Non-gaussianity from the trispectrum and vector field perturbations

Understand

We use the \delta N formalism to study the trispectrum T_\zeta of the primordial curvature perturbation \zeta when the latter is generated by vector field perturbations, considering the tree-level and one-loop contributions.

• The order of magnitude of the level of non-gaussianity in the trispectrum, \tau_{NL}, is calculated in this scenario and related to the order of magnitude of the level of non-gaussianity in the bispectrum, f_{NL}, and the level of statistical anisotropy in the power spectrum, g_\zeta.
• Such consistency relations will put under test this scenario against future observations.
• Comparison with the expected observational bound on \tau_{NL} from WMAP, for generic inflationary models, is done.