Spinodal Solution to Swampland Inflationary Constraints

We show how the inclusion of non-perturbative, dynamical quantum effects on the evolution of the inflaton can allow for an inflationary phase that is both consistent with cosmological constraints and avoids the problems associated with the so-called swampland conditions. In particular, for concave potentials such as those preferred by the Planck data, spinodal instabilities associated with tachyonic masses for long wavelength modes induce a second round of inflation, which in essence decouples the tree-level potential from the inflationary phase. We illustrate these points using natural inflation as an example.