Deviation From \Lambda CDM With Cosmic Strings Networks

TL;DR

This paper investigates whether cosmic string networks can cause deviations from the standard b5 CDM model, using observational data to constrain the model and Bayesian analysis to compare their plausibility.

Contribution

It introduces a cosmic string network model as an alternative to b5 CDM and assesses its viability with current observational constraints.

Findings

A small non-zero contribution from cosmic strings is compatible with data.

Bayesian evidence favors the b5 CDM model over the cosmic string alternative.

Current data do not strongly support deviations from b5 CDM.

Abstract

In this work, we consider a network of cosmic strings to explain possible deviation from \Lambda CDM behaviour. We use different observational data to constrain the model and show that a small but non zero contribution from the string network is allowed by the observational data which can result in a reasonable departure from \Lambda CDM evolution. But by calculating the Bayesian Evidence, we show that the present data still strongly favour the concordance \Lambda CDM model irrespective of the choice of the prior.