Exploring the Cosmic Neutrino Background Anisotropies

This Thesis will explore various physical properties of the Cosmic Neutrino Background (CNB). The first part of the Thesis will provide a general overview, focusing on the most important cosmological aspects, including present observational constraints. The second part of the Thesis will focus on the original development of an aspect that recently is gaining attention both in the cosmological and in the particle physics community, namely the possibility to constrain (and in the future to detect) spatial anisotropies of the CNB. The second part of the Thesis in particular will investigate the cross-correlations of the CNB anisotropies with the temperature anisotropies of the Cosmic Microwave Background photons. We show how the cross-correlation between the Cosmic Neutrino Background represents a probe to determine the absolute mass scale of the neutrino and to find out the neutrino mass ordering. The CNB-CMB cross-correlation is a good observable to determine the absolute mass of the electron neutrino already at low multipoles.