The Jubilee ISW Project II: observed and simulated imprints of voids and superclusters on the cosmic microwave background

TL;DR

This study investigates the ISW effect of cosmic voids and superclusters on the CMB using simulations and observational data, finding results consistent with the DM model's expectation of a negligible signal.

Contribution

It combines large-scale simulations with observational data to assess the ISW imprint of cosmic structures, confirming the DM model's prediction of a very small or zero signal.

Findings

The expected ISW signal in DM is very small and likely undetectable.

Observational data shows no significant ISW imprint, consistent with DM predictions.

Current detections of ISW effects are probably due to other phenomena.

Abstract

We examine the integrated Sachs-Wolfe (ISW) imprint of voids and superclusters on the cosmic microwave background. We first study results from the Jubilee $N$-body simulation. From Jubilee, we obtain the full-sky ISW signal from structures out to redshift $z=1.4$ and a mock luminous red galaxy (LRG) catalogue. We confirm that the expected signal in the concordance \Lambda CDM model is very small and likely to always be much smaller than the anisotropies arising at the last scattering surface. Any current detections of such an imprint must, therefore, predominantly arise from something other than an ISW effect in a \Lambda CDM universe. Using the simulation as a guide, we then look for the signal using a catalogue of voids and superclusters from the Sloan Digital Sky Survey. We find a result that is consistent with the \Lambda CDM model, i.e. a signal consistent with zero.