  Some issues regarding low energy neutrinos are reviewed. We focus on three
aspects i)We show that by employing very low energy (a few keV) electron
neutrinos, neutrino disappearance oscillations can be investigated by detecting
recoiling electrons with low threshold spherical gaseous TPC's. In such an
experiment, which is sensitive to the small mixing angle theta13, the novel
feature is that the oscillation length is so small that the full oscillation
takes place inside the detector. Thus one can determine accurately all the
oscillation parameters and, in particular, measure or set a good limit on
theta13. ii) Low threshold gaseous TPC detectors can also be used in detecting
nuclear recoils by exploiting the neutral current interaction. Thus these
robust and stable detectors can be employed in supernova neutrino detection.
iii) The lepton violating neutrinoless double decay is investigated focusing on
how the absolute neutrino mass can be extracted from the data
