The axis of evil - a polarization perspective - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado

The axis of evil - a polarization perspective - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We search for an unusual alignment of the preferred axes of the quadrupoleand octopole, the so-called axis of evil, in the CMB temperature andpolarization data from WMAP. We use the part of the polarization map which isuncorrelated with the temperature map as a statistically independent probe ofthe axis of evil, which helps to assess whether the latter has a cosmologicalorigin or if is a mere chance fluctuation in the temperature. Note, though,that for certain models creating a preferred axis in the temperature map, wewould not expect to see the axis in the uncorrelated polarization map. We findthat the axis of the quadrupole of the uncorrelated polarization map roughlyaligns with the axis of evil within our measurement precision, whereas the axisof the octopole does not. However, with our measurement uncertainty, theprobability of such a scenario to happen by chance in an isotropic universe isof the order of 50 per cent. We also find that the so-called cold spot presentin the CMB temperature map is even colder in the part of the temperature mapwhich is uncorrelated with the polarization, although there is still a largeuncertainty in the latter. Therefore, our analysis of the axis of evil and afuture analysis of the cold spot in the uncorrelated temperature data willstrongly benefit from the polarization data expected from the Planck satellite.

Autor: Mona Frommert, Torsten A. Ensslin


Documentos relacionados