Abhishek Hegade

University of Illinois Urbana-Champaign, November 17, 12:00 pm

Probing dissipative effects in neutron stars using gravitational waves

Tidal interactions in binary neutron star systems allow us to extract information about the equation of state inside a neutron star from gravitational wave observations. In this talk, we discuss how one could potentially probe out-of-equilibrium effects inside a neutron star by modeling the effects of tidal dissipation during the inspiral of a binary neutron star system. To account for dissipative effects such as viscosity, we introduce a new dissipative tidal deformability parameter and show that this term contributes to the gravitational wave phase at the 4th post-Newtonian (PN) order for quasi-circular binaries. This contribution receives a large finite-size enhancement by the stellar compactness, analogous to the case of the tidal deformability, which makes the parameter potentially measurable with ground-based gravitational wave detectors. In this talk, we will discuss our derivation of this result and then discuss our ongoing work on computing the impact of shear and bulk viscosity on the dissipative tidal deformability of neutron stars in general relativity.