# Redshift drift of gravitational lensing

## TL;DR

This paper studies how redshift drift impacts strong gravitational lensing, causing observable changes in source positions and time delays, which could be significant for cosmological measurements.

## Contribution

It introduces the concepts of angular drift and time delay drift in gravitational lensing due to redshift evolution, highlighting their potential cosmological importance.

## Key findings

- Redshift drift causes measurable shifts in source positions.
- Time delays between images are affected by redshift changes.
- These effects could influence cosmological parameter estimation.

## Abstract

We investigate the effect of the redshift drift in strong gravitational lensing. The redshift drift produces a time variation of $i)$ the apparent position of a lensed source and $ii)$ the time delay among incoming signals from different images. We dub these effects as angular drift and time delay drift, respectively, and analyze their relevance in cosmology.