English

On combinatorics of string polytopes in types $B$ and $C$

Combinatorics 2025-01-22 v2 Algebraic Geometry Representation Theory

Abstract

A string polytope is a rational convex polytope whose lattice points parametrize a highest weight crystal basis, which is obtained from a string cone by explicit affine inequalities depending on a highest weight. It also inherits geometric information of a flag variety such as toric degenerations, Newton-Okounkov bodies, mirror symmetry, Schubert calculus, and so on. In this paper, we study combinatorial properties of string polytopes in types BB and CC by giving an explicit description of string cones in these types which is analogous to Gleizer-Postnikov's description of string cones in type AA. As an application, we characterize string polytopes in type CC which are unimodularly equivalent to the Gelfand-Tsetlin polytope in type CC for a specific highest weight.

Keywords

Cite

@article{arxiv.2306.11242,
  title  = {On combinatorics of string polytopes in types $B$ and $C$},
  author = {Yunhyung Cho and Naoki Fujita and Eunjeong Lee},
  journal= {arXiv preprint arXiv:2306.11242},
  year   = {2025}
}
R2 v1 2026-06-28T11:09:12.844Z