Colloquium on Nov. 26, 2024

Cosmic Tidal Reconstruction and Parity-Violating Mode Analysis

Speaker: Hongming Zhu (NAOC)

Venue: SWIFAR Building 2111

Time: 16:00 PM, Tuesday, Nov. 26, 2024

Abstract:

The large-scale structures of the Universe exhibit striking non-Gaussian features, often referred to as the cosmic web. The strong non-Gaussian nature of this system has traditionally limited the cosmological information that can be extracted from galaxy surveys, a phenomenon known as information saturation. In this talk, I will first show how we can recover the lost small-scale information using a nonlinear reconstruction algorithm. Then, I will discuss how we can exploit local anisotropic small-scale non-Gaussian structures to reconstruct the large-scale matter distribution. The tidal reconstruction technique can help recover the 21 cm radial modes lost due to foreground contamination. Furthermore, I will demonstrate that tidal reconstruction can probe primordial parity-violating signatures. These findings have significant implications for current and future surveys, such as DESI, PFS, CSST, and others.