Frame Rotation in the Szekeres Spacetimes

摘要: The Szekeres metric is an inhomogeneous cosmological model without any symmetries. standard Riemann-type coordinates can be transformed into spherical-type coordinates, but the no longer diagonal, and constant "radius" 2-spheres, 2-hyperboloids or 2-planes are known to "non-concentric". Since transformation dependent, we question whether these have same orientation on each 2-surface. To answer this question, set up orthonormal tetrad (ONT), investigate its variation. We find that a relative rotation of generic, it increase systematically under conditions not very restrictive. search for paths along which constant, they only exist restrictive conditions. In process, create systematic method defining ONT with chosen properties from given metric.