Resonant shattering flares as asteroseismic tests of chiral effective field theory

TL;DR

This paper proposes using neutron star asteroseismic modes, especially crust-core interface modes, to test chiral effective field theory predictions at sub-saturation densities through gravitational-wave and flare observations.

Contribution

It introduces a novel method to constrain $ ext{chi}$EFT predictions at specific densities using neutron star oscillation measurements.

Findings

Crust-core interface mode frequency estimated at 185 ± 50 Hz by $ ext{chi}$EFT.

Asteroseismic observables can serve as tests for $ ext{chi}$EFT predictions.

Potential for multimessenger signals to validate nuclear matter models.

Abstract

Chiral effective field theory ($\chi$EFT) has proved to be a powerful microscopic framework for predicting the properties of neutron-rich nuclear matter with quantified theoretical uncertainties up to about twice the nuclear saturation density. Tests of $\chi$EFT predictions are typically performed at low densities using nuclear experiments, with neutron star (NS) constraints only being considered at high densities. In this work, we discuss how asteroseismic quasi-normal modes within NSs could be used to constrain specific matter properties at particular densities, not just the integrated quantities to which bulk NS observables are sensitive. We focus on the crust-core interface mode, showing that measuring this mode's frequency would provide a meaningful test of $\chi$EFT at densities around half the saturation density. Conversely, we use nuclear matter properties predicted by $\chi$EFT to estimate that this mode's frequency is around 185 $\pm$ 50 Hz. Asteroseismic observables such as resonant phase shifts in gravitational-wave signals and multimessenger resonant shattering flare timings, therefore, have the potential to provide useful tests of $\chi$EFT.