Baryonic Acoustic Oscillations (BAOs) studies based on the clustering of
voids and matter tracers provide important constraints on cosmological
parameters related to the expansion of the Universe. However, modelling the
void exclusion effect is an important challenge for fully exploiting the
potential of these kind of analyses. We thus develop two numerical methods to
describe the clustering of cosmic voids. Neither model requires additional
cosmological information beyond that assumed within the galaxy de-wiggled
model. The models consist in power spectra whose performance we assess in
comparison to a parabolic model on both Patchy boxes and light-cones. Moreover,
we test their robustness against systematic effects and the reconstruction
technique. The void model power spectra and the parabolic model with a fixed
parameter provide strongly correlated values for the Alcock-Paczynski
($\alpha $ ) parameter, for boxes and light-cones likewise. The resulting
$\alpha $ values - for all three models - are unbiased and their uncertainties
are correctly estimated. However, the numerical models show less variation with
the fitting range compared to the parabolic one. The Bayesian evidence suggests
that the numerical techniques are often favoured compared to the parabolic
model. Moreover, the void model power spectra computed on boxes can describe
the void clustering from light-cones as well as from boxes. The same void model
power spectra can be used for the study of pre- and post-reconstructed
data-sets. Lastly, the two numerical techniques are resilient against the
studied systematic effects. Consequently, using either of the two new void
models, one can more robustly measure cosmological parameters.

PREPRINT

# Cosmic void exclusion models and their impact on the distance scale measurements from large scale structure

Andrei Variu, Cheng Zhao, Daniel Forero-Sánchez, Chia-Hsun Chuang, Francisco-Shu Kitaura, Charling Tao, Amélie Tamone, Jean-Paul Kneib

Submitted on 8 November 2022

## Abstract

## Preprint

Comment: 18 pages, 24 figures

Subject: Astrophysics - Cosmology and Nongalactic Astrophysics