Structural Projection Cosmology v1.0: Geometry–Growth Projection Test (GGPT) as a Falsifiable Alternative to Dark Energy

We present Structural Projection Cosmology (SPC), a minimal and explicitly falsifiable framework in which cosmic acceleration is interpreted as a projection effect rather than a physical dark-energy component. The model is constructed to remain observationally degenerate with ΛCDM in the background expansion history, while predicting a systematic and unavoidable separation in the growth sector. This leads to a decisive observational criterion: Geometry alone is not sufficient. Growth reveals the structure. We define this as the Geometry–Growth Projection Test (GGPT). The framework provides a direct observational pathway to distinguish projection from physical acceleration using next-generation surveys such as Euclid, DESI, and Roman. If no separation between geometry and growth is observed, the model is ruled out.