A Comparison of Void-Finding Algorithms using Crossing Numbers

Fuente: arXiv
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Main Authors: Veyrat, Dahlia, Douglass, Kelly A., BenZvi, Segev
Format: Preprint
Published: 2023
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author Veyrat, Dahlia
Douglass, Kelly A.
BenZvi, Segev
author_facet Veyrat, Dahlia
Douglass, Kelly A.
BenZvi, Segev
contents We study how well void-finding algorithms identify cosmic void regions and whether we can quantitatively and qualitatively compare the voids they find with dynamical information from the underlying matter distribution. Using the ORIGAMI algorithm to determine the number of dimensions along which dark matter particles have undergone shell-crossing (crossing number) in N-body simulations from the AbacusSummit simulation suite, we identify dark matter particles that have undergone no shell crossing as belonging to voids. We then find voids in the corresponding halo distribution using two different void-finding algorithms: VoidFinder and Voronoi Voids (V2), a ZOBOV-based algorithm. The resulting void catalogs are compared to the distribution of dark matter particles to examine how their crossing numbers depend on void proximity. While both algorithms' voids have a similar distribution of crossing numbers near their centers, we find that beyond 0.25 times the effective void radius, voids found by VoidFinder exhibit a stronger preference for particles with low crossing numbers than those found by V2. We examine two possible methods of mitigating this difference in efficacy between the algorithms. While we are able to partially mitigate the ineffectiveness of V2 by using the distance from the void edge as a measure of centrality, we conclude that VoidFinder more reliably identifies dynamically distinct regions of low crossing number.
format Preprint
id arxiv_https___arxiv_org_abs_2302_05469
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A Comparison of Void-Finding Algorithms using Crossing Numbers
Veyrat, Dahlia
Douglass, Kelly A.
BenZvi, Segev
Cosmology and Nongalactic Astrophysics
We study how well void-finding algorithms identify cosmic void regions and whether we can quantitatively and qualitatively compare the voids they find with dynamical information from the underlying matter distribution. Using the ORIGAMI algorithm to determine the number of dimensions along which dark matter particles have undergone shell-crossing (crossing number) in N-body simulations from the AbacusSummit simulation suite, we identify dark matter particles that have undergone no shell crossing as belonging to voids. We then find voids in the corresponding halo distribution using two different void-finding algorithms: VoidFinder and Voronoi Voids (V2), a ZOBOV-based algorithm. The resulting void catalogs are compared to the distribution of dark matter particles to examine how their crossing numbers depend on void proximity. While both algorithms' voids have a similar distribution of crossing numbers near their centers, we find that beyond 0.25 times the effective void radius, voids found by VoidFinder exhibit a stronger preference for particles with low crossing numbers than those found by V2. We examine two possible methods of mitigating this difference in efficacy between the algorithms. While we are able to partially mitigate the ineffectiveness of V2 by using the distance from the void edge as a measure of centrality, we conclude that VoidFinder more reliably identifies dynamically distinct regions of low crossing number.
title A Comparison of Void-Finding Algorithms using Crossing Numbers
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2302.05469