The Origin of the Universe and Space: A Unified Framework for the Evolution of Spacetime, Gravity, and Dark Energy

This paper presents Hu's Cosmic Space Origin Theory (HCSOT), a modified gravity framework that unifies spacetime, gravity, and dark energy. The model naturally resolves three major observational tensions in modern cosmology: the 5.5σ Hubble tension, the 2-3σ S8 tension, and the overabundance of massive galaxies at z > 10 observed by JWST. We parameterize the gravitational coupling function β(z) = 1 + α(1 - ρ(z)/ρ₀) and make a rigid, falsifiable prediction: the Euclid satellite will measure an 8% ± 3% enhancement in the weak lensing power spectrum at k = 0.1 h/Mpc relative to the ΛCDM model, to be tested with Euclid DR1 data in October 2026. The model introduces only one additional free parameter and provides a unified, testable solution to the most pressing challenges in cosmology.