Exploring waveforms with non-GR deviations for extreme mass-ratio inspirals

TL;DR

This paper investigates how non-GR deviations in black hole waveforms affect extreme mass-ratio inspirals, aiming to detect deviations from general relativity using LISA observations.

Contribution

It introduces a refined, pathology-free deformed Kerr geometry to analyze gravitational waveforms and assess the detectability of deviations from GR in EMRI systems.

Findings

Deformation parameters influence orbital energy and angular momentum rates.

Waveform analysis can constrain deviations from GR.

LISA observations could detect non-GR signatures in EMRIs.

Abstract

The fundamental process of detecting and examining the polarization modes of gravitational waves plays a pivotal role in enhancing our grasp on the precise mechanisms behind their generation. A thorough investigation is essential for delving deeper into the essence of gravitational waves and rigorously evaluating and validating the range of modified gravity theories. In this line of interest, a general description of black holes in theories beyond general relativity can serve a meaningful purpose where distinct deviation parameters can be mapped to solutions representing distinct theories. Employing a refined version of the deformed Kerr geometry, which is free from pathological behaviours such as unphysical divergences in the metric, we explore an extreme mass-ratio inspiral system, wherein a stellar-mass object perturbs a supermassive black hole. We compute the effects of deformation parameters on the rate of change of orbital energy and angular momentum, orbital evolution and phase dynamics with leading order post-Newtonian corrections. With the waveform analysis, we assess the plausibility of detecting deviations from general relativity through observations facilitated by the Laser Interferometer Space Antenna (LISA), simultaneously constraining the extent of these deviations. Therefore, this analysis provides an understanding while highlighting the essential role of observations in advancing gravitational phenomena beyond general relativity.