On the Springer correspondence for wreath products
| Autor: | Hsu, You-Hung, Lai, Chun-Ju |
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| Rok vydání: | 2024 |
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| Druh dokumentu: | Working Paper |
| Popis: | We first show that the wreath product $\Sigma_m\wr \Sigma_d$ between two symmetric groups appears as the generalized Weyl group of an Iwahori's generalized Tits system. We then introduce a certain subvariety of the flag variety of type A, and then give a geometric proof of its Bruhat decomposition indexed by $\Sigma_m\wr \Sigma_d$, via the Bialynicki-Birula decomposition. Furthermore, we realize the group algebra $\mathbb{Q}[\Sigma_m\wr \Sigma_d]$ as the top Borel-Moore homology of a Steinberg variety. Such a geometric realization leads to a Springer correspondence for the irreducible representations over $\mathbb{C}[\Sigma_m\wr \Sigma_d]$, which can be regarded as a counterpart of the Clifford theory for wreath products. Consequently, we have obtained a new Springer correspondence of type B/C/D using essentially type A geometry. Comment: 17 pages. v2: exposition improved |
| Databáze: | arXiv |
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