Is the CMB asymmetry due to the kinematic dipole?

TL;DR

This paper investigates whether the observed CMB parity asymmetry is related to the kinematic dipole, suggesting it may be due to residual contamination rather than fundamental physics.

Contribution

It introduces a new analysis excluding m=0 modes to study the directional properties of CMB parity asymmetry and links it to the kinematic dipole.

Findings

Preferred directions of parity parameters align with the CMB dipole.

Parity asymmetry extends up to multipole l~22.

Possible contamination from residual dipole component is suggested.

Abstract

Parity violation found in the Cosmic Microwave Background (CMB) radiation is a crucial clue for the non-standard cosmological model or the possible contamination of various foreground residuals and/or calibration of the CMB data sets. In this paper, we study the directional properties of the CMB parity asymmetry by excluding the $m=0$ modes in the definition of parity parameters. We find that the preferred directions of the parity parameters coincide with the CMB kinematic dipole, which implies that the CMB parity asymmetry may be connected with the possible contamination of the residual dipole component. We also find that such tendency is not only localized at $l=2,3$, but in the extended multipole ranges up to $l\sim 22$.