The evidence for association of high redshift QSOs with low redshift galaxies is subject to controversies. If it can be convincingly argued that the observed associations are accidental and could occur with reasonably high probabilities (say > 5%) then the cosmological interpretation of the redshifts of QSOs remains unaffected by the data. If, however, there is increasing evidence, either statistically or in direct physical terms, for these associations to be real, then the excess redshifts of the QSOs become anomalous. Taking the latter alternative seriously, a suggestion was made by Narlikar (Annals of Physics, 107, 325, 1977) that the anomalous redshift of the QSO in a typical QSO-galaxy pair could arise because the particle masses in the QSO were systematically smaller than those in the companion galaxy, as predicted by a theory of gravitation based on Mach's principle. One astrophysical consequence of this effect is that the QSO should appear younger than the galaxy.
Explanation of the anomalous redshift on nonlinear X-ray Compton scattering spectrum by a bound electron
