Implementing a Dynamic Polytrope Model of Neutron Star Equation of State in BILBY*

This research develops and validates bayesian inference software to constrain the neutron star equation of state (EOS) from LIGO's measurements of tidal deformability encoded in gravitational waves emitted by neutron star mergers. Formerly, LIGO measured source parameters of astrophysical systems that emit gravitational waves with a software package known as LALInference. LIGO has since moved to the new software package BILBY, which is designed to have a more user-friendly interface and has packages tailored specifically to parameter estimation of compact binary coalescence events.  However, direct EOS inference has not yet been incorporated into BILBY. This research implements a 3 piece dynamic polytrope model in BILBY to sample in EOS parameters. We test this model alongside another model that was used by LALInference and compare both to previous work. With this software in place, LIGO will be able to constrain the neutron star equation of state with data from past and future binary NS mergers.