The three-loop Yang-Mills condensate dark energy model and its cosmological constraints

This work is a comprehensive investigation of the Yang-Mills condensate (YMC) dark energy (DE) model, which is extended to include the three-loop quantum corrections. We study its cosmic evolution and the possibility of crossing the phantom divide w = -1, examine in detail the Hubble parameter H, the deceleration parameter q, the statefinder (r, s) diagnostic and the w - w' diagnostic for the model without and with interaction, and compare our results with other DE models. Also, using the observational data for type Ia supernovae (SNIa), the shift parameter from the cosmic microwave background (CMB), and the baryon acoustic oscillation peak from large scale structures (LSS), we give the cosmological constraints on the three-loop YMC model. It is found that the model can solve the coincidence problem naturally, and its prediction of the aforementioned parameter is much closer to the Lambda CDM (CDM: cold dark matter) model one than those from other dynamical DE models; the introduction of the matter-DE interaction will make the YMC model deviate from the Lambda CDM model, and will give an equation of state crossing -1. Moreover, it is also found that, for fitting the latest SNIa data alone, the Lambda CDM model is slightly better than the three-loop YMC model; but in fitting the combination of SNIa, CMB and LSS data, the three-loop YMC model performs better than the Lambda CDM model.