Astrophysics Colloquium: Constraining the nature of dark matter with strong gravitational lensing

Abstract: The abundance and density profiles of dark matter halos depends directly on the physics of the candidate dark matter model. Strong gravitational lensing enables a direct measurement of these properties for halos at cosmological distances, without requiring halos to contain any baryons at all and thus provides a unique and powerful way to probe the nature of dark matter. I will present our recent results using strongly lensed quasar narrow-line and warm dust emission to constrain the density profiles and mass function of dark matter halos and to provide some of the strongest constraints to date on warm-dark matter, self-interacting dark matter, and fuzzy dark matter models. I will conclude by discussing future prospects for strong gravitational lensing in the era of upcoming large surveys and the next generation of 30 meter class telescopes.