A robust constraint on cosmic textures from the cosmic microwave background

TL;DR

This paper uses Bayesian analysis of WMAP data to test for cosmic textures, a type of topological defect, and finds no significant evidence supporting their presence, constraining their possible abundance.

Contribution

It provides a rigorous Bayesian framework to test for cosmic textures in CMB data and sets new upper limits on their abundance.

Findings

No significant detection of cosmic textures in WMAP data.

Models predicting more than 6 detectable textures are ruled out at 95% confidence.

Current data do not support extending the standard cosmological model with textures.

Abstract

Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic textures. Textures are a type of topological defect that can be produced during a cosmological phase transition in the early universe, and which leave characteristic hot and cold spots in the CMB. We apply Bayesian methods to carry out a rigorous test of the texture hypothesis, using full-sky data from the Wilkinson Microwave Anisotropy Probe. We conclude that current data do not warrant augmenting the standard cosmological model with textures. We rule out at 95% confidence models that predict more than 6 detectable cosmic textures on the full sky.