Neutrino oscillations, seesaw mechanism and the quest for new physics

The historical discovery of neutrino oscillationsusing solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, have brought neutrino physics to the precision era. Apart from dedicated leptonic CP violationstudies, upcoming experiments should probe the unitarityof the leptonmixing matrix. These will shed light on the scale of new physics, such as the seesaw scale, and thereby guide us towards what could be the next step in particle physics. Moreover these efforts may also bring the key to elucidate some of the current cosmological puzzles.