Matter power spectrum in f(R) gravity with massive neutrinos

TL;DR

This paper investigates how massive neutrinos influence the matter power spectrum in f(R) gravity, showing that neutrino free streaming can offset scalaron-induced growth, allowing models with observable deviations in dark energy to align with clustering data.

Contribution

It demonstrates that neutrino free streaming can counteract scalaron effects in f(R) gravity, reconciling deviations in dark energy parameters with matter clustering observations.

Findings

Neutrino free streaming offsets scalaron-driven growth on small scales.

Models with $w_\DE$ deviating from -1 can match observations if neutrino mass is around 0.5 eV.

Massive neutrinos can reconcile f(R) gravity models with matter power spectrum data.

Abstract

The effect of massive neutrinos on matter power spectrum is discussed in the context of $f(R)$ gravity. It is shown that the anomalous growth of density fluctuations on small scales due to the scalaron force can be compensated by free streaming of neutrinos. As a result, models which predict observable deviation of the equation-of-state parameter $w_\DE$ from $w_\DE=-1$ can be reconciled with observations of matter clustering if the total neutrino mass is $O(0.5 \eV)$.