Torus fixed point sets of Hessenberg Schubert varieties in regular semisimple Hessenberg varieties
Abstract
It is well-known that the -fixed points of a Schubert variety in the flag variety can be characterized purely combinatorially in terms of Bruhat order on the symmetric group . In a recent preprint, Cho, Hong, and Lee give a combinatorial description of the -fixed points of Hessenberg analogues of Schubert varieties (which we call Hessenberg Schubert varieties) in a regular semisimple Hessenberg variety. This note gives an interpretation of their result in terms of Bruhat order by making use of a partition of the symmetric group defined using so-called subsets of Weyl type. The Appendix, written by Michael Zeng, proves a lemma concerning subsets of Weyl type which is required in our arguments.
Keywords
Cite
@article{arxiv.2112.13250,
title = {Torus fixed point sets of Hessenberg Schubert varieties in regular semisimple Hessenberg varieties},
author = {Megumi Harada and Martha Precup},
journal= {arXiv preprint arXiv:2112.13250},
year = {2022}
}
Comments
13 pages. Major revision, due to an error discovered in the proof of the main theorem of the previous version. The current version states and proves a revised result, which concerns the T-fixed points of the Hessenberg Schubert variety instead of the variety itself