Cylindrical Euler--Poisson Equation in a Chaplygin Gas Medium

We studied the Euler--Poisson equation system in the case of cylindrical symmetry with the von Neumann--Sedov--Taylor type of self-similar Ansatz and present scaling solutions. We have analyzed the scenario governed by Chaplygin's equation of state, which has historically been studied as a unifying framework of dark fluid for dark matter and dark energy.