Speaker
Description
Gravitational lensing is a powerful tool for constraining the nature and distribution of dark matter. Strong lensing observations allow comparisons between the mass and light profiles of galaxies, and dark matter subhalos have been detected through their perturbations to lensed images. Weak lensing probes the matter power spectrum, and thus the abundance and behaviour of dark matter, as well as placing constraints on new dark matter couplings.
Matter along the line of sight in strong lens systems complicates the comparison of the mass and light profiles of galaxies. However, it also leaves a potentially measurable imprint on strong lens images. In the last decade, strong lensing has been proposed as a novel probe of cosmic shear, and thus the matter power spectrum. I will present the current status of this work: the interpretation of the line-of-sight shear, the reasons to believe this signal can be reliably measured with current and upcoming survey telescopes, the lens modelling challenges which remain as obstacles, and the anticipated power of this technique in improving dark matter constraints.