Novikov-type coordinates for HJ separable metrics

Synchronous frames are known to remove (at least partially) deficiencies inherent in Killing coordinates. Strangely enough, no constructive general method of finding these frames has been formulated, though it follows from the definition of synchronous coordinates; We propose here such a method and apply it to the Kerr metric to obtain a Novikov-type synchronous frame. The removal of nonphysical singularities is discussed in the context of 3-metric and 3-curvature on the spatial hypersurfaces in this frame. © 1983 Plenum Publishing Corporation.