Researchers Database

Umegaki Ichihara Yumiko

FacultyFaculty Division of Natural Sciences Research Group of Mathematics
PositionProfessor
Last Updated :2022/10/06

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Profile and Settings

  • Name (Japanese)

    Umegaki
  • Name (Kana)

    Yumiko

Research Areas

  • Natural sciences, Algebra

Research Experience

  • 2010, Mar. 2022, -:奈良女子大学理学部数学科・准教授
  • 2010, 2010, :広島大学大学院工学研究科情報工学専攻・准教授
  • 2007, 2010, :広島大学大学院工学研究科情報工学専攻・助教
  • 2003, 2007, :広島大学大学院工学研究科情報工学専攻・助手
  • 2002, 2003, :日本学術振興会特別研究員 PD
  • Apr. 2022, 9999, Nara Women's University, Faculty of Science Department of Mathematical and Physical Sciences, Professor

Education

  • 2002, Nagoya University, Japan

Association Memberships

  • 日本数学会

Ⅱ.研究活動実績

Published Papers

  • Refereed, Advanced Studies in Pure Mathematics, Bicubic number fields with large class numbers, Yasuko Morita; Atsuki Umegaki; Yumiko Umegaki, 2020, 84, 335, 351, Scientific journal
  • Refereed, Rocky Mountain Journal of Mathematics, Quartic fields with large class numbers, Atsuki Umegaki; Yumiko Umegaki, 2020, 50, 1, 267, 280, Scientific journal
  • Refereed, Journal of Number Theory, On the density function for the value-distribution of automorphic L-functions, Kohji Matsumoto; Yumiko Umegaki, 2019, 198, 176, 199, Scientific journal
  • Refereed, International Journal of Number Theory, On the value-distribution of the difference between logarithms of two symmetric power L-functions, Kohji Matsumoto; Yumiko Umegaki, Aug. 2018, 14/ 07, 2045, 2081, Scientific journal
  • Refereed, JOURNAL OF NUMBER THEORY, ACADEMIC PRESS INC ELSEVIER SCIENCE, The first moment of L-functions of primitive forms on Gamma(0)(p(alpha)) and a basis of old forms, Yumiko Ichihara, We consider the first moment of. the value of automorphic L-functions at an arbitrary point on the critical line, a sum over primitive forms weighted by their Petersson's norm. In this paper, we obtain an asymptotic formula for it when weight k is an even integer satisfying 0 < k < 12 or k = 14 and level is p(alpha), where p is a prime number. This formula yields a lower bound of the number of primitive forms, whose L-functions do not vanish at that point. (C) 2010 Elsevier Inc. All rights reserved., Feb. 2011, 131, 2, 343, 362, Scientific journal
  • Not Refereed, 数理解析研究所講究録, Kyoto University, Non-vanishing of the value of L-functions attached to primitive forms at a fixed point on the critical line, Yumiko Ichihara, 2010, 1710, 29, 41
  • Refereed, LITHUANIAN MATHEMATICAL JOURNAL, SPRINGER, Estimates of a certain sum involving coefficients of cusp forms in weight and level aspects, Y. Ichihara, We consider the sum of coefficients which are in the Dirichlet series expansion of symmetric square L-functions. In this paper, we obtain two estimates of this sum in weight and level aspects. These imply two estimates of the sum of the n(2)th Fourier coefficients of cusp forms., Jun. 2008, 48, 2, 188, 202, Scientific journal
