Massive Neutrinos Leave Fingerprints on Cosmic Voids

TL;DR

This study demonstrates that cosmic void statistics contain unique information about neutrino masses beyond traditional methods, showing how neutrinos influence void properties and clustering in simulations, which can aid future cosmological constraints.

Contribution

It reveals the impact of massive neutrinos on cosmic voids and their clustering, highlighting the potential of void statistics to improve neutrino mass measurements in cosmology.

Findings

Neutrino mass affects the number and size of voids depending on tracer type.

Void clustering scale is sensitive to neutrino mass and tracer bias.

Void signatures can help break degeneracies in cosmological parameters.

Abstract

Do void statistics contain information beyond the tracer 2-point correlation function? Yes! As we vary the sum of the neutrino masses, we find void statistics contain information absent when using just tracer 2-point statistics. Massive neutrinos uniquely affect cosmic voids. We explore their impact on void clustering using both the DEMNUni and MassiveNuS simulations. For voids, neutrino effects depend on the observed void tracers. As the neutrino mass increases, the number of small voids traced by cold dark matter particles increases and the number of large voids decreases. Surprisingly, when massive, highly biased, halos are used as tracers, we find the opposite effect. The scale at which voids cluster, as well as the void correlation, is similarly sensitive to the sum of neutrino masses and the tracers. This scale dependent trend is not due to simulation volume or halo density. The interplay of these signatures in the void abundance and clustering leaves a distinct fingerprint that could be detected with observations and potentially help break degeneracies between different cosmological parameters. This paper paves the way to exploit cosmic voids in future surveys to constrain the mass of neutrinos.