lensingGW: a Python package for lensing of gravitational waves

TL;DR

lensingGW is a Python package that enables systematic analysis of gravitational wave lensing, including strong and microlensing effects, facilitating the study of complex lens configurations and their impact on gravitational wave signals.

Contribution

the paper introduces lensingGW, a novel Python toolkit for modeling and analyzing both strong and microlensing of gravitational waves, expanding capabilities beyond existing limited configurations.

Findings

demonstrates lensingGW's ability to simulate microlensing effects

enables exploration of arbitrary lens configurations

facilitates systematic parameter space investigations

Abstract

Advanced LIGO and Advanced Virgo could observe the first lensed gravitational waves in the coming years, while the future Einstein Telescope could observe hundreds of lensed events. Ground-based gravitational-wave detectors can resolve arrival time differences of the order of the inverse of the observed frequencies. As LIGO/Virgo frequency band spans from a few $\rm Hz$ to a few $ \rm kHz$, the typical time resolution of current interferometers is of the order of milliseconds. When microlenses are embedded in galaxies or galaxy clusters, lensing can become more prominent and result in observable time delays at LIGO/Virgo frequencies. Therefore, gravitational waves could offer an exciting alternative probe of microlensing. However, currently, only a few lensing configurations have been worked out in the context of gravitational-wave lensing. In this paper, we present lensingGW, a Python package designed to handle both strong and microlensing of compact binaries and the related gravitational-wave signals. This synergy paves the way for systematic parameter space investigations and the detection of arbitrary lens configurations and compact sources. We demonstrate the working mechanism of lensingGW and its use to study microlenses embedded in galaxies.