  The liquid-gas phase transition in hot asymmetric nuclear matter is studied
within density-dependent relativistic mean-field models where the density
dependence is introduced according to the Brown-Rho scaling and constrained by
available data at low densities and empirical properties of nuclear matter. The
critical temperature of the liquid-gas phase transition is obtained to be 15.7
MeV in symmetric nuclear matter falling on the lower edge of the small
experimental error bars. In hot asymmetric matter, the boundary of the
phase-coexistence region is found to be sensitive to the density dependence of
the symmetry energy. The critical pressure and the area of phase-coexistence
region increases clearly with the softening of the symmetry energy. The
critical temperature of hot asymmetric matter separating the gas phase from the
LG coexistence phase is found to be higher for the softer symmetry energy.
