2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47006We review recent work on a new class of topological defects which possess a nonsymmetric core. They arise in scalar field theories with global symmetries, U(1) for domain walls and SU(2) for vortices, which are explicitly broken to $Z_2$ and U(1) respectively. Both of the latter symmetries are spontaneously broken. For a particular range of parameters both types of defect solutions are shown to become unstable and decay to the well known stable walls and vortices with symmetric cores.11 pages including 7 embedded postscript figures, use latex with ppeuc.sty (included). see also http://www.edu.physics.uch.gr/~leandros Talk presented at the Particle Physics and the Early Universe Conference at the University of Cambridge, 7-11 April 1997High Energy Physics - PhenomenologyAstrophysicstext