Induced motions on Carroll geometries

In this article, we consider some Carrollian dynamical systems as effective models on null hypersurfaces in a Lorentzian spacetime. We show that we can realize Carroll models from more usual ``relativistic'' theories. In particular, we show how ambient null geodesics imply the classical ``no Carroll motion'' and, more interestingly, we find that the ambient model of chiral fermions implies Hall motion on null hypersurfaces, in agreement with previous intrinsic Carroll results. We also show how Wigner-Souriau translations imply (apparent) Carroll motion, and how ambient particles with a non vanishing gyromagnetic ratio cannot have a Carrollian description.