COSMOLOGICAL DENSITY FLUCTUATIONS ON 100 Mpc SCALES AND THEIR ISW EFFECT

We measure the matter probability distribution function (PDF) via counts in cells in a volume-limited subsample of the Sloan Digital Sky Survey Luminous Red Galaxy Catalog on scales from 30 h(-1) Mpc to 150 h(-1) Mpc and estimate the linear Integrated Sachs-Wolfe effect produced by supervoids and superclusters in the tail of the PDF. We characterize the PDF by the variance, S-3, and S-4, and study in simulations the systematic effects due to finite volume, survey shape, and redshift distortion. We compare our measurement to the prediction of Lambda CDM with linear bias and find a good agreement. We use the moments to approximate the tail of the PDF with analytic functions. A simple Gaussian model for the superstructures appears to be consistent with the claim by Granett et al. that density fluctuations on 100 h(-1) Mpc scales produce hot and cold spots with Delta T approximate to 10 mu K on the cosmic microwave background.