📝 SummarXiv

Abstract

We investigate non phantom tracker scalar field models as dynamical dark energy scenario. These models can alleviate the cosmic coincidence problem and transition to a cosmological constant-like behaviour at late times. Focusing on the inverse axionlike and inverse steep exponential potentials, we study their background evolution and perturbations, finding a mild suppression in the matter power spectrum compared to $\Lambda$CDM but no distinguishing features in the bispectrum. Using combined datasets of ${\rm CMB}+{\rm BAO\; (DESI~DR1\; \&\; DR2)}+{\rm Pantheon~Plus}+{\rm Hubble\; parameter}+{\rm RSD}$, we perform a statistical comparison based on the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Our results indicate that, within the framework of non-phantom tracker models, the data show no evidence for dynamical dark energy. The $\Lambda$CDM model continues to provide a better fit to current observations in the non phantom regime. We emphasise, however, that our analysis does not rule out the possibility of phantom-crossing dark energy models, which have been found in other studies to provide a better fit to some datasets.