# A Scaling Relation of the Evolving Tidal Fields in a LCDM Cosmology - Astrophysics > Cosmology and Nongalactic Astrophysics

A Scaling Relation of the Evolving Tidal Fields in a LCDM Cosmology - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We report the finding of a scaling relation among the cosmic-web anisotropyparameter $A$, the linear density rms fluctuation sigmar and the lineargrowth factor Dz. Using the tidal field derived from the MillenniumSimulation on 512^{3} grids at z=0, 2, 5 and 127, we calculate the largesteigenvalues $\lambda$ of the local tidal tensor at each grid resolution andmeasure its distance-averaged two-point correlation function, xi {lambda}, as afunction of the cosines of polar angles costheta in the local principal axisframe. We show that xi {lambda} is quite anisotropic, increasing toward thedirections of minimal matter compression, and that the anisotropy ofxi {lambda} increases as the redshift, z, decreases and as the upper distancecutoff r {c} decreases. Fitting the numerical results to an analytic fittingmodel \xi {\lambda}\cos\theta\propto 1+A\cos^{n}\theta^{-1}, it is foundthat the best fit value of A, dubbed the cosmic-web anisotropy parameter,varies systematically with sigmar {c} and Dz, allowing us to determine thesimple empiral scaling relation Ar {c},z=0.8, D^{0.76}z, sigma r {c}$.

Author: ** Jounghun Lee Seoul Nat'l Univ., Volker Springel MPA in Garching**

Source: https://arxiv.org/