Quasi-split symmetric pairs of U(\mathfraksl_n) and Steinberg varieties of classical type

2020/02/11 by Yiqiang Li, Li, Yiqiang
Mathematics · #Advanced Algebra and Geometry #Algebraic Geometry and Number Theory #Algebraic structures and combinatorial models #FOS: Mathematics #Representation Theory (math.RT)

paper · pdf · doi:10.48550/arxiv.2002.04422

openalex publication_date 2020/02/11 · openalex created_date 2020/02/24 · openalex updated_date 2026/07/28

Abstract

We provide a Lagrangian construction for the fixed-point subalgebra, together with its idempotent form, in a quasi-split symmetric pair of type A_n-1. This is obtained inside the limit of a projective system of Borel-Moore homologies of the Steinberg varieties of n-step isotropic flag varieties. Arising from the construction are a basis of homological origin for the idempotent form and a geometric realization of rational modules.

Citations

• Cohomology for quantum groups via the geometry of the nullcone

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