Three-form inflation and non-Gaussianity
Abstract
We calculate the perturbed action, at second and third order, for a massive three-form field minimally coupled to gravity, and use it to explore the observational predictions of three-form inflation. One intriguing result is that the value of the spectral index is nearly independent of the three-form potential, being fixed solely by the number of e-folds of inflation, with n_s=0.97 for the canonical number of 60. Considering the bispectrum, we employ standard techniques to give explicit results for two models, one of which produces a large non-Gaussianity. Finally, we confirm our results by employing a duality relating the three-form theory to a non-canonical scalar field theory and explicitly re-computing results in this dual picture.
Cite
@article{arxiv.1209.2156,
title = {Three-form inflation and non-Gaussianity},
author = {David J. Mulryne and Johannes Noller and Nelson J. Nunes},
journal= {arXiv preprint arXiv:1209.2156},
year = {2014}
}
Comments
23 pages, 6 figures. Typos corrected and addition of one appendix. Accepted in JCAP