Review of local non-Gaussianity from multi-field inflation
  We review models which generate a large non-Gaussianity of the local form. We
first briefly consider three models which generate the non-Gaussianity either
at or after the end of inflation; the curvaton scenario, modulated (p)reheating
and an inhomogeneous end of inflation. We then focus on ways of generating the
non-Gaussianity during inflation. We derive general conditions which a product
or sum separable potential must satisfy in order to generate a large local
bispectrum during slow-roll inflation. As an application we consider two-field
hybrid inflation. We then derive a formalism not based on slow roll which can
be applied to models in which the slow-roll parameters become large before
inflation ends. An exactly soluble two-field model is given in which this
happens. Finally we also consider further non-Gaussian observables; a scale
dependence of f_NL and the trispectrum.
