Chaplygin gas

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 $0<\alpha \leq 1$.

See also

• Dark fluid