On the observability of coupled dark energy with cosmic voids

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 ΛCDM 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.

Using cosmic voids to distinguishf(R) gravity in future galaxy surveys

“…Previous works have shown the susceptibility of these properties to changes in gravity (e.g. Bos et al 2012;Sutter et al 2015b). This work focuses on the observational relevancy of each property, so we will present the analysis with emphasis on the strengths and weaknesses each property displays.…”

“…These underdense regions, commonly referred to as voids, could then provide a means of distinguishing between CDM cosmology and modified gravity models. Already these voids have been used as a potential diagnostic for examining coupled DE-DM models (Sutter et al 2015b), and have been used in applications such as weak antilensing (Clampitt & Jain 2014;Melchior et al 2014), the Alcock-Paczynski test (Lavaux & Wandelt 2012;Sutter et al 2012bSutter et al , 2014c, and the integrated Sachs-Wolfe effect (Ilić, Langer & Douspis 2013;Planck Collaboration XIX 2014b), demonstrating the usefulness of voids as cosmological probes. With regard to modified gravity and voids, some efforts have been made already to explore this avenue (Li, Zhao & Koyama 2012;Clampitt, Cai & Li 2013), and initial results provide hints that voids may indeed be a viable testbed.…”

Testing gravity using cosmic voids

“…For example, the Alcock-Paczynski test using stacking of voids has been demonstrated to be a powerful probe of distance distortions between the line of sight and transverse directions (Lavaux & Wandelt 2012;Sutter et al 2014a); stacking of voids for the cosmic microwave background has been used as an alternative to the cross-correlation method to detect the integrated Sachs-Wolfe effect (Granett, Neyrinck & Szapudi 2008;Cai et al 2013Cai et al , 2014Ilić, Langer & Douspis 2013;Planck Collaboration XIX 2014;Hotchkiss et al 2015); the weak gravitational lensing effect of voids, as an analogue to that of haloes, has been shown to be capable of measuring the matter density profiles of voids (Clampitt & Jain 2014;Melchior et al 2014); void ellipticity has been shown to be sensitive to the dark energy equation of state (Bos et al 2012); void properties have been studied in dynamical dark energy (Bos et al 2012), coupled dark energy (Li 2011;Sutter et al 2015) and modified gravity (Li, Zhao & Koyama 2012b) models using N-body simulations.…”

Counting voids to probe dark energy

“…Alcock-Paczyński test on void stacks [7,8,18,28], tests of coupled dark energydark matter models [29], tests of modified gravity models [30][31][32], constraints from CMB lensing with cosmic voids [33]. To understand the potential of void-based cosmology with Euclid and WFIRST requires realistic estimates of void abundances based on updated details on both missions, such as those we present in this paper.…”