Dissipative generalized Chaplygin gas as phantom dark energy
  The generalized Chaplygin gas, characterized by the equation of state $p=-\mathcal{A}/\rho^{\alpha}$, has been considered as a model for dark energy due its dark-energy-like evolution at late times. When dissipative processes are taken account, within the framework of the standard Eckart theory of relativistic irreversible thermodynamics, cosmological analytical solutions are found. Using the truncated causal version of the Israel-Stewart formalism, a suitable model was constructed which cross the $w=-1$ barrier. The future-singularities encounter in both approaches are of a new type, not included in the classification presented by S. Nojiri, S. D. Odintsov and S. Tsujikawa, Phys. Rev. D71, 063004 (2005). 
Norman Cruz, Samuel Lepe, Francisco Pena