2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52192The coupled cluster method (CCM) is one of the most successful and universally applicable techniques in quantum many-body theory. The intrinsic nonlinear and non-perturbative nature of the method is considered to be one of its advantages. We present here a combination of CCM with the Wilsonian renormalization group which leads to a powerful framework for construction of effective Hamiltonian field theories. As a toy example we obtain the two-loop renormalized $ϕ^{4}$ theory.4 pages, Talk presented at the "Light Cone Workshop: Hadrons and Beyond", 5-9 August 2003, Durham, UKHigh Energy Physics - TheoryHigh Energy Physics - PhenomenologyNuclear Theorytext