Model Comparison of $Λ$CDM vs $R_h=ct$ using Cosmic Chronometers

Abstract: In 2012, Bilicki and Seikel (arXiv:1206.5130) showed that $H(z)$ data reconstructed using Gaussian Process Regression from cosmic chronometers and BAO, conclusively rules out the $R_h=ct$ model. These results were disputed by Melia and collaborators in two different works (arXiv:1304.1802 and arXiv:1802.02255), who showed using both an unbinned analysis and Gaussian Process reconstructed $H(z)$ data from chronometers, that $R_h=ct$ is favored over $\Lambda$CDM model. To resolve this imbroglio, we carry out model comparison of $\Lambda$CDM versus $R_h=ct$ by independently reproducing the above claims using latest chronometer data. We perform model selection between these two models using Bayesian model comparison. We find that no one model between $\Lambda$CDM and $R_h=ct$ is decisively favored when uniform priors on $\Lambda$CDM parameters are used. However, if we use priors centered around the Planck best-fit values, then $\Lambda$CDM is very strongly preferred over $R_h=ct$.