Fourth-Order Spectral Corrections in a Two-Plaquette SU(2) Lattice Yang–Mills Hamiltonian

ublication status: Author-reviewed preprint, Version 0.95. Not externally peer reviewed. Scope: This work concerns a finite, open two-plaquette SU(2) lattice Hamiltonian in the perturbative strong-coupling regime. Verification: Symbolic calculations and numerical diagonalization provide internal consistency checks. Independent verification of the Hamiltonian construction and perturbative coefficients remains outstanding. Originality: The underlying SU(2) representation theory and Hamiltonian perturbation methods are established mathematical techniques. The novelty of the specific assembled fourth-order coefficient has not yet been determined through a comprehensive literature comparison. Limitations: No claim is made to have established a continuum Yang–Mills mass gap or solved the Yang–Mills existence and mass-gap problem. Authorship: Daniel Ayala Feliciano.