2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163611Consider the equivariant wave map equation from Minkowski space to a rotationnally symmetric manifold which has an equator (example: the sphere). In dimension 3, this article gives a necessary and sufficient condition for the existence of a smooth self-similar blow up profile. More generally, we study the relation between 1. the minimizing properties of the equator map for the (elliptic) Dirichlet energy and 2. the existence of a smooth blow-up profile for the (hyperbolic) wave map problem. Several applications of this approach are described.Analysis of PDEsDifferential Geometry35L70 ; 35Q80 ; 53C44 ; 58E20text