Oscillating nonlinear large scale structure in growing neutrino quintessence

TL;DR

This paper presents the first N-body simulations of nonlinear structure growth in Growing Neutrino cosmologies, revealing pulsating neutrino density contrasts and potential observational signatures like enhanced bulk flows.

Contribution

It introduces the first nonlinear simulations of neutrino and dark matter structure formation in Growing Neutrino models, including statistical analysis of neutrino lumps over redshift.

Findings

Neutrino density contrast exhibits pulsation over time.

Neutrino lumps' mass distribution characterized at various redshifts.

Potential observational signatures include enhanced bulk flows.

Abstract

Growing Neutrino quintessence describes a form of dynamical dark energy that could explain why dark energy dominates the universe only in recent cosmological times. This scenario predicts the formation of large scale neutrino lumps which could allow for observational tests. We perform for the first time N-body simulations of the nonlinear growth of structures for cold dark matter and neutrino fluids in the context of Growing Neutrino cosmologies. Our analysis shows a pulsation - increase and subsequent decrease - of the neutrino density contrast. This could lead to interesting observational signatures, as an enhanced bulk flow in a situation where the dark matter density contrast only differs very mildly from the standard LCDM scenario. We also determine for the first time the statistical distribution of neutrino lumps as a function of mass at different redshifts. Such determination provides an essential ingredient for a realistic estimate of the observational signatures of Growing Neutrino cosmologies. Due to a breakdown of the non-relativistic Newtonian approximation our results are limited to redshifts z > 1.