Five Features of Quantum Mechanics from a Single Algebraic Structure
Jonah Brent
We show that five foundational features of quantum mechanics—complementarity, the observability of probabilities, superselection rules, the Fresnel–Arago laws, and the location of the quantum classical boundary—emerge from a single algebraic structure: the Z2 Galois grading on the representation ring of the alternating group A5. The irreducible decomposition of the unique transitive A5-permutation representation of degree 12, 12 = 1 ⊕ 3 ⊕ 5 ⊕ 3′, admits a grading induced by σ : √5 →−√5 that partitions representations into observable (V+, dim 6) and hidden (V−, dim 6) sectors. We prove that A5 is the minimal finite simple group admitting such a partition. TheHadamard product rules V− ⊙ V− ⊆ V+ and V+ ⊙V− ⊆ V− then yield: (i) complementarity as a selection rule, (ii) the observability of |ψ|2 without postulate, (iii) a Galois superselection rule for bidding cross-sector interference, (iv) the Fresnel–Arago laws (1811) as a 200-year-old experimental confirmation of this superselection rule, and (v) a per-sector action scale ℏρ derived from the graph Laplacian, with ℏτ5 = 0—interference fringes are algebraically classical. The double slit is not a quantum mystery. The paths are the mystery.
•Mar 17, 2026•0 citations