2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/40993The theory of rare $K$ decays is reviewed, emphasizing short-distance processes and the prospects to probe the physics of flavour. A brief overview of the subject is presented, along with a more detailed discussion of the theory of $K\toπν\barν$ decays.10 pages, 3 figures, Invited Talk at KAON 2001, PisaHigh Energy Physics - Phenomenologytext