Lorentz gauge, cutting arbitrary scalar fields out from the energy-momentum density tensor, opens a door to the invisible world of dark energy and dark matter. This path leads to the coupled Dirac equations on the mass shell, solutions of which are those of the Majorana fermions. From the other side, the Lambda + cold dark matter paradigm is a main step leading to getting the Majorana fermion mass. Three key parameters are involved in the formula for computing the mass. They are the critical density distribution of dark matter, the Planck constant, and the temperature of the cosmic microwave radiation. The mass calculated to be equal to about 0.04 eV is in good agreement with the masses measured for neutrino. The formula represents itself as the five-degree root from the above key parameters. It opens the existence of three Majorana fermion generations. These generations form wave modes that lead to the appearance of the Bose-Einstein condensate in this dark matter. For that reason, the baryon matter does not experience resistance when it is rotating in this dark superfluid medium. Orbital speeds of rotating about the galaxy core of its arms show the flat profile.