A plane-symmetric solution of Einstein's equations with perfect fluid and an equation of state \(p=\gamma \rho\) (Q1096899)

A new class of plane-symmetric solutions of Einstein's equations with perfect fluid source and an equation of state \(p=\gamma \rho\) \((\gamma =const.)\) is presented. It contains the static vacuum solution, a special Kasner solution and the flat Friedman-Robertson-Walker spacetime as subclasses. The only class for which the matter distribution is truly inhomogeneous represents matter concentrated around a planar orbit of the symmetry group in an expanding universe.