Transport in Neutron Star Mergers

Transport properties of compact stars have been computed in the past mostly for the conditions in old, isolated and therefore cold neutron stars. Gravitational wave observations of binary neutron star mergers allow us to examine dense matter in even denser, but more importantly significantly hotter matter. This requires a careful reexamination of nuclear and exotic transport properties of dense matter. In this talk I will present our work on nuclear and exotic bulk viscosity and Urca like processes in these environments.