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arXiv · 1812.03033

Central morphisms and Cuspidal automorphic Representations

Jean-Pierre Labesse·Joachim Schwermer
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Abstract

Let $F$ be a global field. Let $G$ and $H$ be two connected reductive group defined over $F$ endowed with an $F$-morphism $f: H\rightarrow G$ such that the induced morphism $H_{der}\rightarrow G_{der}$ on the derived groups is a central isogeny. Our main results yield in particular the following theorem: Given any irreducible cuspidal representation $\pi$ of $G(\mathbb A_F)$ its restriction to $H(\mathbb A_F)$ contains a cuspidal representation $\sigma$ of $H(\mathbb A_F)$. Conversely, assuming moreover that $f$ is an injection, any irreducible cuspidal representation $\sigma$ of $H(\mathbb A_F)$ appears in the restriction of some cuspidal representation $\pi$ of $G(\mathbb A_F)$. This theorem has an obvious local analogue.

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Jean-Pierre Labesse, Joachim Schwermer. 2018-12-07. Central morphisms and Cuspidal automorphic Representations. https://arxiv.org/abs/1812.03033

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