Abstract

Over the past 2–3 decades, gravitational lensing by galaxy clusters has played various key roles in astronomy and astrophysics. These include, primarily, mapping the otherwise-invisible dark matter distribution in the clusters or weighing them for constraining structure formation and cosmology; as well as enabling a deeper view into high-redshift galaxies, thanks to lensing magnification. Over the past few years there have been some new, exciting developments that allow for more unprecedented science using strong lensing — involving caustic crossing events and highly magnified distant stars (most notably perhaps Earendel, a single highly magnified star at z=6.2!), or lensed transients such as supernovae, gamma-ray bursts, fast radio bursts, and gravitational waves. In this talk I will review some of these advancements, as well as take the opportunity to mention some relevant programs in which we are involved.