Researcher Profile and Settings

Researcher

• Name

  OOSHITA Tatsuya

Affiliation

• Mathematics Education course, Associate Professor

Profile and Settings

• Name

  Ohshita, Tatsuya

Alternate Names

• Tatsuya Ohshita

Education

• Apr. 2010, Mar. 2013
• Apr. 2008, Mar. 2010
• Apr. 2004, Mar. 2008, Kyoto University, Faculty of Science, Faculty of Science

Association Memberships

• Apr. 2020, 9999

Research Experience

• Apr. 2021, 9999, Gunma University
• Aug. 2019, Mar. 2021, Keio University, Assistant prof lv
• Aug. 2014, Jul. 2019, Ehime University, Mathematics, Physics, and Earth Sciences, Graduate School of Science and Engineering, Assistant prof lv
• Apr. 2013, Jul. 2014, Kyoto University, Researcher postdoc lv

Research Activities

Research Areas

• Natural sciences, Algebra, number theory

Research Interests

• Arithmetic Geometry
• Iwasawa theory
• ideal class groups
• Selmer group
• Euler system

Published Papers

• The Hodge realization of the polylogarithm and the Shintani generating class for totally real fields, Kenichi Bannai; Hohto Bekki; Kei Hagihara; Tatsuya Ohshita; Kazuki Yamada; Shuji Yamamoto, Jun. 2024, Advances in Mathematics, 448, 1, 74

  DOI
• Asymptotic behavior of class groups and cyclotomic Iwasawa theory of elliptic curves, Toshiro HIRANOUCHI; Tatsuya Ohshita, Oct. 2023, Journal de Theorie des Nombres de Bordeaux, 35, 2, 591, 657, Scientific journal
• ON INFINITE EXTENSIONS OF DEDEKIND DOMAINS, UPPER SEMICONTINUOUS FUNCTIONS AND THE IDEAL CLASS SEMIGROUPS, Tatsuya Ohshita, 2021, 13, 3, 407, 434, Scientific journal

  DOI
• On Higher Fitting Ideals of Certain Iwasawa Modules Associated with Galois Representations and Euler Systems, Tatsuya Ohshita, Apr. 2021, Kyoto Journal of Mathematics, 61, 1, 1, 95, Scientific journal

  DOI
• The local-global property for bitangents of plane quartics, Yasuhiro Ishituka; Tetsushi Ito; Tatsuya Ohshita; Takashi Taniguchi; Yukihiro Uchida, Jul. 2020, JSIAM Letters, 12, 0, 41, 44, Scientific journal

  DOI
• Asymptotic lower bound of class numbers along a Galois representation, Tatsuya Ohshita, Jun. 2020, Journal of Number Theory, 211, 95, 112, Scientific journal
• Explicit calculation of the mod 4 Galois representation associated with the Fermat quartic, Yasuhiro Ishitsuka; Tetsushi Ito; Tatsuya Ohshita, 2020, International Journal of Number Theory, 16, 4, 881, 905, Scientific journal
• On algorithms to obtain linear determinantal representations of smooth plane curves of higher degree, Yasuhiro Ishitsuka; Tetsushi Ito; Tatsuya Ohshita, Mar. 2019, JSIAM Letters, 11, 0, 9, 12, Scientific journal

  DOI
• On the higher Fitting ideals of Iwasawa modules of ideal class groups over real abelian fields, Tatsuya Ohshita, Feb. 2014, Journal of Number Theory, 135, 67, 138, Scientific journal

  DOI
• Higher Fitting ideals of Iwasawa modules and Euler systems, Tatsuya Ohshita, 2014, RIMS Kokyuroku Bessatsu, B51, 139, 150, Research society
• On higher fitting ideals of iwasawa modules of ideal class groups over imaginary quadratic fields and Euler systems of elliptic units, Tatsuya Ohshita, Dec. 2013, Kyoto Journal of Mathematics, 53, 4, 845, 887, Scientific journal

