Siri Chongchitnan (University of Hull, United Kingdom)
Cosmic voids have been shown to be an effective probe of cosmology, complementary to galaxy clusters. But how reliable are the current theoretical models for void abundance? In this talk, I will explain how the theory of "extreme cosmic voids" can be used as a consistency test for theories of void abundance. I will give a simple derivation of the size of the largest voids expected within a given redshift and volume. This extreme-void model is based on the exact extreme-value statistics which has previously been successfully applied to massive galaxy clusters. I will show that, when compared with simulations and observations (e.g. SDSS voids), the Sheth and Van de Weygaert model (and simple adjustments thereof) generally yields a poor fit to the extreme-void abundance even though it appears to give a good fit to the void distribution over some radius range. I will discuss some insights into possible resolutions. Based on 1502.07705 (JCAP in press).