Differential Neutrino Condensation onto Cosmic Structure

TL;DR

This paper introduces the differential neutrino condensation effect observed in simulations, which could enable new methods for measuring neutrino masses by analyzing galaxy properties in regions with varying neutrino densities.

Contribution

The discovery of the differential neutrino condensation effect in N-body simulations provides a novel approach to infer neutrino masses from cosmological data.

Findings

Neutrino masses influence galaxy properties in different regions.

The effect skews the halo mass function based on local neutrino abundance.

Potential for independent neutrino mass measurements in galaxy surveys.

Abstract

Astrophysical techniques have pioneered the discovery of neutrino mass properties. Current cosmological observations give an upper bound on neutrino masses by attempting to disentangle the small neutrino contribution from the sum of all matter using precise theoretical models. We discover the differential neutrino condensation effect in our TianNu N-body simulation. Neutrino masses can be inferred using this effect by comparing galaxy properties in regions of the universe with different neutrino relative abundance (i.e. the local neutrino to cold dark matter density ratio). In "neutrino-rich"' regions, more neutrinos can be captured by massive halos compared to "neutrino-poor" regions. This effect differentially skews the halo mass function and opens up the path to independent neutrino mass measurements in current or future galaxy surveys.