Speaker
Description
In recent years, a determination of the Hubble constant from supernovae has become increasingly discrepant with that inferred from the cosmic microwave background. This “Hubble tension” is not easily attributable to any known systematic artifacts in either measurement and may thus be indicating some new physics beyond that in the standard cosmological model. Easy fixes based on late-time modifications to the expansion rate are elusive as they require violations of the strong energy principle and even then introduce new discrepancies. One possible explanation involves a modification to the early-time expansion history of the Universe. I will discuss the Hubble tension, the difficulties with late-time solutions, these new “early dark energy” models, and their current status.
