A proof of Lusztig's conjectures for affine type G2 with arbitrary parameters
A proof of Lusztig's conjectures for affine type G2 with arbitrary parameters
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DOI:
10.1112/plms.12211
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发表时间:
2017-11
影响因子:
1.8
通讯作者:
J. Guilhot;J. Parkinson
中科院分区:
文献类型:
--
作者:
J. Guilhot;J. Parkinson
We prove Lusztig's conjectures P1 – P15 for the affine Weyl group of type G∼2 for all choices of parameters. Our approach to compute Lusztig's a ‐function is based on the notion of a ‘balanced system of cell representations’ for the Hecke algebra. We show that for arbitrary Coxeter type the existence of balanced system of cell representations is sufficient to compute the a ‐function and we explicitly construct such a system in type G∼2 for arbitrary parameters. We then investigate the connection between Kazhdan–Lusztig cells and the Plancherel theorem in type G∼2 , allowing us to prove P1 and determine the set of Duflo involutions. From there, the proof of the remaining conjectures follows very naturally, essentially from the combinatorics of Weyl characters of types G2 and A1 , along with some explicit computations for the finite cells.