Effects of waveform systematics on inferences of neutron star population properties and the nuclear equation of state

TL;DR

This paper examines how waveform systematics influence the inference of neutron star populations and the nuclear equation of state from gravitational wave data, highlighting the importance of model choice in parameter estimation.

Contribution

It compares different waveform models to assess their impact on population and nuclear matter inferences from gravitational wave observations.

Findings

Waveform model differences significantly affect parameter estimates.

Systematic uncertainties influence the inferred properties of neutron star populations.

Accurate waveform modeling is crucial for reliable nuclear equation-of-state constraints.

Abstract

Gravitational waves from inspiralling neutron stars carry information about matter at extreme gravity and density. The binary neutron star (BNS) event GW170817 provided, for the first time, insight into dense matter through this window. Since then, another BNS (GW190425) and several neutron star-black hole events have been detected, although the tidal measurements were not expected to be well-constrained from them. Collective information regarding the behavior of nuclear matter at extreme densities can be done by performing a joint population inference for the masses, spins, and equation-of-state [1] to enable better understanding. This population inference, in turn, relies on accurate estimates of intrinsic parameters of individual events. In this study, we investigate how the differences in parameter inference of BNS events using different waveform models can affect the eventual inference of the nuclear equation-of-state. We use the state-of-the-art model TEOBResumS with IMRPhenomD NRTidalv2 as a comparison model.