Cosmic Chronometers in the R_h=ct Universe

Understand

The use of luminous red galaxies as cosmic chronometers provides us with an indispensable method of measuring the universal expansion rate H(z) in a model-independent way.

• Unlike many probes of the cosmological history, this approach does not rely on integrated quantities, such as the luminosity distance, and therefore does not require the pre-assumption of any particular model, which may bias subsequent interpretations of the data.
• We employ three statistical tools -- the Akaike, Kullback, and Bayes Information Criteria (AIC, KIC and BIC) -- to compare the LCDM model and the R_h=ct Universe with the currently available measurements of H(z), and show that the R_h=ct Universe is favored by these model selection criteria.
• The parameters in each model are individually optimized by maximum likelihood estimation.