Abstract
Several combinatorial actions of the affine Weyl group of type C˜n on triangulations, trees, words and permutations are compared. Addressing a question of David Vogan, we show that, modulo a natural involution, these permutation representations are multiplicity-free. The proof uses a general construction of Gelfand subgroups in the affine Weyl groups of types C˜n and B˜n.
Original language | English |
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Pages (from-to) | 5-33 |
Number of pages | 29 |
Journal | Journal of Algebra |
Volume | 607 |
Early online date | 15 Nov 2021 |
DOIs | |
State | Published - 1 Oct 2022 |
Keywords
- Affine Weyl group
- Arc permutation
- Factorisation of the Coxeter element
- Flip
- Gelfand subgroup
- Group action
- Triangulation
All Science Journal Classification (ASJC) codes
- Algebra and Number Theory