The Hubble Constant with supernovae: Strong lensing and the 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 also will present our recent work on calibrating the absolute luminosity of Type Ia supernovae from the wide-field Zwicky Transient Facility (ZTF). 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. I'll preview the upcoming work on building this distance ladder with modern space telescopes in the JWST era. I will also 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. Finally, I'll present some ongoing work on using hierarchical Bayesian models to predict SN distances for percent precision in future H0 measurements.