Nature of the vorticity in the Godel spacetime

The physical meaning of the vorticity of the matter content in Godel spacetime is analyzed in some detail. As we shall see, unlike the situation in general stationary axially symmetric spacetimes (Lewis-Papapetrou), the vorticity in Godel spacetime is not associated to a circular flow of superenergy on the plane orthogonal to the vorticity vector. This fact might be at the origin of the strange behavior of gyroscopes in such spacetime. The analysis emerging from the tilted version of Godel spacetime supports further this point of view. In order to tell apart the two situations (with and without circular flow of superenergy), we introduce two different definitions of vorticity, related to the presence (absence) of such a flow. DOI: 10.1103/PhysRevD.87.087503