Abstract
We construct automorphic representations for quasi-split groups G over the function field \(F=k(t)\) one of whose local components is an epipelagic representation in the sense of Reeder and Yu. We also construct the attached Galois representations under the Langlands correspondence. These Galois representations give new classes of conjecturally rigid, wildly ramified \({}^{L}{G}\)-local systems over \(\mathbb {P}^{1}-\{0,\infty \}\) that generalize the Kloosterman sheaves constructed earlier by Heinloth, Ngô and the author. We study the monodromy of these local systems and compute all examples when G is a classical group.
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Bezrukavnikov, R.: On tensor categories attached to cells in affine Weyl groups. In: Representation Theory of Algebraic Groups and Quantum Groups. Adv. Stud. Pure Math. vol. 40, pp 69–90. Mathematical Society of Japan, Tokyo (2004)
Carter, R.W.: Finite groups of Lie type. Conjugacy classes and complex characters. Pure and Applied Mathematics (New York). Wiley, New York (1985)
Deligne, P., Milne, J.S.: Tannakian categories. In: Hodge Cycles, Motives, and Shimura Varieties. Lecture Notes in Mathematics, vol. 900. Springer, Berlin (1982)
Dettweiler, M., Reiter, S.: Rigid local systems and motives of type \(G_2\). With an appendix by M. Dettweiler and N. M. Katz. Compos. Math. 146(4), 929–963 (2010)
Gaitsgory, D.: On de Jongs conjecture. Isr. J. Math. 157, 155–191 (2007)
Faltings, G.: Algebraic loop groups and moduli spaces of bundles. J. Eur. Math. Soc. 5, 41–68 (2003)
Frenkel, E., Gross, B.: A rigid irregular connection on the projective line. Ann. Math. (2) 170(3), 1469–1512 (2009)
Gaitsgory, D.: Construction of central elements in the affine Hecke algebra via nearby cycles. Invent. Math. 144(2), 253–280 (2001)
Gross, B., Levy, P., Reeder, M., Yu, J.-K.: Gradings of positive rank on simple Lie algebras. Transform. Gr. 17(4), 1123–1190 (2012)
Gross, B., Reeder, M.: Arithmetic invariants of discrete Langlands parameters. Duke Math. J. 154, 431–508 (2010)
Heinloth, J., Ngô, B.-C., Yun, Z.: Kloosterman sheaves for reductive groups. Ann. Math. (2) 177(1), 241–310 (2013)
Katz, N.M.: Gauss sums, Kloosterman sums, and monodromy groups. Annals of Mathematics Studies, vol. 116. Princeton University Press, Princeton (1988)
Lafforgue, V.: Chtoucas pour les groupes réductifs et paramétrisation de Langlands globale. arXiv:1209.5352
Lusztig, G., Spaltenstein, N.: Induced unipotent classes. J. Lond. Math. Soc. (2) 19(1), 41–52 (1979)
Lusztig, G.: A class of irreducible representations of a Weyl group. Proc. Nederl. Akad. Ser. A 82, 323–335 (1979)
Lusztig, G.: Cells in affine Weyl groups I. Algebraic groups and related topics (Kyoto/Nagoya, 1983), 255–287 Adv. Stud. Pure Math., 6, North-Holland, Amsterdam (1985)
Lusztig, G.: Cells in affine Weyl groups II. J. Algebra 109(2), 536–548 (1987)
Lusztig, G.: Cells in affine Weyl groups III. J. Fac. Sci. Univ. Tokyo Sect. IA Math. 34(2), 223–243 (1987)
Lusztig, G.: Cells in affine Weyl groups IV. J. Fac. Sci. Univ. Tokyo Sect. IA Math. 36(2), 297–328 (1989)
Lusztig, G.: Cells in affine Weyl groups and tensor categories. Adv. Math. 129(1), 85–98 (1997)
Lusztig, G.: From conjugacy classes in the Weyl group to unipotent classes. Represent. Theory 15, 494–530 (2011)
Lusztig, G.: Unipotent classes and special Weyl group representations. J. Algebra 321(11), 3418–3449 (2009)
Macdonald, I.G.: Some irreducible representations of Weyl groups. Bull. Lond. Math. Soc. 4, 148–150 (1972)
Mirković, I., Vilonen, K.: Geometric Langlands duality and representations of algebraic groups over commutative rings. Ann. Math. (2) 166(1), 95–143 (2007)
Reeder, M., Yu, J.-K.: Epipelagic representations and invariant theory. J. AMS 27, 437–477 (2014)
Springer, T.A.: Regular elements of finite reflection groups. Invent. Math. 25, 159–198 (1974)
Vinberg, E.B.: The Weyl group of a graded Lie algebra. Izv. AN SSSR. Ser. Mat. 40(3), 488–526 (1976) (in Russian); English translation: Math. USSR-Izv. bf 10, 463–495 (1976)
Yun, Z.: Global Springer theory. Adv. Math. 228(1), 266–328 (2011)
Yun, Z.: Motives with exceptional Galois groups and the inverse Galois problem. Invent. Math. 196, 267–337 (2014)
Yun, Z.: Rigidity in automorphic representations and local systems. In: Jerison, D., Kisin, M., Mrowka, T., Stanley, R., Yau, H.-T., Yau, S.-T. (eds.) Current Developments in Mathematics 2013, pp. 73–168. International Press, Somerville (2014)
Yun, Z., Zhu, X.: A monodromic geometric Satake equivalence (in preparation)
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The author thank B. Gross, M. Reeder and J-K. Yu for inspiring conversations. He also thanks an anonymous referee for useful suggestions.
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Supported by the NSF Grant DMS-1302071 and the Packard Fellowship.
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Yun, Z. Epipelagic representations and rigid local systems. Sel. Math. New Ser. 22, 1195–1243 (2016). https://doi.org/10.1007/s00029-015-0204-z
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DOI: https://doi.org/10.1007/s00029-015-0204-z