Cluster cosmology with anisotropic boosts: Validation of a novel forward modeling analysis and application on SDSS redMaPPer clusters

Kavli Affiliate: Masahiro Takada

| First 5 Authors: Youngsoo Park, Tomomi Sunayama, Masahiro Takada, Yosuke Kobayashi, Hironao Miyatake

| Summary:

We present a novel analysis for cluster cosmology that fully forward models
the abundances, weak lensing, and the clustering of galaxy clusters. Our
analysis notably includes an empirical model for the anisotropic boosts
impacting the lensing and clustering signals of optical clusters. These boosts
arise from a preferential selection of clusters surrounded by anisotropic large
scale structure, a consequence of the limited discrimination between
line-of-sight interlopers and true cluster members offered by photometric
surveys. We validate our analysis via a blind cosmology challenge on mocks, and
find that we can obtain tight and unbiased cosmological constraints without
informative priors or external calibrations on any of our model parameters. We
then apply our analysis on the SDSS redMaPPer clusters, and find results
favoring low $Omega_mathrm{m}$ and high $sigma_8$, combining to yield the
lensing strength constraint $S_8 = 0.718_{-0.015}^{+0.016}$. We investigate
potential drivers behind these results through a series of post-unblinding
tests, noting that our results are consistent with existing cluster cosmology
constraints but clearly inconsistent with other CMB/LSS based cosmology
results. From these tests, we find hints that a suppression in the cluster
lensing signal may be driving our results.

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