Bulk viscosity in neutron star mergers
Steven Harris (Hosted by Piarulli), Institute of Nuclear Theory
Bulk viscosity in nuclear matter arises from a phase lag between an imposed density oscillation and the reestablishment of beta equilibrium, which proceeds via the Urca process. When bulk viscosity is sufficiently strong, which happens when the reequilibration rate nearly matches the frequency of the density oscillation, the oscillation can be significantly damped. I will discuss the conditions inside neutron star mergers, and then discuss a calculation of the bulk viscosity in uniform nuclear matter. We find that in certain thermodynamic conditions, bulk viscosity can damp density oscillations on timescales relevant for neutron star mergers.