Balanced representations, the asymptotic Plancherel formula, and Lusztig’s conjectures for C˜2
Algebraic Combinatorics, Tome 2 (2019) no. 5, pp. 969-1031.

We prove Lusztig’s conjectures P1–P15 for the affine Weyl group of type C2 for all choices of positive weight function. Our approach to computing Lusztig’s a-function is based on the notion of a “balanced system of cell representations”. Once this system is established roughly half of the conjectures P1–P15 follow. Next we establish an “asymptotic Plancherel Theorem” for type C2, from which the remaining conjectures follow. Combined with existing results in the literature this completes the proof of Lusztig’s conjectures for all rank 1 and 2 affine Weyl groups for all choices of parameters.

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DOI : 10.5802/alco.75
Classification : 16X00
Mots-clés : Kazhdan–Lusztig theory, Plancherel formula, affine Hecke algebras
Guilhot, Jérémie 1 ; Parkinson, James 2

1 Institut Denis Poisson Université de Tours Université d’Orléans CNRS, Tours France
2 School of Mathematics and Statistics F07 University of Sydney NSW 2006, Australia
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Guilhot, Jérémie; Parkinson, James. Balanced representations, the asymptotic Plancherel formula, and Lusztig’s conjectures for $\protect \tilde{C}_2$. Algebraic Combinatorics, Tome 2 (2019) no. 5, pp. 969-1031. doi : 10.5802/alco.75. https://www.numdam.org/articles/10.5802/alco.75/

[1] Bonnafé, Cédric Semicontinuity properties of Kazhdan–Lusztig cells, N. Z. J. Math., Volume 39 (2009), pp. 171-192 | MR | Zbl

[2] Bonnafé, Cédric Kazhdan-Lusztig cells with unequal parameters, Algebra and Applications, 24, Cham: Springer, 2017, xxv + 348 pages | MR | Zbl

[3] Bonnafé, Cédric; Iancu, Lacrimioara Left cells in type Bn with unequal parameters, Represent. Theory, Volume 7 (2003), pp. 587-609 | DOI | MR | Zbl

[4] Dixmier, Jacques C*-algebras, North-Holland Mathematical Library, 15, North-Holland (Elsevier), 1983 (Transl. from the French by Francis Jellett) | Zbl

[5] Elias, Ben; Williamson, Geordie The Hodge theory of Soergel bimodules, Ann. Math. (2), Volume 180 (2014) no. 3, pp. 1089-1136 | DOI | MR | Zbl

[6] Geck, Meinolf Constructible characters, leading coefficients and left cells for finite Coxeter groups with unequal parameters, Represent. Theory, Volume 6 (2002), pp. 1-30 | DOI | MR | Zbl

[7] Geck, Meinolf Computing Kazhdan–Lusztig cells for unequal parameters, J. Algebra, Volume 281 (2004) no. 1, pp. 342-365 | DOI | MR | Zbl

[8] Geck, Meinolf On Iwahori–Hecke algebras with unequal parameters and Lusztig’s isomorphism theorem, Pure Appl. Math. Q., Volume 7 (2011) no. 3, pp. 587-620 | DOI | MR | Zbl

[9] Geck, Meinolf; Hiss, Gerhard; Lübeck, Frank; Malle, Gunter; Pfeiffer, Götz CHEVIE – A system for computing and processing generic character tables, Appl. Algebra Eng. Commun. Comput., Volume 7 (1996) no. 3, pp. 175-210 | DOI | MR | Zbl

[10] Geck, Meinolf; Pfeiffer, Götz Characters of finite Coxeter groups and Iwahori–Hecke algebras, London Mathematical Society Monographs, 21, Oxford: Clarendon Press, 2000, xv + 446 pages | MR | Zbl

[11] Görtz, Ulrich Alcove walks and nearby cycles on affine flag manifolds, J. Algebr. Comb., Volume 26 (2007) no. 4, pp. 415-430 | DOI | MR | Zbl

[12] Guilhot, Jérémie Kazhdan–Lusztig cells in affine Weyl groups of rank 2, Int. Math. Res. Not., Volume 2010 (2010) no. 17, pp. 3422-3462 | MR | Zbl

[13] Guilhot, Jérémie; Parkinson, James A proof of Lusztig’s conjectures for affine type G2 with arbitrary parameters, Proc. Lond. Math. Soc., Volume 118 (2019) no. 5, pp. 1017-1304 | DOI | Zbl

[14] Kazhdan, David; Lusztig, George Representations of Coxeter groups and Hecke algebras, Invent. Math., Volume 53 (1979) no. 2, pp. 165-184 | DOI | MR | Zbl

[15] Kazhdan, David; Lusztig, George Schubert varieties and Poincaré duality, Geometry of the Laplace operator (Proc. Symp. Pure Math.), Volume 36 (1980), pp. 185-203 (Honololu/Hawaii 1979) | DOI | Zbl

[16] Lusztig, George Left cells in Weyl groups, Lie group representations I (Lect. Notes Math.), Volume 1024 (1983), pp. 99-111 (Proc. Spec. Year, Univ. Md., College Park 1982-83) | DOI | MR | Zbl

[17] Lusztig, George Hecke algebras with unequal parameters, 18, American Mathematical Society (AMS), Providence, RI, 2003, vi + 136 pages | MR | Zbl

[18] Michel, Jean The development version of the CHEVIE package of GAP3, J. Algebra, Volume 435 (2015), pp. 308-336 | DOI | MR | Zbl

[19] Opdam, Eric M. On the spectral decomposition of affine Hecke algebras, J. Inst. Math. Jussieu, Volume 3 (2004) no. 4, pp. 531-648 | DOI | MR | Zbl

[20] Parkinson, James On calibrated representations and the Plancherel theorem for affine Hecke algebras, J. Algebr. Comb., Volume 40 (2014) no. 2, pp. 331-371 | DOI | MR | Zbl

[21] Ram, Arun Alcove walks, Hecke algebras, spherical functions, crystals and column strict tableaux, Pure Appl. Math. Q., Volume 2 (2006) no. 4, pp. 963-1013 | MR | Zbl

[22] Schönert, Martin et al. GAP – Groups, Algorithms, and Programming – version 3 release 4 patchlevel 4, 1997 (Lehrstuhl D für Mathematik, Rheinisch Westfälische Technische Hochschule, Aachen, Germany)

[23] Shi, Jian-yi; Yang, Gao The weighted universal Coxeter group and some related conjectures of Lusztig., J. Algebra, Volume 441 (2015), pp. 678-694 | MR | Zbl

[24] Xie, Xun A decomposition formula for the Kazhdan-Lusztig basis of affine Hecke algebras of rank 2 (2015) (https://arxiv.org/abs/1509.05991)

[25] Xie, Xun Conjectures P1–P15 for Coxeter groups with complete graph (2019) (https://arxiv.org/abs/1903.00078)

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