Speaker
Description
The large-scale structure of the Universe encodes a wealth of information about cosmology and galaxy formation. For decades, two-point correlation functions have served as a cornerstone of this effort, distilling the complex distribution of matter into powerful statistical measures. These summary statistics underpin precision constraints on the standard cosmological model and provide key insights into dark matter and dark energy.
In this talk, I will show how two-point statistics can be used as a single, powerful tool to study the Universe across a wide range of scales—from individual galaxies to massive galaxy clusters. Using data from the Hyper Suprime-Cam (HSC) survey, we map the matter distribution within these systems by constraining scaling relations that connect visible galaxies to the dark matter halos that host them, and use these results to better understand and test galaxy formation models. I will also present observational studies of the physical processes at the outer boundaries of massive X-ray galaxy clusters, where ongoing accretion and feedback influence how structures grow and evolve.
On cosmological scales, I will present results from HSC Year 3 weak-lensing analyses, focusing on key systematic effects and how they affect constraints on cosmological parameters. I will then show how cross-correlating galaxy catalogs with gravitational-wave events provides a new and independent way to measure the expansion rate of the Universe. Finally, looking ahead to the Euclid era, I will discuss how improved measurements of baryons on small scales will open a new level of precision in cosmology. Together, these studies highlight how a simple statistical measure continues to deepen our understanding of the Universe’s structure and evolution.
| Talk category | NOVA Network 1 |
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