Large Nonlocal Non-Gaussianity from a Curvaton Brane
  We use a generalized delta N formalism to study the generation of the
primordial curvature perturbation in the curvaton brane scenario inspired by
stringy compactifications. We note that the non-Gaussian features, especially
the trispectra, crucially depend on the decay mechanism in a general curvaton
scenario. Specifically, we study the bispectra and trispectra of the curvaton
brane model in detail to illustrate the importance of curvaton decay in
generating nonlinear fluctuations. When the curvaton brane moves
nonrelativistically during inflation, the shape of non-Gaussianity is local,
but the corresponding size is different from that in the standard curvaton
scenario. When the curvaton brane moves relativistically in inflationary stage,
the shape of non-Gaussianity is of equilateral type.
