Cosmological implications of tracker scalar fields: Testing the evidence for dynamical dark energy with recent data

We investigate nonphantom tracker scalar field models as a dynamical dark energy scenario. These models can alleviate the cosmic coincidence problem and transition to a cosmological constantlike behavior 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 $\mathrm{\ensuremath{\Lambda}}$ cold dark matter ($\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$) but no distinguishing features in the bispectrum. Using combined datasets of $\mathrm{CMB}+\mathrm{BAO}$ (DESI DR1 DR2) + Pantheon $\mathrm{Plus}+\mathrm{Hubble}$ $\mathrm{parameter}+\mathrm{RSD}$, we perform a statistical comparison based on the Akaike Information Criterion and the Bayesian Information Criterion. Our results indicate that, within the framework of nonphantom tracker models, the data show no evidence for dynamical dark energy. The $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model continues to provide a better fit to current observations in the nonphantom regime. We emphasize, 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.