Cosmological constraints for the Cosmic Defect theory

TL;DR

The paper evaluates the Cosmic Defect theory against key cosmological observations, finding it performs comparably to the standard Lambda-CDM model and aligns well with data on universe age and expansion.

Contribution

It provides a comprehensive statistical analysis of the Cosmic Defect theory's parameters, demonstrating its viability as an alternative to Lambda-CDM.

Findings

Cosmic Defect theory fits observational data as well as Lambda-CDM.

The theory's parameters are consistent with universe age and Hubble constant.

The model successfully explains large scale structure and CMB acoustic scale.

Abstract

The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background acoustic scale; luminosity distances of type Ia supernovae. The test has been based on a statistical analysis of the a posteriori probabilities for three parameters of the theory. The result has been quite satisfactory and such that the performance of the theory is not distinguishable from the one of the Lambda-CDM theory. The use of the optimal values of the parameters for the calculation of the Hubble constant and the age of the universe confirms the compatibility of the Cosmic Defect approach with observations.