation with the environmen t.