Cartan–Helgason theorem for quaternionic symmetric and twistor spaces
Artikel i vetenskaplig tidskrift, 2024

Let (g,k) be a complex quaternionic symmetric pair with k having an ideal sl(2,ℂ), k=sl(2,ℂ)+mc. Consider the representation Sm(ℂ2)=ℂm+1 of k via the projection k→sl(2,ℂ) onto the ideal sl(2,ℂ). We study the finite dimensional irreducible representations V(λ) of g which contain Sm(ℂ2) under k⊆g. We give a characterization of all such representations V(λ) and find the corresponding multiplicity, the dimension of Hom(V(λ)|k,Sm(ℂ2)). We consider also the branching problem of V(λ) under l=u(1)ℂ+mc⊂k and find the multiplicities. Geometrically the Lie subalgebra l⊂k defines a twistor space over the compact symmetric space of the compact real form Gu of Gℂ, Lie(Gℂ)=g, and our results give the decomposition for the L2-spaces of sections of certain vector bundles over the symmetric space and line bundles over the twistor space. This generalizes Cartan–Helgason's theorem for symmetric spaces (g,k) and Schlichtkrull's theorem for Hermitian symmetric spaces where one-dimensional representations of k are considered.

Quaternionic symmetric space

Branching rule

Multiplicity

Cartan–Helgason theorem

Twistor space

Finite dimensional representations

Författare

Clemens Weiske

Chalmers, Matematiska vetenskaper, Analys och sannolikhetsteori

Jun Yu

Peking University

Genkai Zhang

Chalmers, Matematiska vetenskaper, Analys och sannolikhetsteori

Indagationes Mathematicae

0019-3577 (ISSN)

Vol. In Press

Representationer av Liegrupper. Harmonisk och komplex analys på symmetriska och lokalt symmetriska rum

Vetenskapsrådet (VR), 2019-01-01 -- 2022-12-31.

Vetenskapsrådet (VR) (2022-02861), 2023-01-01 -- 2026-12-31.

Ämneskategorier

Matematisk analys

DOI

10.1016/j.indag.2024.05.013

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Senast uppdaterat

2024-12-12