2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189476The consequences of level-rank duality for untwisted D-branes on an SU(N) group manifold are explored. Relations are found between the charges of D-branes (which are classified by twisted K-theory) belonging to su(N)_K and su(K)_N WZW theories, in the case of odd N+K. An isomorphism between the charge algebras is also demonstrated in this case.15 pages. v2 and v3: references added. v4: proof clarified and minor typos fixedHigh Energy Physics - Theorytext