Cognitive Projection and Observer Entropy: A Minimal Model of Subjective Physics

Version 11.0 of the Subjective Physics framework consolidates the computational core by integrating the minimal entropic model (v5), Σ-projection and cognitive decoherence (introduced in v8 and extended in v9), and the multi-agent extension with the Shared Reality Index (v10). The formalism is based on the projection operator Fϵ, cognitive entropy S(ϵ), and the thermodynamic trade-off functional L(ϵ), establishing a reproducible information-theoretic foundation. Numerical experiments cover entropy scaling, reaction-time distributions, adaptive thresholds, and collective multi-agent dynamics. Supplementary sections (retrodiction, weak values, EEG-inspired phase portraits, cultural variations) are provided separately as Extended Notes. This version serves as the stable reference for future theoretical and experimental studies of Subjective Physics.