Density and spin-density excitations in normal-liquid He-3

In bulk Fermi liquids such as liquid He-3 and nuclear matter the quasiparticle effective mass is enhanced at the Fermi surface and reduces to the bare mass far from the Fermi surface. We incorporate this central physical feature into the density and spin-density dynamics of normal-liquid He-3 and obtain good agreement with recent high-resolution neutron-scattering experiments. Existing theories up to this time using quadratic quasiparticle dispersion do not reproduce experiment.