Preface to theme issue about multi-messenger gravitational lensing

Abstract

Multi-messenger gravitational lensing combines multi-messenger astronomy with gravitational lensing. The first gravitational lensing observations occurred during the 1919 total solar eclipse, and were published in the Philosophical Transactions of the Royal Society A, thus providing early support for Einstein’s theory of General Relativity [1]. Systematic observations of gravitational lenses—beyond the Solar System and the Local Group—began decades later in the late twentieth century [2–4]. The ground-breaking detections of neutrinos from the Sun and SN1987A occurred on a similar timescale [5–9], marking the dawn of multi-messenger astronomy. This field experienced a spectacular renaissance three decades later when gravitational waves (GWs), and electromagnetic (EM) radiation from gamma rays to radio waves were detected from a binary neutron star (BNS) merger in 2017 [10,11]. The first confirmed discoveries of gravitationally lensed transient sources, and the first detection of neutrinos from an extragalactic source were both achieved in parallel with the early GW discoveries [12–14].