Spinodal instabilities in nuclear matter in a stochastic relativistic mean-field approach

Spinodal instabilities and early growth of baryon density fluctuations in symmetric nuclear matter are investigated in the basis of the stochastic extension of the relativistic mean-field approach in the semiclassical approximation. Calculations are compared with the results of nonrelativistic calculations based on Skyrme-type effective interactions under similar conditions. A qualitative difference appears in the unstable response of the system: the system exhibits most unstable behavior at higher baryon densities around rho(b) = 0.4 rho(0) in the relativistic approach while most unstable behavior occurs at lower baryon densities around rho(b) = 0.2 rho(0) in the nonrelativistic calculations