2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142202Let $S_{n}$ denote the space of all $n \times n$ real symmetric matrices. For n=2 or n>2 we characterize maps F from $S_{n}$ to $S_{m}$ which preserve adjacency, i.e. if rank(A-B)=1, then rank(F(A)-F(B))=1.Latex, 20 pagesRings and AlgebrasMetric Geometry15A03, 15A04, 15A30, 15A57, 16S50, 16W10, 17A15, 17C55text