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arXiv · 2306.08857

On the action of the Weyl group on canonical bases

Abstract

We study representations of simply-laced Weyl groups which are equipped with canonical bases. Our main result is that for a large class of representations, the separable elements of the Weyl group $W$ act on these canonical bases by bijections up to lower-order terms. Examples of this phenomenon include the action of separable permutations on the Kazhdan--Lusztig basis of irreducible representations for the symmetric group, and the action of separable elements of $W$ on dual canonical bases of weight zero in tensor product representations of a Lie algebra. Our methods arise from categorical representation theory, and in particular the study of the perversity of Rickard complexes acting on triangulated categories.

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BibTeXRIS

Fern Gossow, Oded Yacobi. 2023-06-15. On the action of the Weyl group on canonical bases. https://arxiv.org/abs/2306.08857

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