English

Non-Gaussian tails without stochastic inflation

Cosmology and Nongalactic Astrophysics 2024-11-12 v2 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

We show, both analytically and numerically, that non-Gaussian tails in the probability density function of curvature perturbations arise in ultra-slow-roll inflation from the δN\delta N formalism, without invoking stochastic inflation. Previously reported discrepancies between both approaches are a consequence of not correctly accounting for momentum perturbations. Once they are taken into account, both approaches agree to an excellent degree. The shape of the tail depends strongly on the phase space of inflation.

Keywords

Cite

@article{arxiv.2406.02417,
  title  = {Non-Gaussian tails without stochastic inflation},
  author = {Guillermo Ballesteros and Thomas Konstandin and Alejandro Pérez Rodríguez and Mathias Pierre and Julián Rey},
  journal= {arXiv preprint arXiv:2406.02417},
  year   = {2024}
}

Comments

26 pages, 5 figures; v2 matches published version in JCAP

R2 v1 2026-06-28T16:53:07.238Z