Conditions for observable bi and tri-spectra in two-field slow-roll
  inflation
  We find constraints on inflationary dynamics that yield a large local
bispectrum and/or trispectrum during two-field slow-roll inflation. This leads
to simple relations between the non-Gaussianity parameters, simplifying the
Suyama-Yamaguchi inequality and also producing a new result between the
trispectrum parameters tNL and gNL.
