Placing constraints on the neutrino mass is an important goal in modern physics. One important limit on the neutrino mass can be deduced from the cosmological constraint on the formation of large scale structure as the neutrinos become nonrelativistic at late times. On the other hand we have shown that the development of large scale structure and the limits on the neutrino mass are also affecte...

There is a renewed interest in constraining the sum of the masses of the three neutrino flavours by using cosmological measurements. Solar, atmospheric, and reactor neutrino experiments have confirmed neutrino oscillations, implying that neutrinos have non-zero mass, but without pinning down their absolute masses. While it is established that the effect of light neutrinos on the evolution of co...

Naturalness of the neutrino mass hierarchy and mixing is studied. First we select among 12 neutrino mixing patterns a few patterns, which could form the natural neutrino mass matrix. Further we show that if the Dirac neutrino mass matrix is taken as the natural one in the quark sector, then only two mixing patterns without the large mixing lead to the natural right-handed Majorana mass matrix. ...

The simplest unified extension of the Minimal Supersymmetric Standard Model with bi-linear R–Parity violation naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino acquires mass by mixing with neutralinos, while the other two get mass radiatively. We have performed a full one-loop calculation of the neutralino-neutrino mass matrix in the bi-linear Rp / MSSM, taking spe...

Assuming three-neutrino mixing and massive Majorana neutrinos, we study the implications of the neutrino oscillation solutions of the solar and atmospheric neutrino problems and of the results of the CHOOZ experiment for the predictions of the effective Majorana mass in neutrinoless double beta ((ββ) 0ν-)decay, |< m >|. The general case of CP-nonconservation is investigated. The predicted value...

We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of the Majorana neutrino mass matrices. Unlike other extensions of the standard model, the structure is now independent of the effective Yukawa couplings and de...

The Long Baseline Neutrino Oscillation Experiment (LBNE) is proposed to determine the neutrino mass hierarchy and measure the CP phase δCP in the leptonic sector. The current design of LBNE Phase I consists of a 10 kt liquid argon time projection chamber (LBNE10). The neutrino-antineutrino asymmetry in the electron-neutrino appearance probability has contributions from both the CP phase and the...

A simple quantum mechanical model of neutrino oscillations fits all experimental data thus far, but the data is sparse enough to allow for many other possibilities. The mass-varying neutrino (MaVaN) model adds one heavy sterile neutrino with a mass proportional to a power of the electron number density. We study oscillations between two active neutrinos after integrating out the sterile neutrin...