Research

Halo-Cosmic Web Relation

Dark matter halos are the bridge between observed galaxies and in matter field which are mainly invisible dark matter.

\[{\rm Matter\; Field}\quad \Leftrightarrow \quad {\rm Dark\; Matter \; Halo}\quad \Leftrightarrow \quad {\rm Galaxy}\]

Our research focus on the relation between the dark matter halo and the matter field, especially the tidal-field and the cosmic webs classified by it (T-web method). Till now, we’ve done several tests on:

• Relation between halo mass, halo formation time and local density as well as cosmic web.

• Anisotropy of the halo-web cross-correlation function under tidal field eigen-frame.

Highlights:

• (In preparation…) 3D Cosmic Web Cross-Correlation in Tidal Eigenspace I: Anisotropy of Cosmic Web-Halo Correlation and Assembly Bias Hongfei Yu, Huiyuan Wang | arXiv: 26xx.xxxxx

---

Non-Gaussianity

Precise estimation of primordial non-Gaussianity (PNG) is essential for distinguishing different inflation models and learning about primordial universe. A widely studied PNG model is called local-type $f_{\rm NL}$ which is defined as

\[\Phi = \Phi_{\rm G} + f_{\rm NL}(\Phi_{\rm G}^2 - \langle \Phi_{\rm G}^2 \rangle).\]

The current best $f_{\rm NL}$ constraint comes from the Planck experiment’s analysis of CMB, reaching $f_{\rm NL} = 0.9\pm 5.1$. Our research focus on improve the constraint from cosmic shear either by higher-order statistics nor neural network but with enough physical transparency.

Highlights: