Anomalous parity asymmetry of WMAP 7-year power spectrum data at low multipoles: is it cosmological or systematics?

TY - JOUR

T1 - Anomalous parity asymmetry of WMAP 7-year power spectrum data at low multipoles

T2 - is it cosmological or systematics?

AU - Kim, Jaiseung

AU - Nasselski, Pavel

PY - 2010/9/1

Y1 - 2010/9/1

N2 - It is natural to assume a parity-neutral Universe and accordingly no particular parity preference in the cosmic microwave background sky. However, our investigation based on the WMAP 7-year power spectrum shows there exists a large-scale odd-parity preference with high statistical significance. We also find that the odd-parity preference in WMAP7 data is slightly higher than earlier releases. We have investigated possible origins, and ruled out various noncosmological origins. We also find that the primordial origin requires |Re[Φ(k)]||Im[Φ(k)]| for k 22/η0, where η0 is the present conformal time. In other words, it requires translational invariance in the primordial Universe to be violated on scales larger than 4Gpc. The Planck surveyor, which possesses wide frequency coverage and systematics distinct from the WMAP, may allow us to resolve the mystery of the anomalous odd-parity preference. Furthermore, polarization maps of large-sky coverage will reduce degeneracy in cosmological origins.

AB - It is natural to assume a parity-neutral Universe and accordingly no particular parity preference in the cosmic microwave background sky. However, our investigation based on the WMAP 7-year power spectrum shows there exists a large-scale odd-parity preference with high statistical significance. We also find that the odd-parity preference in WMAP7 data is slightly higher than earlier releases. We have investigated possible origins, and ruled out various noncosmological origins. We also find that the primordial origin requires |Re[Φ(k)]||Im[Φ(k)]| for k 22/η0, where η0 is the present conformal time. In other words, it requires translational invariance in the primordial Universe to be violated on scales larger than 4Gpc. The Planck surveyor, which possesses wide frequency coverage and systematics distinct from the WMAP, may allow us to resolve the mystery of the anomalous odd-parity preference. Furthermore, polarization maps of large-sky coverage will reduce degeneracy in cosmological origins.

U2 - 10.1103/PhysRevD.82.063002

DO - 10.1103/PhysRevD.82.063002

M3 - Journal article

SN - 2470-0010

VL - 82

SP - 063002

JO - Physical Review D

JF - Physical Review D

IS - 6

ER -