Cosmology seminar: The Hubble Constant from supernovae: Strong lensing and the local distance ladder

The Hubble tension is arguably the largest open question in modern cosmology. It could be a sign of new cosmological physics or unknown sources of systematics. To definitively answer this question, we need percent level measurements from independent cosmological probes. I will talk about strongly lensed supernovae as an exciting route to precision measurements of H0. I will review the results from our recent work estimating time-delays, extinction, and lensing magnification for the first, resolved strongly lensed Type Ia supernova, iPTF16geu and the ongoing search with ZTF. I also will present our recent work on calibrating the absolute luminosity of Type Ia supernovae from the wide-field Zwicky Transient Facility. This distance ladder is uniform in that both the calibrator and Hubble flow SNe Ia are observed with a single, untargeted survey, which sidesteps the two largest systematics in the local distance ladder, i.e. photometric cross-calibration and selection biases depending on host environment. Finally, I'll preview the upcoming work on building this distance ladder in the JWST era