1. Percolation analysis for cosmic web with discrete points Reporter: Zhang Jiajun Supervisor: Ming-Chung Chu The Chinese University of Hong Kong Date: 2015 Nov 14th

2. Big Bang and The standard cosmology model: ΛCDM model Cosmic pie chart after Planck Big Bang and inflation  CMB with small fluctuation  Perturbation evolution with gravity  Cosmic web and us

3. N-body simulation, what do we do? Klypin, Trujillo-Gomez & Primack 2010

5. How to compare with observation? N r

6. 50 100 150 r [h -1 Mpc] 3 1 0.3 0.1 0.04 0.02 0.00 P(k) [(h -1 Mpc) 3 ] k [h/Mpc] 0.01 0.1 1 10 10 4 10 3 10 2 10 1 Eisenstein et al. ApJ 2005

7. Definition for percolation and S-bb relation Friend of Friend (FoF) bb: linking length

8. Definition for percolation and S-bb relation S: mass fraction of the largest group S bb

9. S-bb relation ΛCDM model simulated by Gadget2 IC generated using E&H powerspectrum Ω m = 0.3 Ω Λ = 0.7 Ω b = 0.024 z=0 9 realizations for N=256^3 V=500 (h^-1Mpc)^3 FOF method, S-bb relation S=N largest /N

12. SDSS The Sloan Digital Sky Survey has created the most detailed three- dimensional maps of the Universe ever made, with deep multi-color images of one third of the sky, and spectra for more than three million astronomical objects. --www.sdss.org https://www.youtube.com/channel/UCFDSMno-xnviyexzoOZBrYg

16. Probability Cloud Cluster Expansion Theory S-bb RelationCorrelation Function Not only 2 point! All high order correlation funtion! High order correlation function are different! But it’s too expansive to calculate high order correlation function. S-bb relation is cheap, easy to do!

17. Develop percolation analysis for cosmic web with discrete points, S-bb relation Propose S-bb relation as a comparison tool to tell the difference between cosmological models We find shortage of mock catalogue, fail to generate correct high order correlation function Percolation analysis: Cheap and Powerful

18. Q & A