2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/766Structure formation with topological defects is described. The main differences from inflationary models are highlighted. The results are compared with recent observations. It is concluded that all the defect models studied so far are in disagreement with recent observations of CMB anisotropies. Furthermore, present observations do not support 'decoherence', a generic feature of structure formation from topological defects.9 pages, 5 figures, moriond.styAstrophysicsHigh Energy Physics - Phenomenologytext