High-energy photons as probes of emergent spacetime structure

We study the propagation of high-energy photons in a framework where spacetime is not a pre-existing entity but an emergent structure generated locally by mass. In this approach, photons propagate through a sequence of locally defined metrics rather than an expanding global spacetime. We show that the finite wavelength of photons leads to an energy-dependent effective coupling to spacetime structure, resulting in an energy-dependent redshift without invoking space expansion or violations of local Lorentz invariance. A natural emergent length scale is derived from the cosmological mass density, and implications for gamma-ray burst observations are discussed.