Chiral effective field theory calculations of neutrino processes in dense matter

We calculate neutrino processes involving two nucleons at subnuclear densities using chiral effective field theory. Shorter range noncentral forces reduce the neutrino rates significantly compared with the one-pion exchange approximation currently used in supernova simulations. For densities ρ<10¹⁴ g cm^-3, we find that neutrino rates are well constrained by nuclear interactions and nucleon-nucleon scattering data. As an application, we calculate the mean-square energy transfer in scattering of a neutrino from nucleons and find that collision processes and spin-dependent mean-field effects dominate over the energy transfer due to nucleon recoil.