Signature of Massive Neutrinos from the Clustering of Critical Points. I. Density-threshold-based Analysis in Configuration Space

Abstract

Critical points represent a subset of special points tracing cosmological structures, carrying remarkable topological properties. They thus offer a richer high-level description of the multiscale cosmic web, being more robust to systematic effects. For the first time, we characterize here their clustering statistics in massive neutrino cosmologies, including cross-correlations, and quantify their simultaneous imprints on the corresponding web constituents - i.e., halos, filaments, walls, and voids - for a series of rarity levels. Our first analysis is centered on a density-threshold-based approach in configuration space. In particular, we show that the presence of massive neutrinos does affect the baryon acoustic oscillation peak amplitudes of all of the critical point correlation functions above/below the rarity threshold, as well as the positions of their correspondent inflection points at large scales: departures from analogous measurements carried out in the baseline massless neutrino scenario can reach up to ~7% in autocorrelations and ~9% in cross-correlations at z=0 when M_nu=0.1 eV, and are more pronounced for higher neutrino mass values. In turn, these combined multiscale effects can be used as a novel technique to set upper limits on the summed neutrino mass and infer the type of hierarchy. Our study is particularly relevant for ongoing and future large-volume redshift surveys such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, which will provide unique datasets suitable for establishing competitive neutrino mass constraints.