Wave effect of gravitational waves intersected with a microlens field: a new algorithm and supplementary study

TL;DR

This paper introduces a new, faster algorithm to analyze wave effects in gravitational lensing caused by microlenses within galaxy clusters, improving the accuracy and efficiency of studying strong lensing signals in gravitational wave data.

Contribution

The work presents a novel algorithm that enhances the speed and accuracy of wave optics calculations for microlenses in complex lensing environments, with a quantitative boundary estimation criterion.

Findings

Algorithm significantly reduces computational time.

Improves accuracy in wave optics simulations.

Facilitates large-scale statistical studies of microlensing effects.

Abstract

The increase in gravitational wave (GW) events has allowed receiving strong lensing image pairs of GWs. However, the wave effect (diffraction and interference) due to the microlens field contaminates the parameter estimation of the image pair, which may lead to a misjudgment of strong lensing signals. To quantify the influence of the microlens field, researchers need a large sample of statistical research. Nevertheless, due to the oscillation characteristic, the Fresnel-Kirchhoff diffraction integral's computational time hinders this aspect's study. Although many algorithms are available, most cannot be well applied to the case where the microlens field is embedded in galaxy/galaxy clusters. This work proposes a faster and more accurate algorithm for studying the wave optics effect of microlenses embedded in different types of strong lensing images. Additionally, we provide a quantitative estimation criterion for the lens plane boundary for the Fresnel-Kirchhoff diffraction integral. This algorithm can significantly facilitate the study of wave optics, particularly in the case of microlens fields embedded in galaxy/galaxy clusters.