Isovector vibrations in nuclear matter at finite temperature

We consider the propagation and damping of isovector excitations in heated nuclear matter within the Landau Fermi-liquid theory. Results obtained for nuclear matter are applied to calculate the giant dipole resonance (GDR) at finite temperature in heavy spherical nuclei within a Steinwedel and Jense n picture. The centroid energy of the GDR slightly decreases with increasin g temperature and the width increases as T-2 for temperatures T < 4 MeV in agreement with recent experimental data for GDR in Pb-208 and Sn-120. The v alidity of the method for other Fermi fluids is finally suggested.