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arXiv · 2505.20134

Finite Length for Unramified $GL_2$: Beyond Multiplicity One

Lucrezia Bertoletti
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Abstract

Let $p$ be a prime number and $K$ a finite unramified extension of $\mathbb{Q}_p$. Building on recent work of Breuil, Herzig, Hu, Morra and Schraen, we study the smooth mod $p$ representations of $\mathrm{GL}_2(K)$ appearing in a tower of mod $p$ Hecke eigenspaces of the cohomology of Shimura curves, under mild genericity assumptions but notably no multiplicity one assumption at tame level, and prove that these representations are of finite length, thereby extending a previous result of the aforementioned authors.

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Lucrezia Bertoletti. 2025-05-26. Finite Length for Unramified $GL_2$: Beyond Multiplicity One. https://arxiv.org/abs/2505.20134

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