Cosmological Density Fluctuations on 100Mpc 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 $\Delta T \approx 10\mu K$ on the cosmic
microwave background.
