  The Rashba$^4$ model is a lattice model of interacting fermions with a
tight-binding dispersion relation that exhibits four Rashba band crossing
points at the same energy. The fermions interact weakly, by an on-site
repulsion and an additional nearest-neighbour two-body interaction, which may
be attractive or repulsive. We study this model when the Fermi energy is at or
close to the band crossings, by a combination of renormalization group flow
equations and mean-field theory. We find that the scattering processes between
different Rashba points drive superconductivity of an unusual triplet type not
found in models with a single Rashba point.
