2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162238We consider the existence problem for `Steiner networks' (trivalent graphs with 120 degree angles at each junction) in strictly convex domains, with `Neumann' boundary conditions (orthogonal intersection with the domain boundary.) For each of the three possible combinatorial possibilities, sufficient conditions on the domain are derived for existence; in addition, in each case explicit examples of nonexistence are given.submitted September 2006, accepted for journal publication November 2007Differential Geometrytext