ISW Imprint of Superstructures on Linear Scales

TL;DR

This paper models the ISW imprint of supervoids and superclusters assuming linear evolution, successfully matching simulations and observations, and finds a signal slightly higher than standard cosmological predictions.

Contribution

It introduces a linear model for the ISW profile of superstructures that aligns well with simulations and observations, providing new insights into large-scale structure effects.

Findings

Model matches N-body simulations and ISW maps on large scales

Detected ISW signal at 3.2-sigma confidence level

Signal amplitude exceeds ΛCDM predictions by 2-sigma

Abstract

We build a model for the density and integrated Sachs-Wolfe (ISW) profile of supervoid and supercluster structures. Our model assumes that fluctuations evolve linearly from an initial Gaussian random field. We find these assumptions capable of describing N-body simulations and simulated ISW maps remarkably well on large scales. We construct an ISW map based on locations of superstructures identified previously in the SDSS Luminous Red Galaxy sample. A matched filter analysis of the cosmic microwave background confirms a signal at the $3.2-\sigma$ confidence level and estimates the radius of the underlying structures to be $55 \pm 28 ~h^{-1}$Mpc. The amplitude of the signal, however, is $2-\sigma$ higher than $\Lambda$CDM predictions.