Dark matter-neutrino interactions through the lens of their cosmological implications

TL;DR

This paper explores potential particle physics models where dark matter interacts with active neutrinos, analyzing their cosmological effects and constraining the interaction parameters through astrophysical data.

Contribution

It systematically identifies all renormalizable models coupling dark matter to neutrinos and assesses their cosmological and astrophysical signatures to constrain parameter space.

Findings

Dark matter-neutrino interactions affect structure formation.

Large couplings are excluded by astrophysical observations.

Masses up to a few MeV for dark matter are ruled out.

Abstract

Dark matter and neutrinos provide the two most compelling pieces of evidence for new physics beyond the Standard Model of Particle Physics but they are often treated as two different sectors. The aim of this paper is to determine whether there are viable particle physics frameworks in which dark matter can be coupled to active neutrinos. We use a simplified model approach to determine all possible renormalizable scenarios where there is such a coupling, and study their astrophysical and cosmological signatures. We find that dark matter-neutrino interactions have an impact on structure formation and lead to indirect detection signatures when the coupling between dark matter and neutrinos is sufficiently large. This can be used to exclude a large fraction of the parameter space. In most cases, dark matter masses up to a few MeV and mediator masses up to a few GeV are ruled out. The exclusion region can be further extended when dark matter is coupled to a spin-1 mediator or when the dark matter particle and the mediator are degenerate in mass if the mediator is a spin-0 or spin-1/2 particle.