Skyrme representation of a relativistic spin-orbit field

Abstract
We find that a spin-orbit force with the conventional Skyrme form reproduces satisfactorily the isospin dependence of the spin-orbit field generated in relativistic Hartree calculations on semi-infinite nuclear matter with different neutron excesses. We also examine a generalization of the Skyrme-type energy-density functional that leads to still better agreement with the relativistic Hartree calculations.