The effects of massive neutrinos on the linear point of the correlation function

TL;DR

This paper investigates whether the linear point (LP) in the correlation function remains a reliable standard ruler in cosmologies with massive neutrinos and explores its potential to constrain neutrino masses.

Contribution

The study extends previous analyses of the LP to massive-neutrino cosmologies using N-body simulations, demonstrating its robustness as a standard ruler despite neutrino-induced scale-dependent growth.

Findings

LP remains a reliable standard ruler with massive neutrinos.

The shift in LP position can help constrain neutrino masses.

The method is effective in the BAO scale range.

Abstract

The linear point (LP), defined as the mid-point between the dip and the peak of the two-point clustering correlation function (TPCF), has been shown to be an excellent standard ruler for cosmology. In fact, it is nearly redshift-independent, being weakly sensitive to non-linearities, scale-dependent halo bias and redshift-space distortions. So far, these findings were tested assuming that neutrinos are massless; in this paper we extend the analysis to massive-neutrino cosmologies. In particular, we examine if the scale-dependent growth induced by neutrinos affects the LP position and if it is possible to detect the neutrino masses using the shift of the LP compared to the massless-neutrino case. For our purposes, we employ two sets of state-of-the-art $N$-body simulations with massive neutrinos. For each of them we measure the TPCF of cold dark matter (CDM) and halos and, to estimate the LP, fit the TPCF with a model-independent parametric fit in the range of scales of the Baryon Acoustic Oscillations (BAO). Overall, we find that the LP retains its features as a standard ruler even when neutrinos are massive. The cosmic distances measured with the LP can therefore be employed to constrain the neutrino mass.