Can anisotropy in the galaxy distribution tell the bias?

Abstract

We use information entropy to analyse the anisotropy in the mock galaxy catalogues from dark matter distribution and simulated biased galaxy distributions from cold dark matter N-body simulation. We show that one can recover the linear bias parameter of the simulated galaxy distributions by comparing the radial, polar and azimuthal anisotropies in the simulated galaxy distributions with that from the dark matter distribution. This method for determination of the linear bias requires only O(N) operations as compared to O(N2) or at least O(NlogN) operations required for the methods based on the two-point correlation function and the power spectrum. We apply this method to determine the linear bias parameter for the galaxies in the 2MASS Redshift Survey (2MRS) and find that the 2MRS galaxies in the Ks band have a linear bias of ∼1.3