Cosmology from weak lensing peaks and minima with Subaru Hyper Suprime-Cam survey first-year data

TL;DR

This paper uses Subaru HSC first-year weak lensing data to improve cosmological constraints by combining peak counts, minima, and power spectrum, effectively capturing non-Gaussian information and reducing uncertainties.

Contribution

It introduces a forward-modeling approach for multiple summary statistics, including peaks and minima, to enhance cosmological parameter estimation from weak lensing data.

Findings

Combined statistics yield a 35% tighter constraint on S8.

Results agree with Planck 2018 and CMB lensing studies.

Systematic effects are mitigated through targeted data cuts.

Abstract

We present cosmological constraints derived from peak counts, minimum counts, and the angular power spectrum of the Subaru Hyper Suprime-Cam first-year (HSC Y1) weak lensing shear catalog. Weak lensing peak and minimum counts contain non-Gaussian information and hence are complementary to the conventional two-point statistics in constraining cosmology. In this work, we forward-model the three summary statistics and their dependence on cosmology, using a suite of $N$-body simulations tailored to the HSC Y1 data. We investigate systematic and astrophysical effects including intrinsic alignments, baryon feedback, multiplicative bias, and photometric redshift uncertainties. We mitigate the impact of these systematics by applying cuts on angular scales, smoothing scales, statistic bins, and tomographic redshift bins. By combining peaks, minima, and the power spectrum, assuming a flat-$\Lambda$CDM model, we obtain $S_{8} \equiv \sigma_8\sqrt{\Omega_m/0.3}= 0.810^{+0.022}_{-0.026}$, a 35\% tighter constraint than that obtained from the angular power spectrum alone. Our results are in agreement with other studies using HSC weak lensing shear data, as well as with Planck 2018 cosmology and recent CMB lensing constraints from the Atacama Cosmology Telescope and the South Pole Telescope.