Cohomology of non-generic character stacks
[Cohomologie des champs de caractères non génériques]
Journal de l’École polytechnique — Mathématiques, Tome 11 (2024), pp. 1287-1371

We study (compactly supported) cohomology of character stacks of punctured Riemann surface with prescribed semisimple local monodromies at punctures. In the case of generic local monodromies, the cohomology of these character stacks has been studied in [23, 39]. In this paper we extend the results and conjectures of [23] to the non-generic case. In particular we compute the E-series and give a conjectural formula for the mixed Poincaré series. We prove our conjecture in the case of the projective line with 4 punctures.

On étudie la cohomologie (à support compact) des champs de caractères pour les surfaces de Riemann épointées avec monodromies locales semi-simples fixées. Dans le cas de monodromies locales génériques, la cohomologie de ces champs de caractères a été étudiée dans [23, 39]. Dans cet article, on étend les résultats et la conjecture de [23] au cas non générique. En particulier, on calcule la E-série et on donne une formule conjecturale pour la série mixte de Poincaré. On démontre cette conjecture dans le cas de la droite projective privée de 4 points.

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Accepté le :
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DOI : 10.5802/jep.278
Classification : 14M35, 14D23
Keywords: Character varieties, compactly supported cohomology, moduli stacks
Mots-clés : Variétés de caractères, cohomologie à support compact, champs de modules

Scognamiglio, Tommaso  1

1 Université Paris Cité/IMJ-PRG, Campus Grands Moulins, 8 Pl. Aurélie Nemours, 75013 Paris
Licence : CC-BY 4.0
Droits d'auteur : Les auteurs conservent leurs droits
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Scognamiglio, Tommaso. Cohomology of non-generic character stacks. Journal de l’École polytechnique — Mathématiques, Tome 11 (2024), pp. 1287-1371. doi: 10.5802/jep.278

[1] Achar, Pramod N. Perverse sheaves and applications to representation theory, Math. Surveys and Monographs, 258, American Mathematical Society, Providence, RI, 2021 | DOI | MR

[2] Alper, Jarod Good moduli spaces for Artin stacks, Ann. Inst. Fourier (Grenoble), Volume 63 (2013) no. 6, pp. 2349-2402 | DOI | Numdam | Zbl | MR

[3] Behrend, Kai A. The Lefschetz trace formula for algebraic stacks, Invent. Math., Volume 112 (1993) no. 1, pp. 127-149 | DOI | Zbl | MR

[4] Boden, Hans U.; Yokogawa, Kôji Moduli spaces of parabolic Higgs bundles and parabolic K(D) pairs over smooth curves. I, Internat. J. Math., Volume 7 (1996) no. 5, pp. 573-598 | DOI | Zbl | MR

[5] Bonnafé, Cédric Mackey formula in type A, Proc. London Math. Soc. (3), Volume 80 (2000) no. 3, pp. 545-574 Corrigenda: Ibid. 86 (2003), no. 2, p. 435–442 | DOI | Zbl | MR

[6] Crawley-Boevey, William Monodromy for systems of vector bundles and multiplicative preprojective algebras, Bull. London Math. Soc., Volume 45 (2013) no. 2, pp. 309-317 | DOI | Zbl | MR

[7] Crawley-Boevey, William; Shaw, Peter Multiplicative preprojective algebras, middle convolution and the Deligne-Simpson problem, Adv. Math., Volume 201 (2006) no. 1, pp. 180-208 | DOI | Zbl | MR

[8] Davison, Ben The integrality conjecture and the cohomology of preprojective stacks, J. reine angew. Math., Volume 804 (2023), pp. 105-154 | DOI | Zbl | MR

[9] Davison, Ben; Hennecart, L.; Schlegel Mejia, S. BPS Lie algebras for totally negative 2-Calabi-Yau categories and nonabelian Hodge theory for stacks, 2022 | arXiv

[10] Davison, Ben; Meinhardt, Sven Cohomological Donaldson-Thomas theory of a quiver with potential and quantum enveloping algebras, Invent. Math., Volume 221 (2020) no. 3, pp. 777-871 | DOI | Zbl | MR

