Cosmology from Cosmic Shear Power Spectra with Hyper Suprime-Cam Year 3 Data

The Hyper Suprime-Cam (HSC) survey is the deepest Stage III weak lensing experiment, going to ~26 mag in five filters with exquisite seeing. The depth and image quality achieved by HSC allow us to probe cosmology using weak lensing up to z~1.5. I will discuss our constraints on cosmological parameters using weak lensing cosmic shear power spectra measured from the Year 3 shape catalog of HSC. The shape catalog, prepared by Li et al. 2022, covers 416 square degrees of the northern sky, with a mean i-band seeing of 0.59 arcsec and an effective galaxy number density of 19.9 arcmin^-2. With an i-band magnitude limit of 24.5 mag, and four tomographic redshift bins spanning 0.3<z<1.5, we obtain a high-significance measurement of the cosmic shear power spectra in the multipole range 300<\ell<1800. I will describe our cosmological analysis, including the steps we take to prevent confirmation bias as well as our modeling of various sources of systematic uncertainties. I will then share our new constraint on the S8 parameter, and show that this constraint is robust to uncertainties in our modeling and analysis choices. Finally, I will discuss the implication of our S8 constraint in light of the apparent 2-3 sigma tension between constraints on S8 from weak lensing experiments and those from the CMB.