Evidence of Quasi-linear Super-Structures in the Cosmic Microwave Background and Galaxy Distribution

TL;DR

This paper presents evidence of large quasi-linear super-structures in the universe, detected via the ISW effect in CMB and galaxy data, which challenge standard DM predictions and suggest the existence of supervoids or superclusters.

Contribution

A new formalism to estimate temperature fluctuations from quasi-linear structures and application to observed data revealing significant deviations from DM expectations.

Findings

Detected super-structures with radii 100-300 h^{-1}Mpc and density contrast ~0.1.

Observed ISW signals deviate from DM predictions at >3 sigma level.

Cold spot analysis suggests a large supervoid or underdensity region.

Abstract

Recent measurements of hot and cold spots on the cosmic microwave background (CMB) sky suggest a presence of super-structures on (>100 h^{-1}Mpc) scales. We develop a new formalism to estimate the expected amplitude of temperature fluctuations due to the integrated Sachs-Wolfe (ISW) effect from prominent quasi-linear structures. Applying the developed tools to the observed ISW signals from voids and clusters in catalogs of galaxies at redshifts z<1, we find that they indeed imply a presence of quasi-linear super-structures with a comoving radius 100~300 h^{-1}Mpc and a density contrast ~O(0.1). We find that the observed ISW signals are at odd with the concordant \Lambda cold dark matter (CDM) model that predicts Gaussian primordial perturbations at equal to or larger than 3 sigma level. We also confirm that the mean temperature around the CMB cold spot in the southern Galactic hemisphere filtered by a compensating top-hat filter deviates from a mean value at ~3 sigma level, implying that a quasi-linear supervoid or an underdensity region surrounded by a massive wall may reside at low redshifts z<0.3 and the actual angular size (16^\circ-17^\circ) may be larger than the apparent size (4^\circ-10^\circ) discussed in literature. Possible solutions are briefly discussed.