Galaxy bias and 8 from counts in cells from the SDSS main sample

Abstract

The counts-in-cells (CIC) galaxy probability distribution depends on both the dark matter clustering amplitude 8 and the galaxy bias b. We present a theory for the CIC distribution based on a previous prescription of the underlying dark matter distribution and a linear volume transformation to redshift space. We show that, unlike the power spectrum, the CIC distribution breaks the degeneracy between 8 and b on scales large enough that both bias and redshift distortions are still linear; thus, we obtain a simultaneous fit for both parameters.We first validate the technique on the Millennium Simulation and then apply it to the Sloan Digital Sky Survey main galaxy sample. We find 8 = 0.92 .08 and b = 1.39+.11 .09 consistent with previous complementary results from redshift distortions and from Planck.