学术报告—Cosmic tidal reconstruction and its applications

Abstract

The large-scale structures of the Universe exhibit striking non-Gaussian features, often described as the cosmic web. The strong non-Gaussian nature of this system has traditionally limited the cosmological information that can be extracted from a large survey. In this talk, I will discuss how we can turn this process around and exploit the local anisotropic small-scale non-Gaussian structures to reconstruct the large-scale matter distribution. These tidal reconstruction techniques can help recover the 21 cm radial modes that are lost due to foreground contamination. Furthermore, I will demonstrate that tidal reconstruction can significantly enhance the constraints on local primordial non-Gaussianity and probe the primordial parity-violating signatures. These findings have significant implications for current and future surveys such as DESI, PFS, CSST, and more.

Biography

Hongming Zhu has been a faculty member at the National Astronomical Observatories, Chinese Academy of Sciences, since August 2023. He obtained his PhD at the University of Chinese Academy of Sciences in 2017. He was a BCCP fellow at the University of California, Berkeley from 2017 to 2020 and then a CITA fellow at the Canadian Institute for Theoretical Astrophysics from 2020 to 2023. His research interests include cosmology, large-scale structure, galaxy surveys, neutrinos, and gravitational lensing.