2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101941We make some remarks on the group of symmetries in gravity; we believe that K-theory and noncommutative geometry inescepably have to play an important role. Furthermore we make some comments and questions on the recent work of Connes and Kreimer on renormalisation, the Riemann-Hilbert correspondence and their relevance to quantum gravity.21 pages, tex, some clarifications on K-group actions, references addedHigh Energy Physics - Theorytext