Ellipticity of Structures in CMB Sky Maps

TL;DR

This paper investigates the ellipticity of CMB sky map contours, analyzing how resolution affects elongation measures and determining current experimental limits on distinguishing cosmological models based on curvature differences.

Contribution

It provides analytical expressions for the ellipticity of Gaussian random fields in CMB maps and assesses the sensitivity of elongation measures to experimental resolution.

Findings

Current data cannot distinguish models with curvature differences of Delta Omega_tot=0.05

Analytical formulas for ellipticity in Gaussian random fields are derived

Resolution impacts the ability to measure elongation in CMB maps

Abstract

We study the ellipticity of contour lines in the sky maps of the cosmic microwave background (CMB) as well as other measures of elongation. The sensitivity of the elongation on the resolution of the CMB maps which depends on the pixelization and the beam profile of the detector, is investigated. It is shown that the current experimental accuracy does not allow to discriminate between cosmological models which differ in curvature by Delta Omega_tot=0.05. Analytical expressions are given for the case that the statistical properties of the CMB are those of two-dimensional Gaussian random fields.