Supernovae and the cosmic expansion rate: breakthroughs and challenges

Jun 02, 2022 - 11:00 am to 12:00 pm

Campus, PAB 102/103

Ariel Goobar (Stockholm University) via zoom

Zoom Recording

Cosmological distances inferred from observations of Type Ia supernovae (SNIa) over the last 30 years have provided key evidence for cosmic acceleration which led to the formulation of the very successful standard model of cosmology, Lambda-CDM. However, a failure of the model has been claimed in recent years, since the distance ladder measurement of the Hubble constant does not match the value inferred from the cosmic microwave background.  Following a personal account of lessons learned in the course of doing precision cosmology with supernovae over many years, I  will discuss possible astrophysical issues with the absolute calibration of the SNIa distance scale that need to be thoroughly examined before the need for new physics can be firmly established.