Speaker
Prof.
George Efstathiou
Description
I will review the evidence for a low value of S8 from cosmic shear. I will then argue that the discrepancy with the Planck value of S8 may be a caused by uncertainties in the theoretical predictions for cosmic shear arising from the modelling of the mass fluctuations on small scales. In other words, the S8 discrepancy may reflect a tension between small and large scales rather than a tension between physics at early and late times.