[11] Deligne, P.; Lusztig, G. Representations of reductive groups over finite fields, Ann. of Math. (2), Volume 103 (1976) no. 1, pp. 103-161 | DOI | Zbl | MR

[12] Deligne, Pierre Théorie de Hodge. III, Publ. Math. Inst. Hautes Études Sci., Volume 44 (1974), pp. 5-77 | DOI | Numdam | Zbl | MR

[13] Digne, François; Michel, Jean Representations of finite groups of Lie type, London Math. Soc. Student Texts, 95, Cambridge University Press, Cambridge, 2020 | DOI | MR

[14] Edidin, Dan; Graham, William Equivariant intersection theory, Invent. Math., Volume 131 (1998) no. 3, pp. 595-634 | DOI | MR

[15] Etingof, Pavel; Gan, Wee Liang; Oblomkov, Alexei Generalized double affine Hecke algebras of higher rank, J. reine angew. Math., Volume 600 (2006), pp. 177-201 | DOI | Zbl | MR

[16] Etingof, Pavel; Oblomkov, Alexei; Rains, Eric Generalized double affine Hecke algebras of rank 1 and quantized del Pezzo surfaces, Adv. Math., Volume 212 (2007) no. 2, pp. 749-796 | DOI | Zbl | MR

[17] Fricke, Robert; Klein, Felix Vorlesungen über die Theorie der automorphen Funktionen, 1, B. G. Teubner, Leipzig, 1912

[18] Fu, Baohua Symplectic resolutions for nilpotent orbits, Invent. Math., Volume 151 (2003) no. 1, pp. 167-186 | Zbl | DOI | MR

[19] García-Prada, O.; Gothen, P. B.; Muñoz, V. Betti numbers of the moduli space of rank 3 parabolic Higgs bundles, Mem. Amer. Math. Soc., 187, no. 879, American Mathematical Society, Providence, RI, 2007 | DOI

[20] Garsia, A. M.; Haiman, M. A remarkable q,t-Catalan sequence and q-Lagrange inversion, J. Algebraic Combin., Volume 5 (1996) no. 3, pp. 191-244 | DOI | Zbl | MR

[21] Gothen, Peter B. The Betti numbers of the moduli space of stable rank 3 Higgs bundles on a Riemann surface, Internat. J. Math., Volume 5 (1994) no. 6, pp. 861-875 | DOI | Zbl | MR

[22] Hanlon, Phil The fixed-point partition lattices, Pacific J. Math., Volume 96 (1981) no. 2, pp. 319-341 http://projecteuclid.org/euclid.pjm/1102734788 | DOI | Zbl | MR

[23] Hausel, Tamás; Letellier, Emmanuel; Rodriguez-Villegas, Fernando Arithmetic harmonic analysis on character and quiver varieties, Duke Math. J., Volume 160 (2011) no. 2, pp. 323-400 | DOI | Zbl | MR

[24] Hausel, Tamás; Letellier, Emmanuel; Rodriguez-Villegas, Fernando Arithmetic harmonic analysis on character and quiver varieties II, Adv. Math., Volume 234 (2013), pp. 85-128 | DOI | Zbl | MR

[25] Hausel, Tamás; Rodriguez-Villegas, Fernando Mixed Hodge polynomials of character varieties, Invent. Math., Volume 174 (2008) no. 3, pp. 555-624 (With an appendix by Nicholas M. Katz) | DOI | Zbl | MR

[26] Hitchin, N. J. The self-duality equations on a Riemann surface, Proc. London Math. Soc. (3), Volume 55 (1987) no. 1, pp. 59-126 | DOI | Zbl | MR

[27] Isaacs, I. Martin Character theory of finite groups, AMS Chelsea Publishing, Providence, RI, 2006 (Corrected reprint of the 1976 original) | DOI | MR

[28] King, A. D. Moduli of representations of finite-dimensional algebras, Quart. J. Math. Oxford Ser. (2), Volume 45 (1994) no. 180, pp. 515-530 | DOI | Zbl | MR

