2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/187143We construct all instantons for the \nlsig\ on a cylinder, known not to exist on a finite time interval. We show that the widest instantons go through sphalerons. A re-interpretation of moduli-space transforms the scale parameter $ρ$ to a boundary condition in time. This may give a handle on the $ρ\rightarrow0$ divergent instanton gas.10 pages, LaTeX, 1 figure appended (uuencoded), Leiden preprint INLO-PUB-5/94High Energy Physics - TheoryHigh Energy Physics - Latticetext