Constraining the microlensing effect on time delays with new time-delay prediction model in $H_{0}$ measurements

Understand

Time-delay strong lensing provides a unique way to directly measure the Hubble constant ($H_{0}$).

• The precision of the $H_{0}$ measurement depends on the uncertainties in the time-delay measurements, the mass distribution of the main deflector(s), and the mass distribution along the line of sight.
• Tie and Kochanek (2018) have proposed a new microlensing effect on time delays based on differential magnification of the coherent accretion disc variability of the lensed quasar.
• If real, this effect could significantly broaden the uncertainty on the time delay measurements by up to $30\%$ for lens systems such as PG1115+080, which have relatively short time delays and monitoring over several different epochs.