The Verlinde algebra, which mathematically appears in the theory of loop groups and is related to moduli spaces of bundles over curves, turns out to be describable in terms of K-theory. This is a joint discovery with M. Hopkins and C. Teleman. Here we explain in heuristic terms how this fits naturally into ideas about the Chern-Simons topological field theory.
FREED, DANIEL S. (2001) "The Verlinde algebra is twisted equivariant K-theory," Turkish Journal of Mathematics: Vol. 25: No. 1, Article 10. Available at: https://journals.tubitak.gov.tr/math/vol25/iss1/10