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 ${\displaystyle p=-A/\rho ^{\alpha }}$ 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.

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