English

The twist for Richardson varieties

Representation Theory 2022-10-11 v2 Algebraic Geometry Combinatorics

Abstract

We construct the twist automorphism of open Richardson varieties inside the flag variety of a complex semisimple algebraic group. We show that the twist map preserves totally positive parts, and prove a Chamber Ansatz formula for it. Our twist map generalizes the twist maps previously constructed by Berenstein-Fomin-Zelevinsky, Marsh-Scott, and Muller-Speyer. We use it to explain the relationship between the two conjectural cluster structures for Richardson varieties studied by Leclerc and by Ingermanson.

Keywords

Cite

@article{arxiv.2204.05935,
  title  = {The twist for Richardson varieties},
  author = {Pavel Galashin and Thomas Lam},
  journal= {arXiv preprint arXiv:2204.05935},
  year   = {2022}
}

Comments

37 pages, 4 figures; v2: bibliography updates

R2 v1 2026-06-24T10:46:06.850Z