Role of particle diffusion in shaping the gravitational wave signal from neutron star inspirals

TL;DR

This paper investigates the impact of particle diffusion in superconducting neutron stars on gravitational wave signals, revealing that diffusion can significantly alter the waveform phase and increase stellar temperature during inspiral.

Contribution

It demonstrates that particle diffusion effects, often neglected, can notably influence gravitational waveforms and thermal states of neutron stars during inspiral.

Findings

Diffusion effects cause phase shifts of tens of milliradians at low frequencies.

Particle diffusion can raise neutron star temperature to about 10^7 K.

Diffusion impacts are significant enough to warrant inclusion in waveform modeling.

Abstract

It is commonly believed that the dissipative properties of superdense matter play a negligible role in modeling gravitational waveforms from neutron star inspirals. This study aims to investigate whether this presumption holds true for the often neglected dissipative process associated with particle diffusion in superconducting neutron stars. As we demonstrate, diffusion effects can significantly impact the phase of the gravitational wave from the inspiral, manifesting at a magnitude of a few tens of milliradians at large orbit separations, equivalent to orbital frequencies of a few hertz. We also find that dissipation resulting from particle diffusion might increase the neutron star's temperature to approximately $10^7\rm K$ during the inspiral.