2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148039We examine string (vortex) formation at a quench for a weakly-coupled global U(1) theory when the excitation spectrum is non-relativistic. It is so similar to vortex production in the corresponding relativistic plasma as to reinforce arguments for the similarity of vortex production in the early universe and in low-temperature many-body physics.20 pages, RevTeX and epsf, 1 postscript figure. Resubmitted because archive (not a bulletin board) ate the figures file first time round. Available through anonymous ftp as LaTeX from ftp://euclid.tp.ph.ic.ac.uk/papers/94-5_53.tex or as LaTeX or postscript at http://euclid.tp.ph.ic.ac.uk/Papers/index.htmlHigh Energy Physics - Phenomenologytext