Prediction for the neutrino mass in the KATRIN experiment from lensing by the galaxy cluster A1689

The KATRIN experiment in Karlsruhe Germany will monitor the decay of tritium,
which produces an electron-antineutrino. While the present upper bound for its mass is
2 eV/c2, KATRIN will search down to 0.2 eV=c2. If the dark matter of the galaxy cluster
Abell 1689 is modeled as degenerate isothermal fermions, the strong and weak lensing
data may be explained by degenerate neutrinos with mass of 1.5 eV=c2. Strong lensing
data beyond 275 kpc put tension on the standard cold dark matter interpretation. In
the most natural scenario, the electron antineutrino will have a mass of 1.5 eV/c2, a
value that will be tested in KATRIN.