Sampling in Pressure for Compatibility with Inferring Multi-Branch Neutron Star Equations of State from Gravitational Waves

Neutron stars have densities far beyond those of an atomic nucleus. Observing neutron stars from a distance is the main way that we can learn how matter behaves when packed this tightly. In addition to the light that some of them (mainly pulsars) emit toward us, we can observe neutron stars through the gravitational wave signals emitted when they merge with each other. Because the stretching of the neutron stars due to tidal forces hastens part of the coalescence process, the gravitational wave data helps us to constrain the neutron star equation of state, which describes how compressible neutron star material is. The current software used by the LIGO Scientific Collaboration for this analysis cannot handle equations of state with multiple branches. This project alters the code to sample in pressure space instead of in mass space, an important step for making it work with multiple branches.