Distinguishing f(R) gravity with cosmic voids

TL;DR

This paper investigates how properties of cosmic voids in galaxy surveys can be used to distinguish f(R) gravity models from standard bc CDM cosmology, showing that void sizes and counts are sensitive probes.

Contribution

It demonstrates that void abundance and size distributions in simulations can effectively differentiate f(R) gravity from bc CDM, providing forecasts for upcoming surveys.

Findings

Void sizes increase by up to 20% in f(R) models.

Void number function shifts significantly with f(R) coupling strength.

Forecasted constraint on b f_{R_0} is ^{-5}.

Abstract

We use properties of void populations identified in N-body simulations to forecast the ability of upcoming galaxy surveys to differentiate models of f(R) gravity from \Lambda CDM cosmology. We analyze simulations designed to mimic the densities, volumes, and clustering statistics of upcoming surveys, using the public VIDE toolkit. We examine void abundances as a basic probe at redshifts 1.0 and 0.4. We find that stronger f(R) coupling strengths produce voids up to ~20% larger in radius, leading to a significant shift in the void number function. As an initial estimate of the constraining power of voids, we use this change in the number function to forecast a constraint on the coupling strength of $\Delta f_{R_{0}} = 10^{-5}$.