Multiply lensed images of a same source experience a relative time delay in the arrival of
photons due to the path length difference and the different gravitational potentials the …

We review three distance measurement techniques beyond the local universe:(1)
gravitational lens time delays,(2) baryon acoustic oscillation (BAO), and (3) HI intensity …

We show that dark matter substructure in galaxy-scale halos perturbs the time delays
between images in strong gravitational lens systems. The variance of the effect depends on …

We use numerical simulations to test a broad range of plausible observational strategies
designed to measure the time delay between the images of gravitationally lensed quasars …

It is suspected that many strong gravitational lens galaxies lie in poor groups or rich clusters
of galaxies, which modify the lens potentials. Unfortunately, little is actually known about the …

We present a detailed strong lensing analysis of a Hubble Space Telescope/Advanced
Camera for Surveys legacy data set for the first gravitational lens, Q0957+ 561. With deep …

Quasar microlensing deals with the effect of compact objects along the line of sight on the
apparent brightness of the background quasars. Due to the relative motion between quasar …

Gravitational Microlensing can be thought of as a version of strong gravitational lensing in
which the image separation is too small to be resolved. Multiple images are formed, but their …

Recent brightness fluctuation and autocorrelation analysis of time series data and
microlensing size scales, seen in Q0957+ 561A and B, have produced important information …

Gravitational microlensing deals with the deflection of light by stellar mass objects. The
deflection angles are tiny (of the order of milliarcseconds or smaller), so that multiple images …