The Causal Accessibility Framework: An Interpretive Geometric Framework for Temporal Asymmetry, Causal Accessibility, and the Structure of the Block Universe

An interpretive geometric framework proposing that the arrow of time emerges from the gradient of a causal accessibility functional defined by the cosmic event horizon. The framework introduces a weighted accessibility scalar A(t) on a flat LCDM backbone, demonstrates regime-dependent thermodynamic directionality via a numerical toy model, and identifies the principal eigenvector of the causal connectivity kernel as the natural cosmological initial condition — replacing the Past Hypothesis without new physics. Includes V19 variational formulation and Python numerical code.