Latest Data Constraint of Some Parameterized Dark Energy Models

Using various latest cosmological datasets including type-Ia supernovae, cosmic microwave background radiation, baryon acoustic oscillations, and estimations of the Hubble parameter, we test some dark-energy models with parameterized equations of state and try to distinguish or select observation-preferred models. We obtain the best fitting results of the six models and calculate their values of the Akaike information criteria and Bayes information criterion. We can distinguish these dark energy models from each other by using these two information criterions. However, the \varLambda CDM model remains the best fit model. Furthermore, we perform geometric diagnostics including statefinder and Om diagnostics to understand the geometric behavior of the dark energy models. We find that the six dark-energy models can be distinguished from each other and from \varLambda CDM, Chaplygin gas, quintessence models after the statefinder and Om diagnostics are performed. Finally, we consider the growth factor of the dark-energy models with comparison to the \varLambda CDM model. Still, we find the models can be distinguished from each other and from the \varLambda CDM model through the growth factor approximation.