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. We investigate the bulk viscous dissipation timescales in a post-merger object and identify regimes where these timescales are as short as the characteristic timescale $\sim$10 ms, and, therefore, might affect the evolution of the post-merger object. Our analysis indicates that bulk viscous damping would be important at not too high temperatures of the order of a few MeV and densities up to a few times saturation density.
Binary neutron star mergers with SPHINCS_BSSN: temperature-dependent equations of state and damping of constraint violations
Hamburger Sternwarte（汉堡天文台）；The Oskar Klein Centre, Department of Astronomy, Stockholm University（斯德哥尔摩大学奥斯卡·克莱因中心天文学系）；Center for Computation & Technology, Louisiana State University（路易斯安那州立大学计算与技术中心）；Department of Physics & Astronomy, Louisiana State University（路易斯安那州立大学物理与天文学系）
Burgers equation for the bulk viscous pressure of quark matter
Institute of Space Sciences (ICE, CSIC)（空间科学研究所）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究学院）；Facultat de Física, Universitat de Barcelona（巴塞罗那大学物理学院）
