  The scattering matrix which describes low-energy, non-relativistic scattering
of spin-1/2 fermions interacting via finite-range potentials can be obtained
from a geometric action principle in which space and time do not appear
explicitly arXiv:2011.01278. In the case of zero-range forces, causality leads
to constraints on scattering trajectories in the geometric picture. The effect
of spatial dimensionality is also investigated by considering scattering in two
and three dimensions. In the geometric formulation it is found that
dimensionality is encoded in the phase of the harmonic potential that appears
in the geometric action.
