  We compare nuclear and neutron matter predictions based on two different ab
initio approaches to nuclear forces and the nuclear many-body problem. The
first consists of a realistic meson-theoretic nucleon-nucleon potential
together with the relativistic counterpart of the Brueckner-Hartree-Fock theory
of nuclear matter. The second is based on chiral effective field theory, with
density-dependent interactions derived from leading order chiral three-nucleon
forces. We find the results to be very close and conclude that both approaches
contain important features governing the physics of nuclear and neutron matter.
