Cosmological hydrodynamical simulations of clustering dark energy with Nefertiti

TL;DR

This paper introduces the first cosmological hydrodynamical simulations of clustering dark energy using Nefertiti, revealing significant nonlinear dark energy fluctuations that impact structure formation and could inform observational constraints.

Contribution

It presents the first consistent nonlinear clustering dark energy simulations with Nefertiti, showing stable fluctuations and their effects on large-scale structure.

Findings

Dark energy perturbations become nonlinear on small scales.

Clustering dark energy contributes ~10% to total density perturbations.

Simulations suggest potential for constraining dark energy properties from data.

Abstract

We present the first cosmological simulations that consistently include nonlinear clustering dark energy evolved as a fluid with the numerical hydrodynamics code Nefertiti. Dark energy perturbations become fully nonlinear on small scales, developing significant density fluctuations without exhibiting the catastrophic instabilities previously reported. We show results for the density distribution, power spectrum, and halo profiles of dark energy. Clustering dark energy contributes to the total density perturbation at the $\sim 10\%$ level inside and around massive halos in our simulations with constant $w=-0.9$, a significant potential signal for lensing and dynamical probes. These simulations pave the way to robust constraints on the speed of sound of dark energy perturbations from large-scale structure data.