A New Theory of Mass Generation Driven by Cosmic Expansion: A Conceptual Model in Which Photon Energy Lost to Cosmic Expansion Manifests as Mass, Naturally Explaining the Suppression of Primordial Black Hole Formation and the Consistency of CMB Observations

This work presents a conceptual reinterpretation of cosmic expansion and photon redshift as a continuous process of mass generation in the universe. In standard cosmology, the energy loss of photons due to redshift is treated as an apparent decrease without a clearly identified physical destination. Here, this lost energy is reinterpreted through mass–energy equivalence as a source of mass that emerges alongside cosmic expansion. Within this framework, mass is not assumed to be created only in the early universe, but is instead generated gradually over cosmological timescales. This naturally suppresses the formation of primordial black holes and remains consistent with observations of the cosmic microwave background (CMB). Using only observed CMB temperature and photon number density, the model reproduces the correct order of magnitude for the total mass of the universe. The proposed theory does not replace the standard $\Lambda$CDM model, but extends it by offering a physically intuitive interpretation of energy redistribution in an expanding universe. By relying on minimal assumptions and order-of-magnitude estimates, this work aims to stimulate discussion on the fundamental relationship between expansion, energy, and mass in cosmology.