Preliminary forecasting constraint on scalar charge with LISA in non-vacuum environments

TL;DR

This paper investigates how scalar charges in EMRIs within non-vacuum environments affect gravitational wave signals, and predicts LISA's potential to constrain scalar charge with high precision.

Contribution

It introduces a method to compute gravitational waveforms from scalar-charged EMRIs in realistic astrophysical environments, extending previous vacuum-based models.

Findings

LISA can constrain scalar charge to about 0.1 accuracy.

Scalar charge effects are distinguishable from vacuum cases.

Environmental factors influence waveform modifications.

Abstract

We compute the gravitational wave signal from eccentric extreme-mass-ratio inspirals (EMRIs) embedded within beyond-vacuum environments, where the secondary object carries a scalar charge and evolves in the presence of both an accretion disk and a dark matter halo. The waveform modification is derived by incorporating the scalar charge correcting the fluxes and orbital trajectories of the secondary. Our results indicate that, under suitable parameter configurations, the influence of the scalar charge on EMRIs waveform in such environments can be distinguished from that in vacuum spacetime. For the EMRIs signal modified by the astrophysical environments, the future space-borne detector can determine the relative error of scalar charge constrained by LISA at the level of $\sim0.1$, providing a preliminary prediction of detecting scalar charge in the beyond-vacuum spacetime.