PIONS IN THE NUCLEAR MEDIUM

We discuss various aspects of pion physics in the nuclear medium. We f irst study s-wave pion-nucleus interaction in connection with chiral s ymmetry restoration and quark condensate in the nuclear medium. We the n adress the question of p-wave pion-nucleus interaction and collectiv e pionic modes in nuclei and draw the consequences for in medium pi pi correlations especially in the scalar-isoscalar channel. We finally d iscuss the modification of the rho meson mass spectrum at finite densi ty and/or temperature in connection with relativistic heavy ion collis ions.