[29] Kinjo, Tasuki; Koseki, Naoki Cohomological χ-independence for Higgs bundles and Gopakumar–Vafa invariants, 2021 | arXiv

[30] Kraft, Hanspeter; Procesi, Claudio Closures of conjugacy classes of matrices are normal, Invent. Math., Volume 53 (1979) no. 3, pp. 227-247 | DOI | Zbl | MR

[31] Laszlo, Yves; Olsson, Martin The six operations for sheaves on Artin stacks. II. Adic coefficients, Publ. Math. Inst. Hautes Études Sci., Volume 107 (2008), pp. 169-210 | DOI | Numdam | Zbl | MR

[32] Lehn, Christian; Lehn, Manfred; Sorger, Christoph; van Straten, Duco Twisted cubics on cubic fourfolds, J. reine angew. Math., Volume 731 (2017), pp. 87-128 | DOI | Zbl | MR

[33] Letellier, Emmanuel Character varieties with Zariski closures of GL n -conjugacy classes at punctures, Selecta Math. (N.S.), Volume 21 (2015) no. 1, pp. 293-344 | DOI | Zbl | MR

[34] Letellier, Emmanuel DT-invariants of quivers and the Steinberg character of GL n , Internat. Math. Res. Notices (2015) no. 22, pp. 11887-11908 | Zbl | MR

[35] Letellier, Emmanuel; Rodriguez-Villegas, Fernando E-series of character varieties of non-orientable surfaces, Ann. Inst. Fourier (Grenoble), Volume 73 (2023) no. 4, pp. 1385-1420 | DOI | Zbl | MR

[36] Lusztig, G. On the finiteness of the number of unipotent classes, Invent. Math., Volume 34 (1976) no. 3, pp. 201-213 | DOI | Zbl | MR

[37] Lusztig, George; Srinivasan, Bhama The characters of the finite unitary groups, J. Algebra, Volume 49 (1977) no. 1, pp. 167-171 | DOI | Zbl | MR

[38] Macdonald, I. G. Symmetric functions and Hall polynomials, Oxford Classic Texts in the Physical Sciences, The Clarendon Press, Oxford University Press, New York, 2015

[39] Mellit, Anton Poincaré polynomials of character varieties, Macdonald polynomials and affine Springer fibers, Ann. of Math. (2), Volume 192 (2020) no. 1, pp. 165-228 | DOI | Zbl | MR

[40] Mellit, Anton Poincaré polynomials of moduli spaces of Higgs bundles and character varieties (no punctures), Invent. Math., Volume 221 (2020) no. 1, pp. 301-327 | DOI | Zbl | MR

[41] Milne, J. S. Algebraic groups. The theory of group schemes of finite type over a field, Cambridge Studies in Advanced Math., 170, Cambridge University Press, Cambridge, 2017 | DOI

[42] Mozgovoy, Sergey A computational criterion for the Kac conjecture, J. Algebra, Volume 318 (2007) no. 2, pp. 669-679 | DOI | Zbl | MR

[43] Schiffmann, Olivier Indecomposable vector bundles and stable Higgs bundles over smooth projective curves, Ann. of Math. (2), Volume 183 (2016) no. 1, pp. 297-362 | DOI | Zbl | MR

[44] Scognamiglio, Tommaso A generalization of Kac polynomials and tensor product of representations of GL n (𝔽 q ), Transform. Groups (2024) (online first, arXiv:2306.08950) | DOI

[45] Simpson, Carlos T. Harmonic bundles on noncompact curves, J. Amer. Math. Soc., Volume 3 (1990) no. 3, pp. 713-770 | DOI | Zbl | MR

[46] Springer, T. A. Linear algebraic groups, Modern Birkhäuser Classics, Birkhäuser Boston, Inc., Boston, MA, 2009

[47] Yamakawa, Daisuke Geometry of multiplicative preprojective algebra, Internat. Math. Res. Papers (2008), rpn008, 77 pages | Zbl | MR

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