Consistency relation and inflaton field redefinition in the delta N
  formalism
  We compute for general single-field inflation the intrinsic non-Gaussianity
due to the self-interactions of the inflaton field in the squeezed limit. We
recover the consistency relation in the context of the delta N formalism, and
argue that there is a particular field redefinition that makes the intrinsic
non-Gaussianity vanishing, thus improving the estimate of the local
non-Gaussianity using the delta N formalism.
