• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Explicit computations of weight one modular forms including the cases over finite fields and their applications

Research Project

Project/Area Number 18K13394
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 11010:Algebra-related
Research InstitutionDokkyo Medical University

Principal Investigator

Ogasawara Takeshi  獨協医科大学, 医学部, 講師 (90709776)

Project Period (FY) 2018-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Keywords法pモジュラー形式 / 重さ1のモジュラー形式 / ガロア群 / 代数体 / ガロア表現
Outline of Final Research Achievements

We established a method of fast computation of weight one modular forms with prime level, including the case over finite fields, and applied it to find new examples of PGL(2,7) number fields ramified at a single prime. Also, together with G. J. Schaeffer, who had made up an effective algorithm for weight one modular forms, we found a PGL(2,7) number field ramified only at 281 with ramification index 8. Without modular form computation, it would be so difficult to discover this number field.
Furthermore, under some assumption, we gave a criterion to distinguish a type of projective image of Galois representation attached to weight one modular form over a finite field.

Academic Significance and Societal Importance of the Research Achievements

モジュラー形式は数論の研究(整数の性質を調べること)に不可欠なものとなっている。整数の性質を調べることは概して難しいものである一方、モジュラー形式の計算は多項式の計算と同じようにしてできる。本研究では、モジュラー形式を明示的に計算することで、これまで知られていなかった特徴ある整数論的対象を発見することができた。モジュラー形式の計算無しにそのような対象を発見することは困難であったと思われる。具体的な整数論的対象を発見するためにモジュラー形式の計算を応用した1つの事例を与えたことが本研究の学術的意義である。

Report

(6 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (5 results)

All 2023 2022 2020 Other

All Presentation (3 results) (of which Invited: 1 results) Remarks (2 results)

  • [Presentation] 1つの素数でのみ分岐するPGL(2,7)拡大の探索 - 重さ1の mod p モジュラー形式の計算の応用 -2023

    • Author(s)
      小笠原健
    • Organizer
      九州代数的整数論2023
    • Related Report
      2022 Annual Research Report
  • [Presentation] 1つの素数でのみ分岐するPGL(2,7)拡大の探索2022

    • Author(s)
      小笠原健
    • Organizer
      大阪大学整数論・保型形式セミナー
    • Related Report
      2022 Annual Research Report
  • [Presentation] 重さ1の mod p モジュラー形式の計算とその応用2020

    • Author(s)
      小笠原健
    • Organizer
      早稲田大学整数論セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Remarks] Takeshi OGASAWARA

    • URL

      https://sites.google.com/site/takeshiogasawarapapi/home

    • Related Report
      2020 Research-status Report
  • [Remarks] Takeshi OGASAWARA

    • URL

      https://sites.google.com/site/takeshiogasawarapapi/

    • Related Report
      2019 Research-status Report 2018 Research-status Report

URL: 

Published: 2018-04-23   Modified: 2024-01-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi