Is the cold spot responsible for the CMB North-South asymmetry?

TL;DR

This paper investigates the relationship between the CMB cold spot and the North-South asymmetry, revealing that the cold spot significantly influences the asymmetry at medium angular scales.

Contribution

It demonstrates a cause-effect link between the cold spot and the North-South asymmetry, showing the cold spot accounts for 60% of the asymmetry power at specific scales.

Findings

Cold spot diminishes lead to decreased North-South asymmetry.

Cold spot supplies 60% of the asymmetry power at l=11-20.

A cause-effect relationship is established between the two phenomena.

Abstract

Several intriguing phenomena, unlikely within the standard inflationary cosmology, were reported in the cosmic microwave background (CMB) data from WMAP and appear to be uncorrelated. Two of these phenomena, termed CMB anomalies, are representative of their disparate nature: the North-South asymmetry in the CMB angular-correlation strength, inconsistent with an isotropic universe, and the cold spot, producing a significant deviation from Gaussianity. We find a cause-effect relationship between them, at medium angular scales (l = 11 - 20): we show that a successive diminution of the cold spot (absolute-value) temperature implies a monotonic decrease of the North-South asymmetry power, and moreover we find that the cold spot supplies 60% of such power.