Spin-polarized neutron-rich matter at different orders of chiral effective field theory

Spin-polarized neutron matter is studied using chiral two- and three-body forces. We focus, in particular, on predictions of the energy per particle in ferromagnetic neutron matter at different orders of chiral effective field theory and for different choices of the resolution scale. We discuss the convergence pattern of the predictions and their cutoff dependence. We explore to what extent fully polarized neutron matter behaves (nearly) like a free Fermi gas. We also consider the more general case of partial polarization in neutron matter as well as the presence of a small proton fraction. In other words, in our calculations, we vary both spin and isospin asymmetries. Confirming the findings of other microscopic calculations performed with different approaches, we report no evidence for a transition to a polarized phase of neutron matter.