Speaker
Description
Dark matter serves as the hidden framework shaping the universe, driving the formation, growth, and clustering of galaxies on cosmic scales. One key feature of dark matter halos, the splashback radius, represents a physical boundary that offers a more direct and fundamental description of halo structure compared to the traditional spherical overdensity approach. Using the deep, high-resolution imaging of the Hyper Suprime-Cam (HSC) survey, we can probe large-scale structures across a vast sky area. By combining weak lensing and galaxy clustering techniques, we aim to map the distribution of dark matter around massive galaxy clusters. Our study will provide the tightest constraints on the splashback radius using X-ray-selected clusters from eROSITA-eFEDS and HSC photometric galaxy data. We will then compare these results with $\Lambda$CDM predictions, contrast them with previous studies, and explore how the splashback radius can serve as a novel tool for resolving key tensions in modern cosmology.
