Chaplygin gas

Chaplygin gas ^[1] ,^[2] which occurs in certain theories of cosmology, is a hypothetical substance that satisfies an exotic equation of state in the form $p=-A/\rho^\alpha$ where $p$ is the pressure, $\rho$ is the density, with $\alpha=1$ and $A$ a positive constant. The substance is named after Sergey Chaplygin.

In some models, generalized Chaplygin gas is considered, where $\alpha$ is a parameter which can take on values $0 < \alpha \le 1$ .

References

^ Kamenshchik, Alexander Yu.; Moschellai, Ugo; Pasquier, Vincent (2001), "An alternative to quintessence", Phys. Lett B. 511 (2-4): 265, arXiv:gr-qc/0103004, Bibcode 2001PhLB..511..265K, doi:10.1016/S0370-2693(01)00571-8
^ Bento, M. C.; Bertolami, O.; Sen, A. A. (2002), "Generalized Chaplygin gas, accelerated expansion and dark energy-matter unification", Phys. Rev. 66 (4): 043507, arXiv:gr-qc/0202064, Bibcode 2002PhRvD..66d3507B, doi:10.1103/PhysRevD.66.043507