## Abstract

*Euclid*spectroscopic survey, which will include spectroscopic information for tens of millions of galaxies over 15000 deg

^{2}of the sky in the redshift range 0.9≤

*z*<1.8. We do this using simulated measurements obtained from the Flagship mock catalogue, the official

*Euclid*mock that closely matches the expected properties of the spectroscopic data set. To mitigate anisotropic selection-bias effects, we use a velocity field reconstruction method to remove large-scale redshift-space distortions from the galaxy field before void-finding. This allows us to accurately model contributions to the observed anisotropy of the cross-correlation function arising from galaxy velocities around voids as well as from the Alcock-Paczynski effect, and we study the dependence of constraints on the efficiency of reconstruction. We find that

*Euclid*voids will be able to constrain the ratio of the transverse comoving distance D

_{M}and Hubble distance D

_{H}to a relative precision of about 0.3%, and the growth rate fσ8 to a precision of between 5% and 8% in each of four redshift bins covering the full redshift range. In the standard cosmological model, this translates to a statistical uncertainty ΔΩ

_{m}=±0.0028 on the matter density parameter from voids, better than can be achieved from either

*Euclid*galaxy clustering and weak lensing individually. We also find that voids alone can measure the dark energy equation of state to 6% precision.

Original language | English |
---|---|

Article number | A78 |

Number of pages | 20 |

Journal | Astronomy and Astrophysics |

DOIs | |

Publication status | Published - 8 Sept 2023 |

## Keywords

- cosmology: observations
- cosmological parameters
- large-scale structure of Universe
- surveys
- UKRI
- STFC
- ST/T005009/2