Spin and density response functions for hot and dense nuclear matter from chiral nuclear forces

The response functions and associated dynamical structure factors of nuclear matter affect neutrino propagation in core-collapse supernovae and neutron star mergers. In this talk we will discuss new calculations of the spin and density response functions of beta equilibrium matter under a wide range of ambient conditions starting from realistic chiral nuclear forces. We include both mean field and vertex corrections at first order in many-body perturbation theory. The former have already been shown to significantly affect neutrino charged-current reactions in the neutrinosphere, and in the present work we highlight the role of vertex corrections that enter at the same order in perturbation theory. Theoretical uncertainties are estimated by varying the order in the chiral expansion and the high-momentum cutoff scale in the effective field theory expansion of the nuclear force. We expect the results of this study to provide theoretical guidance for neutrino reaction rates used in numerical simulations of supernovae and neutron star mergers.