Vol. 631
In section 3. Cosmology

Strongly lensed SNe Ia in the era of LSST: observing cadence for lens discoveries and time-delay measurements

by S. Huber et al. 2019, A&A, 631, A161

Current measurements of the Hubble constant present significant (>4 sigma) tensions between those obtained from the local distance ladder and those derived in the early Universe. The upcoming Large Synoptic Survey Telescope (LSST) will detect many strongly lensed type Ia supernovae (LSNe Ia) for time delay cosmography, which will provide direct alternative ways to measure the Hubble constant.

In this paper the authors show that using only LSST data for time-delay cosmography is not ideal, and the new telescope would be better employed as a discovery machine for LSNe Ia. This would enable time delay measurements from follow-up observations. The authors discuss the best LSST observing strategies that will provide the optimal sample of LSne Ia and which could yield an independent and extremely accurate constraint on Ho.