Rapid neutron star equation of state inference with Normalising Flows

TL;DR

This paper introduces ASTREOS, a rapid and flexible method using Normalising Flows for inferring neutron star equations of state from gravitational wave data, achieving results in under a second.

Contribution

The paper presents a novel, fast, and non-parametric approach for neutron star equation of state inference using Normalising Flows, significantly reducing analysis time.

Findings

ASTREOS produces results consistent with traditional methods.

It requires less than 1 second to generate confidence intervals.

The method enables non-parametric inference of the neutron star equation of state.

Abstract

The first direct detection of gravitational waves from binary neutron stars on the 17th of August, 2017, (GW170817) heralded the arrival of a new messenger for probing neutron star astrophysics and provided the first constraints on neutron star equation of state from gravitational wave observations. Significant computational effort was expended to obtain these first results and therefore, as observations of binary neutron star coalescence become more routine in the coming observing runs, there is a need to improve the analysis speed and flexibility. Here, we present a rapid approach for inferring the neutron star equation of state based on Normalising Flows. As a demonstration, using the same input data, our approach, ASTREOS, produces results consistent with those presented by the LIGO-Virgo collaboration but requires < 1 sec to generate neutron star equation of state confidence intervals. Furthermore, ASTREOS allows for non-parametric equation of state inference. This rapid analysis will not only facilitate neutron star equation of state studies but can potentially enhance future alerts for electromagnetic follow-up observations of binary neutron star mergers.