By choosing the metric (called physical metric) in general relativity as the exact solution to the Einstein equation
that fits the time delay data, one can determine the size and gravitational redshift on the surface of compact objects
(neutron stars and black holes). The author shows that the physical metric is invariant by rotation. As a result, the
frequencies of gravitational waves from pulsars are represented as n * f / for pulsar frequency f and harmonics n.
Based on this result, the author has identified potential pulsar candidates with gravitational wave spectra. This result
will be critical in the study of gravitational redshift of compact objects.
Homoclinic orbits around spinning black holes. I. Exact solution for the Kerr separatrix