We study the role that the future detection of the neutrino burst from a galactic supernova can play in the reconstruction of the neutrino mass spectrum. We consider all possible 3ν mass and flavor spectra which describe the solar and atmospheric neutrino data. For each of these spectra we find the observable effects of the supernova neutrino conversions both in the matter of the star and the e...

Particle and nuclear physicists devoted an increasingly intensive effort during the last few decades to searching for evidence of neutrino mass. Recent announcements by the Superkamiokande collaboration of the possible oscillation of atmospheric neutrinos [1] and very high statistics measurements of the solar neutrinos [2] brought us one step closer to understanding the nature of neutrino mass ...

We stress the point that massive neutrinos may be Majorana particles even if the effective mass of the neutrinoless double beta decay 〈m〉ee vanishes. We show that current neutrino oscillation data do allow 〈m〉ee = 0 to hold, if the Majorana CP-violating phases lie in two specific regions. Strong constraints on the neutrino mass spectrum can then be obtained. A possible texture of the neutrino m...

We present a concise formula to relate the effective mass term of the neutrinoless double beta decay to a single neutrino mass, two Majorana CP-violating phases and four observables of neutrino oscillations for a generic neutrino mass spectrum. If the alleged evidence for the neutrinoless double beta decay is taken into account, one may obtain a rough but model-independent constraint on the abs...

We review previous work on neutrino mass textures in gauge theories. Such textures may arise as a result of flavour symmetries. In a given theory, it is possible to give a classification of heavy Majorana neutrino mass matrices, assuming the Dirac masses of the neutrinos to be of the same form as the ones of the up-quarks. Heavy Majorana neutrino mass matrices leading to large neutrino mixing, ...

A brief sketch is given of the present observational status and future prospects of the physics of neutrino mass, including a survey of the various theoretical schemes of neutrino mass generation. Emphasis is given to those which are motivated by present experimental hints from solar and atmospheric neutrinos, as well as from cosmological data related to the dark matter question. The conceptual...

In view of the recently reported evidence for a nonzero Majorana mass of the electron neutrino, together with the established phenomena of atmospheric and solar neutrino oscillations, the case of three nearly mass-degenerate Majorana neutrinos is now a distinct possibility. I show in this paper how a natural pattern of symmetry breaking in the recently proposed A4 model of Majorana neutrino mas...

We study the discovery potential of future beta decay experiments on searches for the neutrino mass in the sub-eV range, and, in particular, KATRIN experiment with sensitivity m > 0.3 eV. Effects of neutrino mass and mixing on the beta decay spectrum in the neutrino schemes which explain the solar and atmospheric neutrino data are discussed. The schemes which lead to observable effects contain ...

The lectures describe several cosmological effects produced by neutrinos. Upper and lower cosmological limits on neutrino mass are derived. The role that neutrinos may play in formation of large scale structure of the universe is described and neutrino mass limits are presented. Effects of neutrinos on cosmological background radiation and on big bang nucleosynthesis are discussed. Limits on th...

The importance of non-zero neutrino mass as a probe of particle physics, astrophysics, and cosmology is emphasized. The present status and future prospects for the solar and atmospheric neutrinos are reviewed, and the implications for neutrino mass and mixing in 2, 3, and 4-neutrino schemes are discussed. The possibilities for significant mixing between ordinary and light sterile neutrinos are ...