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 ${\displaystyle p=-A/\rho ^{\alpha }}$, where ${\displaystyle p}$ is the pressure, ${\displaystyle \rho }$ is the density, with ${\displaystyle \alpha =1}$ and ${\displaystyle A}$ a positive constant. The substance is named after Sergey Chaplygin.

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

A slowly rotating spherically symmetric, non-viscous, self-gravitating Chapligin gas solves the Hubble tension.^[3]

See also

• Physics portal

• Dark fluid

References

1. 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, S2CID 14097770
2. 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, S2CID 119357931
3. Szigeti, Balázs Endre; Szapudi, István; Barna, Imre Ferenc; Barnaföldi, Gergely Gábor (2025). "Can Rotation Solve the Hubble Puzzle?". Monthly Notices of the Royal Astronomical Society. 538 (4): 3038–3041. arXiv:2503.13525. doi:10.1093/mnras/staf446.