2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82731A method using an expansion of the four-body Yakubovsky wave function components onto the basis of the Faddeev-equation solutions for the two-cluster sub-Hamiltonian eigenfunctions is proposed. This expansion reduces the Yakubovsky differential equations to a system of coupled-channel equations for functions depending on the relative coordinates between the subsystems of the two-cluster partitions. On the basis of the resulting equations the four-nucleon bound-state problem and the zero-energy n-t scattering problem are solved on the relatively small computer.LaTeX, Submitted to Physics of Atomic NucleiNuclear Theorytext