ZOBOV: a parameter-free void-finding algorithm

TL;DR

ZOBOV is a parameter-free algorithm that identifies cosmic voids using Voronoi tessellation, effectively detecting voids and subvoids without shape assumptions, and assesses their statistical significance in large-scale simulations.

Contribution

The paper introduces ZOBOV, a novel void-finding method that operates without free parameters or shape assumptions, utilizing Voronoi tessellation and Poisson probability measures.

Findings

Successfully identified voids and subvoids in Millennium Simulation data.

Provided statistical significance for each detected void.

Discovered a high-density peak in dark matter density distribution.

Abstract

ZOBOV (ZOnes Bordering On Voidness) is an algorithm that finds density depressions in a set of points, without any free parameters, or assumptions about shape. It uses the Voronoi tessellation to estimate densities, which it uses to find both voids and subvoids. It also measures probabilities that each void or subvoid arises from Poisson fluctuations. This paper describes the ZOBOV algorithm, and the results from its application to the dark-matter particles in a region of the Millennium Simulation. Additionally, the paper points out an interesting high-density peak in the probability distribution of dark-matter particle densities.