Extremal monomial property of q-characters and polynomiality of the X-series
摘要
The character of every irreducible finite-dimensional representation of a simple Lie algebra has the highest weight property. The invariance of the character under the action of the Weyl group W implies that there is a similar “extremal weight property” for every weight obtained by applying an element of W to the highest weight. In this paper, we conjecture an analogous “extremal monomial property” of the q-characters of simple finite-dimensional modules over the quantum affine algebras, using the braid group action on q-characters defined by Chari. In the case of the identity element of W, this is the highest monomial property of q-characters proved in [