Fitting the UNION2.1 supernova sample with the R _h = ct universe

The analysis of Type Ia supernova data over the past decade has been a notable success story in cosmology. These standard candles offer us an unparalleled opportunity to study the cosmological expansion out to a redshift of 1.5. The consensus today appears to be that ΛCDM offers the best explanation for the luminosity-distance relationship seen in these events. However, a significant incompatibility is now emerging between the standard model and other equally important observations, such as those of the cosmic microwave background. ΛCDM does not provide an accurate representation of the cosmological expansion at high redshifts (z ≫ 2). It is therefore essential to re-analyze the Type Ia supernova data in light of the cosmology (the R _h = ct universe) that best represents the universe's dynamical evolution at early times. In this paper, we directly compare the distance relationship in ΛCDM with that predicted by R _h = ct, and each with the Union2.1 sample, and show that the two theories produce virtually indistinguishable profiles, though the fit with R _h = ct has not yet been optimized. This is because the data cannot be determined independently of the assumed cosmology - the supernova luminosities must be evaluated by optimizing four parameters simultaneously with those in the adopted model. This renders the data compliant to the underlying theory, so the model-dependent data reduction should not be ignored in any comparative analysis between competing cosmologies. In this paper, we use R _h = ct to fit the data reduced with ΛCDM, and though quite promising, the match is not perfect. An even better fit would result with an optimization of the data using R _h = ct from the beginning.