2023-09-08 11:00  P5A-1

Cosmic Voids as Counterpart of Massive Clusters

Dr. Junsup Shim

In this talk, I will present a method to identify cosmic voids from matter/galaxy density fields by adopting a physically-motivated void-cluster correspondence theory that voids are the counterpart of massive clusters. To prove the concept we use a pair of LCDM simulations, a reference and its initial density-inverted mirror simulation, and study the relation between the effective size of voids and the mass of corresponding clusters. We study the voids corresponding to the halos more massive than 10¹³M☉/h and find a power-law scaling relation between the void size and the corresponding cluster mass. We also find that the density profile of the identified voids follows a universal functional form. Based on these findings, we propose a method to identify cluster-counterpart voids directly from the matter/galaxy density field without their mirror information. Using this method, we achieve 70-74% (60-67%) of completeness and reliability in recovering voids corresponding to clusters more massive than 3×10¹⁴M☉/h from a given matter (galaxy) density field. Our results demonstrate that we can apply this method to the galaxy redshift survey data to identify cosmic voids corresponding statistically to the galaxy clusters in a given mass range.