  We formulate microscopic neutron-nucleus optical potentials from many-body
perturbation theory based on chiral two- and three-body forces. The neutron
self energy is first calculated in homogeneous matter to second order in
perturbation theory, which gives the central real and imaginary terms of the
optical potential. The real spin-orbit term is calculated separately from the
density matrix expansion using the same chiral interaction as in the self
energy. Finally, the full neutron-nucleus optical potential is derived within
the improved local density approximation utilizing mean field models consistent
with the chiral nuclear force employed. We compare the results of the
microscopic calculations to phenomenological models and experimental data up to
projectile energies of $E = 200$ MeV. Experimental elastic differential
scattering cross sections and vector analyzing powers are generally well
reproduced by the chiral optical potential, but we find that total cross
sections are overestimated at high energies.
