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arXiv · 2401.14984

Projection of Elliptic Orbits and Branching Laws

Hongyu He
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Abstract

Let $G$ be a Lie group, and $H\subset G$ a closed subgroup. Let $π$ be an irreducible unitary representation of $G$. In this paper, we briefly discuss the orbit method and its application to the branching problem $π|_{H}$. We use the Gan-Gross-Prasad branching law for $(G, H)= ( U(p,q), U(p, q-1) )$ as an example to illustrate the relation between $\pro_{\f u(p, q-1)}^{\f u(p,q)} \mc O(λ)$ and the branching law of the discrete series $D_λ|_{U(p,q-1)}$ for $λ$ an regular elliptic element. We also discuss some results regarding branching laws and wave front sets. The presentation of this paper does not follow the historical timeline of development.

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Hongyu He. 2025-07-18. Projection of Elliptic Orbits and Branching Laws. https://arxiv.org/abs/2401.14984

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