Probing fundamental physics with Extreme Mass Ratio Inspirals: a full Bayesian inference for scalar charge

TL;DR

This paper develops a Bayesian framework to analyze EMRI gravitational wave signals, aiming to detect potential scalar fields predicted by extensions of General Relativity, thereby advancing tests of fundamental physics with LISA.

Contribution

It introduces the first complete Bayesian analysis method for EMRI signals in theories with a massless scalar, including an accurate waveform model for equatorial eccentric orbits.

Findings

Forecasts LISA's sensitivity to scalar fields using Bayesian inference.

Provides a new waveform model for equatorial eccentric EMRIs.

Demonstrates potential to detect fundamental physics deviations.

Abstract

Extreme Mass Ratio Inspirals (EMRIs) are key sources for the future space-based gravitational wave detector LISA, and are considered promising probes of fundamental physics. Here, we present the first complete Bayesian analysis of EMRI signals in theories with an additional massless scalar, which could arise in an extension of General Relativity or of the Standard Model of Particle Physics. We develop a waveform model accurate at adiabatic order for equatorial eccentric orbits around spinning black holes. Using full Bayesian inference, we forecast LISA's ability to probe the presence of new fundamental fields with EMRI observations.