The Chaplygin gas as a model for dark energy
  We review the essential features of the Chaplygin gas cosmological models and provide some examples of appearance of the Chaplygin gas equation of state in modern physics. A possible theoretical basis for the Chaplygin gas in cosmology is discussed. The relation with scalar field and tachyon cosmological models is also considered. 
V. Gorini, A. Kamenshchik, U. Moschella, V. Pasquier