Testing isotropy of cosmos with WMAP and PLANCK data

TL;DR

This paper investigates the statistical isotropy of the cosmos using WMAP and PLANCK data through the power tensor method, revealing a high degree of isotropy in recent data and revisiting previous anomalies.

Contribution

It applies the power tensor method with entropy measures to new CMB data, providing updated insights into cosmic isotropy and revisiting earlier reported anomalies.

Findings

High isotropy in WMAP 9-year data

No evidence of high-l anomalies in recent data

Method effectively detects isotropy violations

Abstract

In recent years, there have been a large number of studies which support violation of statistical isotropy. Meanwhile, there are some studies which also found inconsistency. We use the power tensor method defined earlier in the literature to study the new CMBR data. The orientation of these three orthogonal vectors, as well as the power associated with each vector, contains information about possible violation of statistical isotropy. This information is encoded in two entropy measures, the power-entropy and alignment- entropy. We apply this method to WMAP 9-year and PLANCK data. Here, we also revisit the statistics to test high-l anomaly reported in our earlier paper and find that the high degree of isotropy seen in earlier WMAP 5-year data is absent in the revised WMAP 9-year data.