Strongly Lensed Transient Sources: A Review

Abstract

The past decades have witnessed a lot of progress in gravitational lensing with two main targets: stars and galaxies (with active galactic nuclei). The success is partially attributed to the continuous luminescence of these sources making the detection and monitoring relatively easy. With the running of ongoing and upcoming large facilities/surveys in various electromagnetic and gravitational-wave bands, the era of time-domain surveys would guarantee constant detection of strongly lensed explosive transient events, for example, supernovae in all types, gamma ray bursts with afterglows in all bands, fast radio bursts and even gravitational waves. Lensed transients have many advantages over the traditional targets in studying the Universe and magnification effect helps to understand the transients themselves at high redshifts. In this review article, basing on the recent achievements in the literature, we summarize the methods of searching for different kinds of lensed transient signals, the latest results on detection and their applications in fundamental physics, astrophysics and cosmology. At the same time, we give supplementary comments as well as prospects of this emerging research direction that may help readers who are interested in entering this field.

Observational Evidence for Cosmological Coupling of Black Holes and its Implications for an Astrophysical Source of Dark Energy

“…The prevalence of strong gravitationally lensed γ-ray bursts (GRBs) has been used to estimate the comoving density of intermediate-mass BHs (IMBHs; Paynter et al 2021, see also, e.g., Wang et al 2021;Yang et al 2021;Chen et al 2022;Kalantari et al 2022;Liao et al 2022;Lin et al 2022). GRBs probe IMBHs at scales much greater than the nonlinearity scale of ∼6 Mpc, complementing ∼50 kpc MACHO constraints (Appendix B).…”

Strong gravitational lensing and microlensing of supernovae

“…Pierel et al (2022) These first few strongly lensed SNe have opened a new window to probe cosmology and supernovae through these spectacular phenomena. Two reviews (Oguri, 2019;Liao et al, 2022) on gravitationally lensed transients have illustrated the exciting utilities of lensed transients. Compared to these two reviews, we focus and dive deeper into the specific case of strongly lensed supernovae.…”

What are recent observations telling us in light of improved tests of distance duality relation?

“…From the theoretical point of view, two types of cosmological distances are usually required in developing CDDR tests, i.e., angular diameter distance D A and luminosity distance D L . For the observations of luminosity distances, many works turn to luminous sources with known (or standardizable) intrinsic luminosity in the universe like type-Ia supernova (SN Ia), while the angular diameter distances are inferred from baryon acoustic oscillations (BAO), Sunyaev-Zeldovich (SZ) effect of galaxy clusters [13][14][15], gas mass fraction measurements in galaxy clusters [16,17], and strong gravitational lensing systems [18][19][20][21]. However, it is worth noting that angular diameter distances derived from BAO is puzzled by the so-called fitting problem, which is a major challenge confronted by the standard BAO peak location with a fixed comoving ruler of about 105 h −1 Mpc [22].…”