Right. In an FRW universe, one could measure the luminosity distance for several objects at different redshift, and the angular-size distance for several objects at the same redshifts, and see if they are related as expected.

]]>It’s not normally possible to measure both luminosity distances and angular diameter distances for the same source. High-redshift supernovae, for example, furnish us with luminosity distances but can’t be resolved so there’s no hope of an angular diameter distance.

]]>Probably naive question, but wouldn’t someone always test the DDR for each source separately? So not just for inhomogeneous models?

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]]>Briefly, if the gravity is a metric theory and if the Maxwell equations are valid the recipricity relation is satisfied. If you have torsion then the Maxwell equations are modified so the tgeorem no longer applies.

]]>There is no relation between the two Limas. However, J. A. S. Lima was the doctoral supervisor of R. F. L. Holanda, who is first author on the paper linked to above.

]]>Right, but the question is whether that can lead to a violation of the CCDR?

]]>The most general non-Euclidean spaces include torsion which Riemannian spaces do not.

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