An analog of theta-lifting for a curve over dual numbers over a finite field

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Authors: David Kazhdan, Alexander Polishchuk
Cited by: 0

Abstract

We continue the study of automorphic functions associated with a curve $C$ over the ring $k[\epsilon] /\left(\epsilon^2\right)$, where $k$ is a finite field, begun in [3]. More precisely, we study an example of theta-lifting in this framework and show that it can be understood in terms of the orbit decomposition of the space of automorphic functions $\mathcal{S}\left(\mathrm{SL}_2(F) \backslash \mathrm{SL}_2\left(\mathbb{A}_C\right)\right)$ introduced in [3]. We prove that all strongly cuspidal functions in $\mathcal{S}\left(\mathrm{SL}_2(F) \backslash \mathrm{SL}_2\left(\mathbb{A}_C\right)\right)$ can be constructed using theta-lifting for an appropriate double covering $\widetilde{C} \rightarrow C$.

Fields of Study & Subjects

Algebraic Geometry and Number Theory advanced mathematical theories Polynomial and algebraic computation

Publication details

Journal / source
Pure and Applied Mathematics Quarterly
Publisher
International Press of Boston
Volume
22
Issue
3
Pages
1115–1166
Publication date
1 January 2026
Language
EN