2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54692Using analyticity of the vacuum wave-functional under complex scalings, the vacuum of a quantum field theory may be reconstructed from a derivative expansion valid for slowly varying fields. This enables the eigenvalue problem for the Hamiltonian to be reduced to algebraic equations. Applied to Yang-Mills theory this expansion leads to a confining force between quarks.5 pages, latex, invited talk at the Second International Sakharov Conference on Physics, May 1996High Energy Physics - Theorytext