English

Large non-Gaussianity from two-component hybrid inflation

Astrophysics 2010-04-30 v2 General Relativity and Quantum Cosmology High Energy Physics - Theory

Abstract

We study the generation of non-Gaussianity in models of hybrid inflation with two inflaton fields, (2-brid inflation). We analyse the region in the parameter and the initial condition space where a large non-Gaussianity may be generated during slow-roll inflation which is generally characterised by a large f_NL, tau_NL and a small g_NL. For certain parameter values we can satisfy tau_NL>>f_NL^2. The bispectrum is of the local type but may have a significant scale dependence. We show that the loop corrections to the power spectrum and bispectrum are suppressed during inflation, if one assume that the fields follow a classical background trajectory. We also include the effect of the waterfall field, which can lead to a significant change in the observables after the waterfall field is destabilised, depending on the couplings between the waterfall and inflaton fields.

Keywords

Cite

@article{arxiv.0812.0807,
  title  = {Large non-Gaussianity from two-component hybrid inflation},
  author = {Christian T. Byrnes and Ki-Young Choi and Lisa M. H. Hall},
  journal= {arXiv preprint arXiv:0812.0807},
  year   = {2010}
}

Comments

16 pages, 6 figures; v2: comments and references added, typos corrected, matches published version

R2 v1 2026-06-21T11:48:06.217Z