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 Ων is used, as well as a novel method that treats Ων 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 cluster number density evolution under various relic neutrino masses is predicted by our simulations, with a preliminary comparison with HSC survey data. These results collectively provide comprehensive sensitivity to relic neutrino mass anticipated for ongoing high-redshift surveys.
[1] Kaiser, N. On the Spatial correlations of Abell clusters. Astrophys. J. Lett. 284, L9–L12 (1984).