Probing internal dissipative processes of neutron stars with gravitational waves during the inspiral of neutron star binaries

Understand

We study the impact of out-of-equilibrium, dissipative effects on the dynamics of inspiraling neutron stars.

• We find that modeling dissipative processes (such as those from the stars internal effective fluid viscosity) requires that one introduce a new tidal deformability parameter--the dissipative tidal deformability--which modifies the phase of gravitational waves emitted during the inspiral phase of a neutron star binary.
• We show that the dissipative tidal deformability corrects the gravitational-wave phase at 4 post-Newtonian order for quasi-circular binaries.
• This correction receives a large finite-size enhancement by the stellar compactness, analogous to the case of the tidal deformability.