Discretized Weyl-orbit functions: modified multiplication and Galois symmetry

We note a remarkable similarity between the discretized Weyl-orbit functions and affine modular data associated with Wess–Zumino–Novikov–Witten (WZNW) conformal field theories. Known properties of the modular data are exploited here to uncover analogous results for the discretized orbit functions. We show that the product of orbit functions is modified in analogy with the truncation of tensor products known as affine fusion, governing the interactions in WZNW models. A Galois symmetry, like that of affine modular data, is also described for the discretized orbit functions. (paper)