Constraints on AvERA cosmologies from cosmic chronometers and type Ia supernovae

We constrain AvERA cosmologies in comparison with the flat Λ-cold dark matter (ΛCDM) model using cosmic chronometer (CC) data and the Pantheon+ sample of type Ia supernovae (SNe Ia). The analysis includes fits to both CC and SN datasets using the <ns0:monospace>dynesty</ns0:monospace> dynamic nested sampling algorithm. For the model comparison, we used the Bayesian model evidence and Anderson-Darling tests applied to the normalized residuals to assess consistency with a standard normal distribution. Best-fit parameters were derived within the redshift ranges z ≤ 2 for CCs and z ≤ 2.3 for SNe. For the baseline AvERA cosmology, we obtained best-fit values of the Hubble constant of $ H_0 = 68.32_{-3.27}^{+3.21}\,\mathrm{km\,s^{-1}\,Mpc^{-1}} $ from the CC analysis and $ H_0 = 71.99_{-1.03}^{+1.05}\,\mathrm{km\,s^{-1}\,Mpc^{-1}} $ from the SN analysis, each consistent within 1σ with the corresponding AvERA simulation value of H(z = 0). While both the CC and SN datasets yield higher Bayesian evidence for the flat ΛCDM model, they favor the AvERA cosmologies according to the Anderson-Darling test. We have identified signs of overfitting in each model, which suggests the possibility of overestimating the uncertainties in the Pantheon+ covariance matrix.