Testing the Dipole Modulation Model in CMBR

TL;DR

This paper tests the dipole modulation model explaining hemispherical power asymmetry in the CMBR and finds significant support for it in WMAP and PLANCK data, with amplitude increasing at higher multipoles.

Contribution

The study provides direct tests of the dipole modulation model in real and multipole space, confirming its predictions with observational data.

Findings

Significant dipole modulation signal in WMAP and PLANCK data.

Dipole amplitude and direction consistent with previous analyses.

Effective dipole amplitude increases with multipole l from 2 to 64.

Abstract

The hemispherical power asymmetry, observed in the CMBR data, has generally been interpreted in terms of the dipole modulation model for the temperature fluctuations. Here we point out that this model leads to several predictions, which can be directly tested in the current data. We suggest tests of the hemispherical power asymmetry both in real and multipole space. We find a significant signal of the dipole modulation model in WMAP and PLANCK data with our tests. The dipole amplitude and direction also agrees, within errors, with earlier results based on hemispherical analysis in multipole space. We also find evidence that the effective dipole modulation amplitude increases with the multipole l in the range l=2-64.