# New constraints on the linear growth rate using cosmic voids in the SDSS DR12 datasets

## TL;DR

This paper measures the cosmic structure growth rate around voids in SDSS DR12 data, finding results consistent with the standard cosmological model and demonstrating the effectiveness of void-based analyses for cosmological constraints.

## Contribution

It introduces a simple multipole analysis of voids to accurately measure the growth rate, confirming its consistency with bcDM and showing its potential as a complementary method.

## Key findings

- Measured bc parameter: bc=0.33b10.06 (LOWZ) and bc=0.36b10.05 (CMASS)
- Results are consistent with bcCDM predictions
- Void-based redshift-space distortion analysis provides unbiased growth rate constraints.

## Abstract

We present a new analysis of the inferred growth rate of cosmic structure measured around voids, using the LOWZ and the CMASS samples in the twelfth data release (DR12) of SDSS. Using a simple multipole analysis we recover a value consistent with $\Lambda$CDM for the inferred linear growth rate normalized by the linear bias: the $\beta$ parameter. This is true in both the mock catalogues and the data, where we find $\beta=0.33\pm0.06$ for the LOWZ sample and $\beta=0.36\pm0.05$ for the CMASS sample. This work demonstrates that we can expect redshift-space distortions around voids to provide unbiased and accurate constraints on the growth rate, complementary to galaxy clustering, using simple linear modelling.