The Hodge conjecture is a central unresolved proposition in algebraic geometry: it asserts that on complex projective algebraic varieties, all topological cohomology classes (topological “holes”) can be described by algebraic cycles (algebraic equations). Based on the PFUSRC 11-dimensional triple coaxial biconical topological unified system, this paper proposes a fundamentally new ontological judgment: the Hodge conjecture has remained unproven for nearly a century not because of a deficiency in mathematical tools, but because it has been formulated at the wrong spatial level—the 3D solidified slice—whereas its proper ontological level is the 4D flowing foundation. This paper serves as the mathematics-physics extension and capstone of PFUSRC-103: PFUSRC-103 clarified the internal topological skeleton of mathematics, establishing the Axis Unification principle and the 1-5-11 three-point topological base; this paper defines the external topological boundary of mathematics, completing the topological repositioning of the Hodge conjecture. Together, they form a complete, self-consistent closed-loop system for the mathematical topological foundation. Grounded strictly in the preceding axioms of the PFUSRC system, this paper demonstrates: the Hodge conjecture holds universally and automatically only at the 4D flowing foundation. 3D space is merely a static solidified projection slice formed by the motion of four-dimensional flow variables. Topological holes and algebraic equations are fundamentally two observational forms of the same 4D topological stress distribution at the 3D projection layer—they are naturally homologous and require no proof of equivalence. Spaces beyond four dimensions, as conventionally defined, are not independent fundamental dimensions but nested projection structures derived from the 4D foundation. Their topological legitimacy is determined by the prime convergence anchors 5 and 11 within the 55-closure system, with dimensional levels strictly following the definitions in PFUSRC-085. This paper systematically reconciles all existing mainstream mathematical results: positive partial results (such as the Lefschetz theorem and period mapping equivalence) correspond to 3D projection structures that carry complete 4D topological fingerprints; the Atiyah-Hirzebruch 3D complex manifold counterexample corresponds to artificially constructed pure 3D slices that lack 4D fingerprint anchoring, naturally severing the homologous connection between topological holes and algebraic equations. All results together support a single boundary criterion: the effective boundary of the Hodge conjecture is the interface between the 4D flowing foundation and the 3D solidified projection layer—it holds universally at the 4D foundation, and necessarily admits counterexamples at the pure 3D slice level.
Zhenmin Wang (Fri,) studied this question.