Bulk Viscous Damping of Density Oscillations in Neutron Star Mergers

Understand

In this paper, we discuss the damping of density oscillations in dense nuclear matter in the temperature range relevant to neutron star mergers.

• This damping is due to bulk viscosity arising from the weak interaction ``Urca'' processes of neutron decay and electron capture.
• The nuclear matter is modelled in the relativistic density functional approach.
• The bulk viscosity reaches a resonant maximum close to the neutrino trapping temperature, then drops rapidly as temperature rises into the range where neutrinos are trapped in neutron stars.