Abstract:
In spite of all the successes of the Standard Model, it is unlikely to be the final theory. It leaves many unanswered questions. The minimal SM predicted vanishing of the neutrino mass, but the recent observations of neutrino oscillations confirm that neutrinos have finite masses providing a likely window to new physics beyond the standard model. There we will discuss possible theories of neutrino mass, from changes of the minimal SM all the way to the SU(5) and SO(10) grand unified theory. We shall discuss at length the see-saw mechanism which leads to neutrino Majorana mass, its realization in left-right symmetric theory and in SO(10).