Gravitational waves from extreme mass ratio inspirals in Kerr-MOG spacetimes

TL;DR

This paper investigates how modified gravity (MOG) influences gravitational wave signals from extreme mass ratio inspirals (EMRIs) in Kerr-MOG spacetimes, highlighting the impact of deviations from general relativity on waveform characteristics.

Contribution

It provides a detailed analysis of EMRI waveforms in Kerr-MOG spacetimes using numerical simulations and explores the effects of MOG parameters on waveform features and distinguishability.

Findings

MOG parameter α significantly alters geodesic frequencies.

Waveform overlap decreases over time with radiation reaction effects.

Waveform confusion remains a challenge for theory discrimination.

Abstract

This work elaborates on a detailed analysis of the novel characteristics of gravitational waves (GWs) generated by extreme mass ratio inspirals (EMRIs) within the framework of modified gravity (MOG). Our study begins by exploring the geometrical and dynamical properties of the Kerr-MOG spacetime. We employ the numerical kludge (NK) method for waveform simulations and reveal that the parameter $\alpha$, representing deviations from general relativity (GR), significantly impacts the frequencies of geodesic orbits and, consequently, the EMRI waveforms. However, the waveform confusion problem remains mainly unresolved, posing a challenge in distinguishing between the underlying gravitational theories based on the observed EMRI waveforms. Notably, by incorporating the effects of radiation reaction, we observe a substantial reduction in the waveform overlap over time. This reduction could enhance our ability to discern between different waveforms over an extended period.