Non-gaussianity from the trispectrum and vector field perturbations

TL;DR

This paper investigates the non-Gaussian features of primordial curvature perturbations generated by vector fields, focusing on the trispectrum and its relation to bispectrum and anisotropy, using the elta N formalism.

Contribution

It provides a novel analysis of the trispectrum from vector field perturbations, establishing consistency relations with bispectrum and anisotropy levels, and compares predictions with observational bounds.

Findings

Derived the order of magnitude of ta_{NL} in this scenario.

Established consistency relations between ta_{NL}, f_{NL}, and g_.

Compared theoretical predictions with WMAP observational bounds.

Abstract

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.