COLLECTIVE MODES IN RELATIVISTIC NUCLEAR-MATTER - CLASSICAL APPROACH

A classical relativistic approach based in the Vlasov equation is applied to the study of infinite nuclear matter. Hadronic matter couples to massive scalar and vector fields. The small-amplitude oscillations around a stationary state are studied. Orthogonality and completeness relations and the energy-weighted sum rule are obtained for the longitudinal modes. The appearance of the zero-sound mode and the distribution of the strength among the different modes are discussed. It is seen that the scalar field only couples to the low-energy excitations at high densities and for wavelengths not too long. The vector field couples strongly to the low-energy excitations. The long-wavelength limit and high-density limit are studied.