Rotating a Curvaton Brane in a Warped Throat
  In this paper we study a curvaton model obtained by considering a probe
anti-D3-brane with angular motion at the bottom of a KS throat with approximate
isometries. We calculate the spectrum of curvature perturbations and the
non-Gaussianities of this model. Specifically, we consider the limit of
relativistic rotation of the curvaton brane which leads to a small sound speed,
and thus it can be viewed as an implementation of the DBI-curvaton mechanism.
We find that the primordial power spectrum is nearly scale-invariant while the
non-Gaussianity of local type is sizable and that of equilateral type is
usually large and negative. Moreover, we study both the theoretical and
observational constraints on this model, and find that there exists a sizable
allowed region for the phase space of this model.
