Causal Structure and Single-Sign Curvature: Beyond Parameter Fitting — A Structural Signature in Cosmological Observables

This work introduces a causal-structure-based framework in which observable phenomena are interpreted as the result of constrained realizability and accumulation processes. A key result is the emergence of a single-sign curvature in cosmological observables, indicating that the observable relation maintains a consistent geometric direction across the full redshift range. This behavior arises from structural constraints rather than parameter fine-tuning, providing a robust and model-independent signature. The framework offers a new perspective for interpreting cosmological data, emphasizing geometric consistency over numerical fitting.