Probing Strong-Field Scalar-Tensor Gravity with Gravitational Wave Asteroseismology

TL;DR

This paper proposes using gravitational wave asteroseismology of neutron stars to detect and constrain scalar fields in strong-field gravity, highlighting significant spectral differences caused by scalar-tensor theories.

Contribution

It introduces a novel method to probe scalar fields via neutron star oscillation spectra, offering a potential observational test for scalar-tensor gravity theories.

Findings

Scalar fields cause dramatic changes in neutron star oscillation spectra.

Gravitational wave observations can constrain scalar field existence and strength.

Spectral differences exceed uncertainties from equations of state.

Abstract

We present an alternative way of tracing the existence of a scalar field based on the analysis of the gravitational wave spectrum of a vibrating neutron star. Scalar-tensor theories in strong-field gravity can potentially introduce much greater differences in the parameters of a neutron star than the uncertainties introduced by the various equations of state. The detection of gravitational waves from neutron stars can set constraints on the existence and the strength of scalar fields. We show that the oscillation spectrum is dramatically affected by the presence of a scalar field, and can provide unique confirmation of its existence.