  There have been long debates about the initial condition of inflationary
perturbations. In this work we explicitly show the decay of excited states
during inflation via interactions. For this purpose, we note that the folded
shape non-Gaussianity can be interpreted as the decay of the non-Bunch-Davies
initial condition. The one loop diagrams with non-Bunch-Davies propagators are
calculated to uncover the decay of such excited states. The observed smallness
of non-Gaussianity keeps the window open for probing inflationary initial
conditions and trans-Planckian physics.
