A non-linear solution to the $S_8$ tension II: Analysis of DES Year 3 cosmic shear

Understand

Weak galaxy lensing surveys have consistently reported low values of the $S_8$ parameter compared to the $\textit{Planck}\ \Lambda\rm{CDM}$ cosmology.

• Amon & Efstathiou (2022) used KiDS-1000 cosmic shear measurements to propose that this tension can be reconciled if the matter fluctuation spectrum is suppressed more strongly on non-linear scales than assumed in state-of-the-art hydrodynamical simulations.
• In this paper, we investigate cosmic shear data from the Dark Energy Survey (DES) Year 3.
• The non-linear suppression of the matter power spectrum required to resolve the $S_8$ tension between DES and the $\textit{Planck}\ \Lambda\rm{CDM}$ model is not as strong as inferred using KiDS data, but is still more extreme than predictions from recent numerical simulations.