Evidence of quasi-linear super-structures in the cosmic microwave background and galaxy distribution.
INOUE K.T., SAKAI N. and TOMITA K.
Abstract (from CDS):
Recent measurements of hot and cold spots on the cosmic microwave background (CMB) sky suggest the 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 of 100 ∼ 300 h–1 Mpc and a density contrast|δ| ∼ O(0.1). We also find that the observed ISW signals are at odds with the concordant Λ cold dark matter model that predicts Gaussian primordial perturbations at ≳ 3σ level. We confirm that the mean temperature around the CMB cold spot in the southern Galactic hemisphere filtered by a compensating top-hat filter deviates from the mean value at ∼3σ 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°-17°) may be larger than the apparent size (4°-10°) discussed in literature. Possible solutions are briefly discussed.
cosmic background radiation - large-scale structure of universe