Article
Categorical actions on unipotent representations of finite unitary groups
Publications Mathématiques de l'IHÉS, Tome 129 (2019), pp. 129-197

Using Harish-Chandra induction and restriction, we construct a categorical action of a Kac-Moody algebra on the category of unipotent representations of finite unitary groups in non-defining characteristic. We show that the decategorified representation is naturally isomorphic to a direct sum of level 2 Fock spaces. From our construction we deduce that the Harish-Chandra branching graph coincides with the crystal graph of these Fock spaces, solving a recent conjecture of Gerber-Hiss-Jacon. We also obtain derived equivalences between blocks, yielding Broué’s abelian defect group conjecture for unipotent -blocks at linear primes .

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DOI : 10.1007/s10240-019-00104-x

Dudas, O. 1 ; Varagnolo, M. 1 ; Vasserot, E. 1

1
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     author = {Dudas, O. and Varagnolo, M. and Vasserot, E.},
     title = {Categorical actions on unipotent representations of finite unitary groups},
     journal = {Publications Math\'ematiques de l'IH\'ES},
     pages = {129--197},
     year = {2019},
     publisher = {Springer Berlin Heidelberg},
     address = {Berlin/Heidelberg},
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     doi = {10.1007/s10240-019-00104-x},
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     url = {https://www.numdam.org/articles/10.1007/s10240-019-00104-x/}
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Dudas, O.; Varagnolo, M.; Vasserot, E. Categorical actions on unipotent representations of finite unitary groups. Publications Mathématiques de l'IHÉS, Tome 129 (2019), pp. 129-197. doi: 10.1007/s10240-019-00104-x

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