Description
First Constraints from Marked Angular Power Spectra with Subaru Hyper Suprime-Cam survey first-year data
I will present the first application of marked angular power spectra to weak lensing data, using maps from the Subaru Hyper Suprime-
Cam Year 1 (HSC-Y1) survey. Marked statistics, constructed by weighting the convergence field with non-linear functions of
its smoothed version, are designed to encode higher-order information while remaining computationally tractable. We test three
mark functions that up/down-weight different density environments and evaluate their performance using simulations across 100
cosmologies. Our results show that combining marked auto- and cross-spectra improves constraints on the clustering amplitude
parameter 𝑆8 by 50% compared to standard two-point power spectra. When applied to the HSC-Y1 data, this translates into a
constraint on 𝑆8 ≡ 𝜎8√︁ Ω𝑚/0.3 = 0.808+0.023
−0.020. We assess the sensitivity of the marked power spectra to systematics including
baryonic effects, intrinsic alignment, photometric redshifts, and multiplicative shear bias, and find that appropriate choices of
smoothing scale mitigate small-scale leakage. These results demonstrate the promise of marked statistics as a practical and
powerful tool for extracting non-Gaussian information from weak lensing surveys.