  DOI
• コロナ禍における海外日本人学校での教育実践 ―インターンシップとオンライン授業―, 大下達也 , 山田啓史 , 井上リカ , 井上康平 , 菅生千穂 , 伊藤隆, Mar. 2024, 41, 49, 58, Research institution
• 代数体上の楕円曲線の有理ねじれ点の位数の一様有界性について, 大下達也, 01 Feb. 2023, 271, 427
• Congruences and Prime Numbers: Practical Teaching in High School and Mathematical Backgrounds, OHSHITA, Tatsuya, 27 Jan. 2023, 71, 7, 22, Research institution
• イデアル類群の漸近挙動と楕円曲線の精Selmer群の岩澤加群について, 大下達也, Jul. 2022, 2225, 95, 111, Research society
• アーベル多様体の周期への応用, 大下達也, Apr. 2020
• 非可換岩澤主予想の証明―解析的な部分について, 大下達也, 2016, I, 401, 481
• 代数的K理論とその周辺, 井澤昇平, 大下達也, 蔦谷充伸, 野坂武史, 2013, 105, 372

MISC

• Periods modulo p of integer sequences associated with division polynomials of genus 2 curves, Yasuhiro Ishitsuka; Tetsushi Ito; Tatsuya Ohshita; Takashi Taniguchi; Yukihiro Uchida, 04 Oct. 2023, Technical report
• Euler systems for Galois deformations and the pseudo-isomorphism class of the dual of fine Selmer groups, Tatsuya Ohshita, 26 Dec. 2017, Technical report
• On higher Fitting ideals of Iwasawa modules of ideal class groups over imaginary quadratic fields and Euler systems of elliptic units II, Tatsuya Ohshita, 13 Oct. 2017, Technical report
• The arithmetic of a twist of the Fermat quartic, Yasuhiro Ishitsuka; Tetsushi Ito; Tatsuya Ohshita, 13 Jul. 2021

Presentations

• M記号係数の群コホモロジーとヘッケ作用素, 大下達也, 信州整数論小研究集会, 29 Mar. 2024, 28 Mar. 2024, 31 Mar. 2024
• Asymptotic behavior of ideal class groups and cyclotomic Iwasawa theory of elliptic curves, OHSHITA; atsuya, Seminar in Algebra and Operator Algebra, 18 Jan. 2023, 18 Jan. 2023, 18 Jan. 2023, English, Indonesia University of Education
• 幾何的ヒルベルト保型形式とダイアモンド作用素, 大下達也, Dasgupta Kakdeの最近の仕事とその周辺 Workshop, 17 Feb. 2022
• イデアル類群の漸近挙動と楕円曲線の精セルマー群の岩澤加群について, 大下達也, 代数的整数論とその周辺 2021, 14 Dec. 2021
• 代数体上の楕円曲線の有理ねじれ点の位数の一様有界性について, 大下達也, 2021年度（第28回）整数論サマースクール 「モジュラー曲線と数論」, 20 Aug. 2021
• Galois表現に沿った類数の漸近的下界について, 大下達也, 津田塾大学整数論ワークショップ 2019, 24 Nov. 2019, 23 Nov. 2019, 24 Nov. 2019
• Dedekind環の無限次拡大環の分数イデアルと上半連続関数のモノイドについて, 大下達也, 慶應義塾大学・代数セミナー, 16 Oct. 2019
• Galois 表現に沿った類数の漸近的下界について, 大下達也, 九大代数セミナー, 21 Dec. 2018
• Dedekind環の無限次拡大環の分数イデアルと上半連続関数のモノイドについて, 大下 達也, 広島大学代数セミナー, 15 Jun. 2018, Japanese
• 平面4次曲線の線形行列式表示を計算するアルゴリズムについて, 大下 達也, 日本応用数理学会2018年研究部会連合発表会 「数論アルゴリズムとその応用」(JANT)セッション, 16 Mar. 2018, Japanese, Domestic conference
• 幾何的佐武同値について, 大下 達也, 倉敷整数論集会, 22 Jul. 2016, Japanese, Domestic conference
• アーベル多様体の周期への応用, 大下 達也, 2015年度整数論サマースクール 「志村多様体とその応用」, 20 Aug. 2015, Japanese
• torsionコホモロジーの位数に関する予想, 大下 達也, 倉敷整数論集会, 02 Aug. 2015, Japanese
• Galois変形のEuler系と双対精Selmer群の擬同型類について, 大下 達也, 香川セミナー, 23 May 2015, Japanese, Domestic conference
• Euler systems for Galois deformations and pseudo-isomorphism classes of the dual fine Selmer groups, Tatsuya Ohshita, 早稲田整数論研究集会, Mar. 2015, Japanese, Domestic conference
• Galois表現のEuler系とSelmer群について, 大下 達也, 北陸数論研究集会2014「代数体の単数」, 25 Dec. 2014, Japanese, Domestic conference
• Euler systems for Galois deformations and higher Fitting ideals of the dual fine Selmer groups, Tatsuya Ohshita, 京都大学数論合同セミナー, 14 Nov. 2014, Japanese
• 非可換岩澤主予想の証明--解析的側面について, 大下 達也, 第22回（2014年度）整数論サマースクール『非可換岩澤理論』, 30 Aug. 2014, Japanese, Domestic conference
• オイラー系と岩澤加群の 高次Fitting イデアルについて, 大下 達也, 九州代数的整数論2012, 2012, Japanese, Domestic conference
• Proof of Iwasawa Main Conjecture via Euler System of cyclotomic units, 大下 達也, 岩澤理論ワークショップ2012, 2012, Japanese, Domestic conference

