Old Smuggler
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This non-relativistic decomposition is arrived at by using a Newtonian approximation to calculate the "gravitational" contribution. But this approach is misguided, and inconsistent with a relativistic approach.timmdeeg said:Chodorowski (Abstract, 2011) then seemingly has criticised B&H for false reasons by stating: "We find that the resulting relation between the transported velocity and the redshift of arriving photons is not given by a relativistic Doppler formula. Instead, for small redshifts it coincides with the well known non-relativistic decomposition of the redshift into a Doppler (kinematic) component and a gravitational one." But, as you have pointed out, such a decomposition is mathematically inconsistent.
The cited statement should not be taken as a criticism of B&H, since the parallel-transport procedure Chodorowski performs is different from that referred to in B&H. That is, Chodorowski defines a "recession velocity" as the 3-velocity obtained by parallel-transporting the 4-velocity of the emitting FO along a space-like geodesic rather than along a null geodesic. This is a perfectly valid procedure to do mathematically. But then he defines the redshift obtained from this "recession velocity" as the "kinematic" part of the redshift and the remainder part of the redshift is defined as "gravitational". These definitions are very misleading, since (for small distances) the definition of "kinematic redshift" does not correspond to the redshift obtained by using SR, and the definition of "gravitational redshift" does not correspond to the effects of space-time curvature. Chodorowski should have named his spectral shift split-up in some other way, reflecting the procedure on which it is based.
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