Monomial realizations and LS paths of fundamental representations for rank $2$ Kac-Moody algebras

Abstract

For a Kac-Moody algebra $\mathfrak{g}$ of rank $2$ and a fundamental weight $\lambda$, we explicitly give an isomorphism between the set of Lakshmibai-Seshadri paths $\mathbb{B}(\lambda)$ and monomial realization $\mathcal{M}(\lambda)$. As an application, we also give an explicit form of monomial realization $\mathcal{M}(\lambda)$ in terms of Weyl groups.