Neutron star merger, gravitational waves, and the dense matter equation of state*

The equation of state of dense matter that determines properties of the neutron star also characterizes the dynamics and gravitational waveforms emitted during binary neutron-star mergers. Understanding the effects of the equation of state on them requires numerical-relativity simulations of the mergers and a number of strategies for extracting information of equation of sate from gravitational waves have been proposed. Furthermore, recent numerical-relativity simulations also clarified that the neutron-star equation of state has a significant impact on the r-process nucleosynthesis which proceeds in the neutron-rich ejecta of the mergers. The r-process in the mergers has been accumulated wide interests both as a possible origin of heavy nuclei and a promising electro-magnetic counterpart to gravitational waves. I will review these topics and discuss possible feedbacks to the nuclear physics.