Identification of Cosmic Voids as Massive Cluster Counterparts

Understand

We develop a method to identify cosmic voids from the matter density field by adopting a physically-motivated concept that voids are the counterpart of massive clusters.

• To prove the concept we use a pair of $\Lambda$CDM 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.
• Galaxy cluster-scale dark matter halos are identified in the Mirror simulation at $z=0$ by linking dark matter particles.
• The void corresponding to each cluster is defined in the Reference simulation as the region occupied by the member particles of the cluster.