Can the Chaplygin gas be a plausible model for dark energy?
  In this note two cosmological models representing the flat Friedmann Universe filled with a Chaplygin fluid, with or without dust, are analyzed in terms of the recently proposed "statefinder" parameters. Trajectories of both models in the parameter plane are shown to be significantly different w.r.t. "quiessence" and "tracker" models. The generalized Chaplygin gas model with an equation of state of the form $p = -A/\rho^{\alpha}$ is also analyzed in terms of the statefinder parameters. 
Vittorio Gorini, Alexander Kamenshchik and Ugo Moschella