On the observability of coupled dark energy with cosmic voids

TL;DR

This study uses N-body simulations and void analysis to explore how coupled dark energy models differ from standard cosmology, finding larger voids and altered density profiles that could be detectable with current data.

Contribution

It demonstrates that coupled dark energy influences void sizes and density profiles, providing potential observational signatures distinguishable from bcdm.

Findings

Coupled dark energy produces significantly larger voids.

Coupling results in broader, shallower density profiles.

Differences are potentially measurable with existing void catalogs.

Abstract

Taking N-body simulations with volumes and particle densities tuned to match the SDSS DR7 spectroscopic main sample, we assess the ability of current void catalogs (e.g., Sutter et al. 2012b) to distinguish a model of coupled dark matter-dark energy from {\Lambda}CDM cosmology using properties of cosmic voids. Identifying voids with the VIDE toolkit, we find no statistically significant differences in the ellipticities, but find that coupling produces a population of significantly larger voids, possibly explaining the recent result of Tavasoli et al. (2013). In addition, we use the universal density profile of Hamaus et al. (2014) to quantify the relationship between coupling and density profile shape, finding that the coupling produces broader, shallower, undercompensated profiles for large voids by thinning the walls between adjacent medium-scale voids. We find that these differences are potentially measurable with existing void catalogs once effects from survey geometries and peculiar velocities are taken into account.