Can quantum effects on photons resolve the Hubble tension?

A cosmologist proposes that observed redshift contains two components: standard metric expansion plus a quantum contribution from photons converting energy to effective mass along their path. Fitting this hybrid model to supernova data recovers Hubble's constant at 67.4 km/s/Mpc—matching Planck's prediction and avoiding the long-standing tension with local measurements. The model also predicts consistent expansion rates across different distance ranges, suggesting potential solutions to other cosmic puzzles.