  We extract the Hubble law by the frequency-shift considerations of test
particles revolving the Kerr black hole in asymptotically de Sitter spacetime.
To this end, we take into account massive geodesic particles circularly
orbiting the Kerr-de Sitter black holes that emit redshifted photons towards a
distant observer which is moving away from the emitter-black hole system. By
considering this configuration, we obtain an expression for redshift in terms
of the spacetime parameters, such as mass, angular momentum, and the
cosmological constant. Then, we find the frequency shift of photons versus the
Hubble constant with the help of some physically motivated approximations.
Finally, some exact formulas for the Schwarzschild black hole mass and the
Hubble constant in terms of the observational redshift of massive bodies
circularly orbiting this black hole are extracted. Our results suggest a new
independent general relativistic approach to obtaining the late-time Hubble
constant in terms of observable quantities.

General Relativity and Quantum Cosmology;Cosmology and Nongalactic Astrophysics