Hironao tells about how the Hyper Suprime Cam survey collaboration have taken their own data, and the BOSS data from SDSS to do a joint cosmology constraint.

Specifically, they take the autocorrelation function of the BOSS galaxies and the cross-correlation of HSC weak lensing data with the BOSS galaxies to break degeneracies between cosmology and galaxy bias, thus allowing the full information in the galaxy data to be usable (or at least, lots more of it).

They work hard to extract information from the small scales in these two probes, using a cosmology emulator and halo occupation model, and they include various consistency tests to show that their analysis is robust. (They also did the analysis blind, to avoid human bias as much as possible).

The final constraints are comparable to recent similar DES and KiDS constraints, and consistent with both, but this analysis have a somewhat different degeneracy in the Ωm and σ8 plane.

Personally, I’d now love to see some sort of combined analysis of all three weak lensing probes as they’re all consistent with each other and I expect the combined constraints would be in a lot of tension with Planck (especially because of this different degeneracy direction).

Hironao: https://sites.google.com/view/hironaomiyatake/home

The paper: https://arxiv.org/abs/2111.02419