Constraining fast-roll inflation
  We present constraints on how far single field inflation may depart from the
familiar slow-roll paradigm. Considering a fast-roll regime while requiring a
(near)-scale-invariant power spectrum introduces large self-interactions for
the field and consequently large and scale-dependent non-Gaussianities.
Employing this signal, we use the requirement of weak-coupling together with
WMAP constraints to derive bounds on generic $P(X,\phi)$ theories of single
field inflation.
