Dispersion relations at finite temperature and density for nucleons and pions

We calculate the nucleonic and pionic dispersion relations at finite temper ature (T) and non-vanishing chemical potentials (mu(f)) in the context of a n effective chiral theory that describes the strong and electromagnetic int eractions for nucleons and pions. The dispersion relations are calculated i n the broken chiral symmetry phase, where the nucleons are massive and pion s are taken as massless. The calculation is performed at lowest order in th e energy expansion, working in the framework of the real time formalism of thermal field theory in the Feynman gauge. These one-loop dispersion relati ons are obtained at leading order with respect to T and mu(f). We also eval uate the effective masses of the quasi-nucleon and quasi-pion excitations i n thermal and chemical conditions as the ones of a neutron star.