Research Projects

• Apr. 2014, Mar. 2018, Principal investigator, Competitive research funding
• Apr. 2020, Mar. 2024, 20K14295
• Discrete integrable systems and Diophantine problems, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), Grant-in-Aid for Challenging Research (Exploratory), Kyoto University, Jul. 2021, Mar. 2024, Coinvestigator, 21K18577
• 2010, 2012, 10J02753

Academic Contribution

• Academic society etc, 04 Nov. 2023, 04 Nov. 2023

Educational Activities

Teaching Experience

• Linear algebra II, Tokyo Institute of Technology, Dec. 2020, Mar. 2021
• linear algebra I-b, Kanagawa Institute of Technology, Apr. 2020, Aug. 2020
• Calculus II-c, Kanagawa Institute of Technology, Apr. 2020, Aug. 2020
• Oct. 2021, 9999
• Oct. 2021, 9999
• Apr. 2021, 9999
• Apr. 2021, 9999
• Apr. 2021, 9999
• Apr. 2021, 9999
• Oct. 2022, 9999

Social Contribution

Social Contribution

• オンライン授業「素数のはなし」, 11 Jan. 2023, 11 Jan. 2023, Visiting lecture　(Target:　Junior high school students, Teachers)
• Asymptotic behavior of ideal class groups and cyclotomic Iwasawa theory of elliptic curves, 18 Jan. 2023, 18 Jan. 2023, Lecture　(Target:　College students, Graduate students, Teachers, Researchers)
• General Lecture “Looking at The World of Algebra: From Theory to the Classroom”, 18 Jan. 2024, 18 Jan. 2024, Lecture　(Target:　College students, Graduate students, Teachers, Researchers)
• 教員免許状更新講習「数と式：現代代数学の視点から」, 06 Aug. 2017, 06 Aug. 2017
• 科学体験フェスティバル, 2015, 2015
• 愛媛大学オープンキャンパス（理学部）, 2017, 2017
• 群馬大学教育学研究科長期研修院（数学教育）, Apr. 2021, 9999　(Target:　Graduate students, Teachers, Researchers)
• 直角三角形と楕円曲線, 24 Sep. 2021　(Target:　Graduate students, Teachers, Researchers)
• 模擬授業「合同式と素数」, 26 Oct. 2021　(Target:　High school students)
• 数学科特別授業「素数について」, 04 Mar. 2022　(Target:　Junior high school students)
• 特別授業「余りに着目しよう」, 20 Feb. 2023, 20 Feb. 2023
• オンライン授業「素数のはなし」, 11 Jan. 2023, 11 Jan. 2023
• 聴いて、見て、実験!! たのしい金管楽器の数理, 29 Sep. 2023, 29 Sep. 2023　(Target:　Graduate students, Teachers, Researchers)