Restriction of a character sheaf to conjugacy classes

Let A be a character sheaf on a connected reductive group G over an algebraically closed field. Assuming that the characteristic is not bad we show that for certain conjugacy classes D in G, the restriction of A to D is a local system up to shift. We also give a parametrization of unipotent cuspidal...

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Main Author: Lusztig, George
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:en_US
Published: Societatea de Ştiinţe Matematice din România 2016
Online Access:http://hdl.handle.net/1721.1/105143
https://orcid.org/0000-0001-9414-6892
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author Lusztig, George
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Lusztig, George
author_sort Lusztig, George
collection MIT
description Let A be a character sheaf on a connected reductive group G over an algebraically closed field. Assuming that the characteristic is not bad we show that for certain conjugacy classes D in G, the restriction of A to D is a local system up to shift. We also give a parametrization of unipotent cuspidal character sheaves of G in terms of restriction to conjugacy classes. Without restriction on characteristic we define canonical bijections from the set of unipotent representations of the corresponding split group over a finite field to a set combinatorially defined in terms of the Weyl group.
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spelling mit-1721.1/1051432022-10-03T09:59:22Z Restriction of a character sheaf to conjugacy classes Lusztig, George Massachusetts Institute of Technology. Department of Mathematics Lusztig, George Let A be a character sheaf on a connected reductive group G over an algebraically closed field. Assuming that the characteristic is not bad we show that for certain conjugacy classes D in G, the restriction of A to D is a local system up to shift. We also give a parametrization of unipotent cuspidal character sheaves of G in terms of restriction to conjugacy classes. Without restriction on characteristic we define canonical bijections from the set of unipotent representations of the corresponding split group over a finite field to a set combinatorially defined in terms of the Weyl group. National Science Foundation (U.S.) (Grant DMS-1303060) Simons Foundation 2016-10-28T19:08:41Z 2016-10-28T19:08:41Z 2015 Article http://purl.org/eprint/type/JournalArticle 2065-0264 1220-3874 http://hdl.handle.net/1721.1/105143 Lusztig, G. “Restriction of a character sheaf to conjugacy class.” Bulletin mathématique de la Société des Sciences Mathématiques de Roumanie 106.3 (2015): 287–309. https://orcid.org/0000-0001-9414-6892 en_US http://ssmr.ro/bulletin/volumes/58-3/node8.html Bulletin mathématique de la Société des Sciences Mathématiques de Roumanie Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Societatea de Ştiinţe Matematice din România arXiv
spellingShingle Lusztig, George
Restriction of a character sheaf to conjugacy classes
title Restriction of a character sheaf to conjugacy classes
title_full Restriction of a character sheaf to conjugacy classes
title_fullStr Restriction of a character sheaf to conjugacy classes
title_full_unstemmed Restriction of a character sheaf to conjugacy classes
title_short Restriction of a character sheaf to conjugacy classes
title_sort restriction of a character sheaf to conjugacy classes
url http://hdl.handle.net/1721.1/105143
https://orcid.org/0000-0001-9414-6892
work_keys_str_mv AT lusztiggeorge restrictionofacharactersheaftoconjugacyclasses