Neutron star equation of state via gravitational wave observations

TL;DR

Gravitational wave observations of neutron star mergers can reveal the stars' internal structure by analyzing waveform deviations, enabling constraints on the neutron star equation of state through late-inspiral phase measurements.

Contribution

This study demonstrates how gravitational wave data can be used to measure neutron star compactness and constrain their equations of state by analyzing inspiral waveforms.

Findings

Waveform phase accelerates with increased compactness.

Observations around 1 kHz frequency are optimal for measuring neutron star properties.

Advanced detectors can effectively probe the late-inspiral phase for EOS constraints.

Abstract

Gravitational wave observations can potentially measure properties of neutron star equations of state by measuring departures from the point-particle limit of the gravitational waveform produced in the late inspiral of a neutron star binary. Numerical simulations of inspiraling neutron star binaries computed for equations of state with varying stiffness are compared. As the stars approach their final plunge and merger, the gravitational wave phase accumulates more rapidly if the neutron stars are more compact. This suggests that gravitational wave observations at frequencies around 1 kHz will be able to measure a compactness parameter and place stringent bounds on possible neutron star equations of state. Advanced laser interferometric gravitational wave observatories will be able to tune their frequency band to optimize sensitivity in the required frequency range to make sensitive measures of the late-inspiral phase of the coalescence.