Detecting Cosmic Strings in the CMB with the Canny Algorithm

TL;DR

This paper evaluates the effectiveness of the Canny edge detection algorithm in identifying cosmic string signatures in high-resolution CMB anisotropy maps, demonstrating improved detection limits over current bounds.

Contribution

It introduces the application of the Canny algorithm to cosmic string detection in CMB maps, showing enhanced sensitivity at high angular resolution.

Findings

Cosmic strings can be detected at lower mass per unit length than current bounds.

The Canny algorithm effectively identifies line discontinuities in simulated CMB maps.

Detection is feasible with angular resolution of several minutes of arc.

Abstract

Line discontinuities in cosmic microwave background anisotropy maps are a distinctive prediction of models with cosmic strings. These signatures are visible in anisotropy maps with good angular resolution and should be identifiable using edge detection algorithms. One such algorithm is the Canny algorithm. We study the potential of this algorithm to pick out the line discontinuities generated by cosmic strings. By applying the algorithm to small-scale microwave anisotropy maps generated from theoretical models with and without cosmic strings, we find that, given an angular resolution of several minutes of arc, cosmic strings can be detected down to a limit of the mass per unit length of the string which is one order of magnitude lower than the current upper bounds.