Large Scale Plane-Mirroring in the Cosmic Microwave Background WMAP5 Maps

TL;DR

This paper investigates large-scale plane-mirroring symmetry in WMAP5 CMB maps, finding significant symmetry at low multipoles that diminishes at higher multipoles, suggesting possible links to the Sachs-Wolfe effect or a slab-like universe topology.

Contribution

It extends previous findings of mirror symmetry in CMB maps using WMAP5 data and explores its potential cosmological implications.

Findings

Higher significance of mirror symmetry at low multipoles ( extless 5)

Symmetry disappears at higher multipoles ( extgreater 10)

Supports models involving large horizon-scale perturbations or slab topology

Abstract

We continue investigation of the hidden plane-mirror symmetry in the distribution of excursion sets in cosmic microwave background (CMB) temperature anisotropy maps, previously noticed in the three-year data of the Wilkinson microwave anisotropy probe (WMAP), using the WMAP 5 years maps. The symmetry is shown to have higher significance, \chi^2 < 1.7, for low multipoles \ell < 5, while disappearing at larger multipoles, \chi^2 > 3.5 for \ell > 10. The study of the sum and difference maps of temperature inhomogeneity regions, along with simulated maps, confirms its existence.The properties of these mirroring symmetries are compatible with those produced by the Sachs-Wolfe effect in the presence of an anomalously large component of horizon-size density perturbations, independent of one of the spatial coordinates, and/or a slab-like spatial topology of the Universe.