  The isospin- and momentum-dependent MDI interaction, which has been
extensively used in intermediate-energy heavy-ion reactions to study the
properties of asymmetric nuclear matter, is extended to include the
nucleon-hyperon and hyperon-hyperon interactions by assuming same density,
momentum and isospin dependence as for the nucleon-nucleon interaction. The
parameters in these interactions are determined from the empirical hyperon
single-particle potentials in symmetric nuclear matter at saturation density.
The extended MDI interaction is then used to study in the mean-field
approximation the equation of state of hypernuclear matter and also the
properties of hybrid stars by including the phase transition from the
hypernuclear matter to the quark matter at high densities. In particular, the
effects of attractive and repulsive $\Sigma$N interactions and different values
of symmetry energies on the hybrid star properties are investigated.
