Tachyon Mediated Non-Gaussianity

Understand

We describe a general scenario where primordial non-Gaussian curvature perturbations are generated in models with extra scalar fields.

• The extra scalars communicate to the inflaton sector mainly through the tachyonic (waterfall) field condensing at the end of hybrid inflation.
• These models can yield significant non-Gaussianity of the local shape, and both signs of the bispectrum can be obtained.
• These models have cosmic strings and a nearly flat power spectrum, which together have been recently shown to be a good fit to WMAP data.