Homology rings of affine grassmannians and positively multiplicative graphs

Jérémie Guilhot, Cédric Lecouvey, Pierre Tarrago

Let $\mathfrak{g}$ be an untwisted affine Lie algebra with associated Weyl group $W_a$. To any level 0 weight $\gamma$ we associate a weighted graph ${\Gamma }_{\gamma }$ that encodes the orbit of $\gamma$…