6–31 juil. 2026
Galileo Galilei Institute
Fuseau horaire Europe/Paris

Alternative routes to H0: time-delay cosmography with lensed SNe and the tailored expanding photosphere method for SNe II

14 juil. 2026, 11:15
1h 15m
Galileo Galilei Institute

Galileo Galilei Institute

Orateur

Stefan Taubenberger

Description

In this talk, I will present two indepent local techniques to measure the Hubble constant.
Time-delay cosmography with strongly lensed SNe has first been proposed more than 60 years ago, but has become feasible only very recently with the machine-learning aided compilation of large catalogues of strong lenses and the advent of telescopes/surveys such as Euclid, Rubin LSST, ZTF, and JWST. I will review the status of the field with a particular emphasis on the efforts by the HOLISMOKES collaboration, and focus on the exciting lensed SNe Winny and Requiem, which will provide H0 measurements with competitive errors in the near future.
Lately celebrating its 50th birthday, the expanding photosphere method for Type II SNe is barely younger than time-delay cosmography. Also this method has only become competitive in recent years thanks to computational advances and the use of spectral emulators. These allow us to replace the previously employed pre-computed dilution factors by individually optimised radiative-transfer models for every SN to infer its luminosity and distance. I will discuss the results from a pilot study based on literature data of SNe II, as well as preliminary results from the dedicated adH0cc programme.

Documents de présentation

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