Constraints on neutrino -- dark matter interactions from cosmic microwave background and large scale structure data

TL;DR

This paper investigates how non-standard neutrino-dark matter interactions affect cosmic microwave background and large scale structure, providing updated constraints on the interaction strength and dark matter fraction.

Contribution

It introduces a parameterization of neutrino-dark matter interactions and derives new cosmological constraints using combined CMB and large scale structure data.

Findings

Constraints on the fraction of interacting dark matter

Limits on the neutrino-dark matter scattering cross section

Implications for dark matter models with neutrino interactions

Abstract

We update a previous investigation of cosmological effects of a non-standard interaction between neutrinos and dark matter. Parameterizing the elastic-scattering cross section between the two species as a function of the temperature of the universe, the resulting neutrino-dark matter fluid has a non-zero pressure, which determines diffusion-damped oscillations in the matter power spectrum similar to the acoustic oscillations generated by the photon-baryon fluid. Using cosmic microwave background data in combination with large scale structure experiment results, we then put constraints on the fraction of the interacting dark matter component as well as on the corresponding opacity.