Multiply imaged time-variable sources can be used to measure absolute distances as a
function of redshifts and thus determine cosmological parameters, chiefly the Hubble …

Gravitational time delays, observed in strong lens systems where the variable background
source is multiply imaged by a massive galaxy in the foreground, provide direct …

Strong gravitational lens systems with time delays between the multiple images allow
measurements of time-delay distances, which are primarily sensitive to the Hubble constant …

Recent rapid progress in time domain surveys makes it possible to detect various types of
explosive transients in the Universe in large numbers, some of which will be gravitationally …

We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia
Data Release 2 observations following Paper III of this series. Systems include 86 confirmed …

Dual supermassive black holes (SMBHs) at∼ kiloparsec scales are the progenitor
population of SMBH mergers and play an important role in understanding the pairing and …

Galaxy mergers occur frequently in the early Universe and bring multiple supermassive
black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post …

The statistics of galactic-scale quasar pairs can elucidate our understanding of the
dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar …

We report the discovery and spectroscopic confirmation of 22 new gravitationally lensed
quasars found using Gaia data release 2. The selection was made using several …

We present our search for strong lens, galaxy-scale systems in the first data release of the
Dark Energy Survey (DES), based on a color-selected parent sample of 18 745 029 …