  The properties of nuclear matter are studied using state-of-the-art
nucleon-nucleon forces up to fifth order in chiral effective field theory. The
equations of state of symmetric nuclear matter and pure neutron matter are
calculated in the framework of the Brueckner-Hartree-Fock theory. We discuss in
detail the convergence pattern of the chiral expansion and the regulator
dependence of the calculated equations of state and provide an estimation of
the truncation uncertainty. For all employed values of the regulator, the
fifth-order chiral two-nucleon potential is found to generate nuclear
saturation properties similar to the available phenomenological high precision
potentials. We also extract the symmetry energy of nuclear matter, which is
shown to be quite robust with respect to the chiral order and the value of the
regulator.
