2009/11/30 by Jounghun Lee, Volker Springel · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2010/05/031
published as JCAP 1005:031,2010 · accepted for publication in JCAP, improved discussion, typos and minor mistakes corrected, 11 pages, 3 figures
arxiv created 2010/05/11 · openalex publication_date 2010/05/24 · arxiv updated 2010/11/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We report the finding of a scaling relation among the cosmic-web anisotropy parameter A , the linear density rms fluctuation σ( r ) and the linear growth factor D ( z ). Using the tidal field derived from the Millennium Simulation on 512 3 grids at z = 0,2,5 and 127, we calculate the largest eigenvalues λ of the local tidal tensor at each grid resolution and measure its distance-averaged two-point correlation function, ξ λ , as a function of the cosines of polar angles cos θ in the local principal axis frame. We show that ξ λ is quite anisotropic, increasing toward the directions of minimal matter compression, and that the anisotropy of ξ λ increases as the redshift z decreases and as the upper distance cutoff r c decreases. Fitting the numerical results to an analytic fitting model ξ λ (cos θ)∝(1+ A cos n θ) −1 , it is found that the best fit value of A , dubbed the cosmic-web anisotropy parameter , varies systematically with σ( r c ) and D ( z ), allowing us to determine the simple empiral scaling relation A ( r c , z ) = 0.8 D 0.76 ( z ) σ( r c ).