Inferring the neutron star equation of state from binary inspiral waveforms

TL;DR

This paper demonstrates that gravitational wave observations from binary neutron star inspirals can be used to infer the neutron star equation of state by analyzing waveform differences at high frequencies.

Contribution

It introduces a method to extract neutron star matter properties from gravitational wave signals by comparing numerical waveforms for different equations of state.

Findings

High-frequency gravitational wave observations can constrain neutron star compactness.

Waveform differences are detectable with current and upcoming interferometers.

Measurements can distinguish between different neutron star equations of state.

Abstract

The properties of neutron star matter above nuclear density are not precisely known. Gravitational waves emitted from binary neutron stars during their late stages of inspiral and merger contain imprints of the neutron-star equation of state. Measuring departures from the point-particle limit of the late inspiral waveform allows one to measure properties of the equation of state via gravitational wave observations. This and a companion talk by J. S. Read reports a comparison of numerical waveforms from simulations of inspiraling neutron-star binaries, computed for equations of state with varying stiffness. We calculate the signal strength of the difference between waveforms for various commissioned and proposed interferometric gravitational wave detectors and show that observations at frequencies around 1 kHz will be able to measure a compactness parameter and constrain the possible neutron-star equations of state.