Evaluating the influence of relic neutrinos on galaxy cluster evolution with cosmological simulations

Abstract

In this thesis, the effects of massive relic neutrinos on the two-point correlation functions of galaxy clusters are studied. By performing large-volume cluster formation simulations with relic neutrinos incorporated, large simulated samples of clusters are generated to study the sensitivity of cluster correlations to neutrino mass. The number of simulated clusters is comparable to the data expected to be observed by DESI and EUCLID, and our results serve as predictions for these surveys. An extended ΛCDM model with refitted parameters that includes Ω_ν is used, as well as a novel method that treats Ω_ν as a perturbation. We find that correlations are enhanced with increasing neutrino mass by the Kaiser bias predicted for a Gaussian random field at fixed cluster mass limits [1], while cluster abundance is reduced which corresponds to rarer peaks of an overdensity field. The evolution of cluster number density under various relic neutrino masses is predicted by our simulations, and compared with SDSS and HSC survey data. These results collectively provide comprehensive sensitivity to relic neutrino mass anticipated for ongoing high-redshift surveys.

Date of Award	2025
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Kirill PROKOFIEV (Supervisor)