Bethe Equation at q=0, Möbius Inversion Formula, and Weight Multiplicities: I. sl(2) case
arXiv:math/9909056
Abstract
The U_q(\hat{sl}(2)) Bethe equation is studied at q=0. A linear congruence equation is proposed related to the string solutions. The number of its off-diagonal solutions is expressed in terms of an explicit combinatorial formula and coincides with the weight multiplicities of the quantum space.
latex2e, 35pages, no figure