English

Adapted Sequence for Polyhedral Realization of Crystal Bases

Quantum Algebra 2021-01-21 v3 Combinatorics Representation Theory

Abstract

The polyhedral realization of crystal base has been introduced by A.Zelevinsky and the second author([T.Nakashima, A.Zelevinsky, Adv. Math. 131, no. 1 (1997)]), which describe the crystal base B()B(\infty) as a polyhedral convex cone in the infinite Z\mathbb{Z}-lattice Z\mathbb{Z}^{\infty}. To construct the polyhedral realization, we need to fix an infinite sequence ι\iota from the indices of the simple roots. According to this ι\iota, one has certain set of linear functions defining a polyhedral convex cone and under the `positivity condition' on ι\iota, it has been shown that the polyhedral convex cone is isomorphic to the crystal base B()B(\infty). To confirm the positivity condition for a given ι\iota, we need to obtain the whole feature of the set of linear functions, which requires, in general, a bunch of explicit calculations. In this article, we introduce the notion of the adapted sequence and show that if ι\iota is an adapted sequence then the positivity condition holds for classical Lie algebras. Furthermore, we reveal the explicit forms of the polyhedral realizations associated with arbitrary adapted sequences ι\iota in terms of column tableaux.

Cite

@article{arxiv.1904.10919,
  title  = {Adapted Sequence for Polyhedral Realization of Crystal Bases},
  author = {Yuki Kanakubo and Toshiki Nakashima},
  journal= {arXiv preprint arXiv:1904.10919},
  year   = {2021}
}
R2 v1 2026-06-23T08:48:33.168Z