Astronomy:Chaplygin gas

Short description: Hypothetical substance used in certain cosmological theories

Chaplygin gas, 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 $0<\alpha \le 1$.

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

See also

• Dark fluid