Mixed modular perverse sheaves on affine flag varieties and Koszul duality

• Simon Riche ^[1]
  1. [1] University of Clermont Auvergne

     University of Clermont Auvergne

     Arrondissement de Clermont-Ferrand, Francia

     
• Localización: Revista de la Unión Matemática Argentina, ISSN 0041-6932, ISSN-e 1669-9637, Vol. 69, Nº. 1, 2026, págs. 373-410
• Idioma: inglés
• DOI: 10.33044/revuma.5035
• Enlaces
  • Texto completo
• Resumen

  • Under some technical assumptions, and building on joint work with Bezrukavnikov, we prove a multiplicity formula for indecomposable tilting perverse sheaves on affine flag varieties, with coefficients in a field of characteristic p, in terms of p-Kazhdan–Lusztig polynomials. Under the same assumptions, we also explain the construction of a “degrading functor” relating mixed modular perverse sheaves (as defined in joint work with Achar) on such varieties to ordinary perverse sheaves.

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