Effect of Deviations from General Relativity on Searches for Gravitational Wave Microlensing and Type II Strong Lensing

TL;DR

This paper investigates how deviations from general relativity could mimic gravitational lensing signals in gravitational wave data, emphasizing the importance of careful analysis to avoid false positives in future detections.

Contribution

It demonstrates that phenomenological deviations from general relativity can be mistaken for gravitational lensing effects, highlighting the need for careful interpretation of future gravitational wave events.

Findings

Deviations from general relativity can mimic lensing signatures.

Future lensing candidates require thorough analysis to distinguish from GR deviations.

Potential for false positives in gravitational wave lensing searches due to GR deviations.

Abstract

As the gravitational wave detector network is upgraded and the sensitivity of the detectors improves, novel scientific avenues open for exploration. For example, tests of general relativity will become more accurate as smaller deviations can be probed. Additionally, the detection of lensed gravitational waves becomes more likely. However, these new avenues could also interact with each other, and a gravitational wave event presenting deviations from general relativity could be mistaken for a lensed one. Here, we explore how phenomenological deviations from general relativity or binaries of exotic compact objects could impact those lensing searches focusing on a single event. We consider strong lensing, millilensing, and microlensing and find that certain phenomenological deviations from general relativity may be mistaken for all of these types of lensing. Therefore, our study shows that future candidate lensing events would need to be carefully examined to avoid a false claim of lensing where instead a deviation from general relativity has been seen.