Examining Photon Redshift Contributions to Galactic and Cosmic Phenomena

This study explores how photon energy loss through redshift might generate spacetime, potentially offering a fresh take on galactic rotation curves, the Tully-Fisher relation (L proportional to v^4), exponential stellar density profiles (density proportional to e^(-r/h)), galactic disk expansion, and cosmic expansion (H_0 approximately 73 km/s/Mpc), reducing reliance on dark matter and energy. Picture photons shaping spacetime: over 13.8 billion years, their energy (about 1.65 × 10^55 J per galaxy) converts via a coupling constant k_s = 6.23 × 10^ 28 m·s. Data from 20 spiral galaxies show strong fits (R^2 > 0.95, p < 0.001) for rotation velocities, growth rates, and luminosity trends within ±10% of observations. While coupling constants need deeper derivation, this approach suggests a possible alternative to ΛCDM across scales.