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 $0 < \alpha \le 1$.

See also

• Dark fluid