Big Bang Nucleosynthesis in the presence of sterile neutrinos with altered dispersion relations

TL;DR

This paper explores how altered dispersion relations for sterile neutrinos can relax Big Bang Nucleosynthesis constraints, enabling compatibility with the early Universe's light element formation.

Contribution

It introduces a novel approach showing that modified dispersion relations can weaken BBN bounds on sterile neutrinos, allowing their existence without disrupting nucleosynthesis.

Findings

Altered dispersion relations can weaken BBN constraints on sterile neutrinos.

Sterile neutrinos with modified dispersion relations can coexist with successful nucleosynthesis.

The approach broadens the parameter space for sterile neutrino models.

Abstract

Big Bang Nucleosynthesis imposes stringent bounds on light sterile neutrinos mixing with the active flavors. Here we discuss how altered dispersion relations can weaken such bounds and allow compatibility of new sterile neutrino degrees of freedom with a successful generation of the light elements in the early Universe.