Fields of rationality of cusp forms

Abstract In this paper, we prove that for any totally real field F, weight k, and nebentypus character χ, the proportion of Hilbert cusp forms over F of weight k and character χ with bounded field of rationality approaches zero as the level grows large. This answers, in the affirmativ...

Full description

Bibliographic Details
Main Author: Binder, John
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: The Hebrew University Magnes Press 2018
Online Access:http://hdl.handle.net/1721.1/114641
_version_ 1811085688193417216
author Binder, John
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Binder, John
author_sort Binder, John
collection MIT
description Abstract In this paper, we prove that for any totally real field F, weight k, and nebentypus character χ, the proportion of Hilbert cusp forms over F of weight k and character χ with bounded field of rationality approaches zero as the level grows large. This answers, in the affirmative, a question of Serre. The proof has three main inputs: first, a lower bound on fields of rationality for admissible GL2 representations; second, an explicit computation of the (fixed-central-character) Plancherel measure for GL2; and third, a Plancherel equidistribution theorem for cusp forms with fixed central character. The equidistribution theorem is the key intermediate result and builds on earlier work of Shin and Shin–Templier and mirrors work of Finis–Lapid–Mueller by introducing an explicit bound for certain families of orbital integrals.
first_indexed 2024-09-23T13:13:23Z
format Article
id mit-1721.1/114641
institution Massachusetts Institute of Technology
language English
last_indexed 2024-09-23T13:13:23Z
publishDate 2018
publisher The Hebrew University Magnes Press
record_format dspace
spelling mit-1721.1/1146412024-06-27T19:12:32Z Fields of rationality of cusp forms Binder, John Massachusetts Institute of Technology. Department of Mathematics Abstract In this paper, we prove that for any totally real field F, weight k, and nebentypus character χ, the proportion of Hilbert cusp forms over F of weight k and character χ with bounded field of rationality approaches zero as the level grows large. This answers, in the affirmative, a question of Serre. The proof has three main inputs: first, a lower bound on fields of rationality for admissible GL2 representations; second, an explicit computation of the (fixed-central-character) Plancherel measure for GL2; and third, a Plancherel equidistribution theorem for cusp forms with fixed central character. The equidistribution theorem is the key intermediate result and builds on earlier work of Shin and Shin–Templier and mirrors work of Finis–Lapid–Mueller by introducing an explicit bound for certain families of orbital integrals. 2018-04-09T19:48:27Z 2018-04-09T19:48:27Z 2017-11 2018-02-14T04:56:47Z Article http://purl.org/eprint/type/JournalArticle 0021-2172 1565-8511 http://hdl.handle.net/1721.1/114641 Binder, John. “Fields of Rationality of Cusp Forms.” Israel Journal of Mathematics 222, no. 2 (October 2017): 973–1028. doi:10.1007/s11856-017-1610-z. en http://dx.doi.org/10.1007/s11856-017-1610-z Israel Journal of Mathematics Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Hebrew University of Jerusalem text/xml The Hebrew University Magnes Press Springer
spellingShingle Binder, John
Fields of rationality of cusp forms
title Fields of rationality of cusp forms
title_full Fields of rationality of cusp forms
title_fullStr Fields of rationality of cusp forms
title_full_unstemmed Fields of rationality of cusp forms
title_short Fields of rationality of cusp forms
title_sort fields of rationality of cusp forms
url http://hdl.handle.net/1721.1/114641
work_keys_str_mv AT binderjohn fieldsofrationalityofcuspforms