Quantum effects on right-handed neutrino parameters and phenomenological implications

Neutrino oscillations experiments show that at least two neutrinos have a tiny but non-zero mass. The seesaw mechanism can explain the smallness of neutrino masses by introducing heavy right-handed neutrinos (RHNs). This thesis studies quantum effects to generate RHN mass scales and the impact on the low-energy phenomenology of the light neutrinos through the seesaw mechanism. Phenomenological implications are explored in basic seesaw models and in seesaw models with extended scalar sectors.