  • Refereed, KYUSHU JOURNAL OF MATHEMATICS, KYUSHU UNIV, FAC MATHEMATICS, On the Siegel-Tatuzawa theorem for a class of L-functions, Yumiko Ichihara; Kohji Matsumoto, We consider an effective lower bound of the Siegel-Tatuzawa type for general L-functions with three standard assumptions. We further assume three hypotheses in this paper that are essential in developing our argument. Under these assumptions and hypotheses, we prove a theorem of Siegel-Tatuzawa type for general L-functions. In particular, we prove such a theorem for symmetric power L-functions under certain assumptions., Mar. 2008, 62, 1, 201, 215, Scientific journal
  • Not Refereed, 数理解析研究所講究録, 京都大学, Euler 積で定義される L 関数の Siegel-Tatuzawa の定理について, 市原 由美子, 2006, 1511, 74, 81
  • Not Refereed, 数理解析研究所講究録, 京都大学, Hilbert cusp form に付随する L 関数の収束性, 市原 由美子, 2004, 1384, 37, 41
  • Refereed, JOURNAL OF THE MATHEMATICAL SOCIETY OF JAPAN, MATH SOC JAPAN, On Riesz mean for the coefficients of twisted Rankin-Selberg L-functions, Y Ichihara, Rankin obtained the asymptotic formula for the sum of coefficients of Rankin-Selberg L-series associated with a cusp form and a trivial character. Ivic-Matsumoto-Tanigawa studied the error term in it by using a mean value formula which is yielded from the Voronoi formula of the Riesz mean. In this paper, we consider more general Rankin-Selberg L-series, It is associated with two cusp forms and a non-trivial character mod d. Ivic-Matsumoto-Tanigawa's method cannot be applied directly to our case. We consider the sum of coefficients of twisted Rankin-Selberg L-series by a modification of their method., Jan. 2003, 55, 1, 81, 100, Scientific journal
  • Refereed, Japanese Journal of Mathematics, The evaluation of the sum over arithmetic progressions for the coefficients of the Rankin-Selberg series, Yumiko Ichihara, 2003, 29, 2, 297, 314, Scientific journal
  • Not Refereed, 数理解析研究所講究録, 京都大学, Rankin-Selberg L 関数の zero-free region --- Siegel-Tatuzawa 型の定理について ---, 市原 由美子, 2002, 1274, 53, 61
  • Refereed, ANALYTIC NUMBER THEORY, SPRINGER, The evaluation of the sum over arithmetic progressions for the coefficients of the Rankin-Selberg series II, Y Ichihara, 2002, 6, 173, 182, International conference proceedings
  • Not Refereed, 数理解析研究所講究録, Kyoto University, On Riesz mean for the coefficients of the twisted Rankin-Selberg L-function, Yumiko Ichihara, 2001, 1219, 235, 244
  • Not Refereed, RIMS Kokyuroku, Kyoto University, The evaluation of the sum over arithmetic progressions for the coefficients of the Rankin-Selberg series (Analytic Number Theory and Related Topics), Ichihara Yumiko, 2000, 1160, 110, 118
  • Refereed, ACTA ARITHMETICA, POLISH ACAD SCIENCES INST MATHEMATICS, The Siegel-Walfisz theorem for Rankin-Selberg L-functions associated with two cusp forms, Y Ichihara, 2000, 92, 3, 215, 227, Scientific journal
  • Not Refereed, 数理解析研究所講究録, 京都大学, 2 つの cusp form の Fourier 係数の積に対する算術級数の素数定理と Rankin-Selberg L 関数の zero-free region, 市原 由美子, 1999, 1091, 27, 35
  • Not Refereed, 中部数理フォーラム, 2つの cusp form の Fourier 係数の積に対する算術級数の素数定理と Rankin-Selberg L 関数の zero-free region, 市原 由美子, 1998, 4, 39, 50
  • Refereed, “Topics in Number Theory”, Proceedings of a Conference organized by the Institute of Mathematical Sciences, Chennai and IIT Ropar during 22–25th December, 2017, On the Occasion of the 130th Birth Anniversary of Srinivasa Ramanujan, edited by Tapas Chatterjee and Sanoli Gun, Lecture Notes Series Number 26, On the value-distribution of symmetric power L-functions, Kohji Matsumoto; Yumiko Umegaki, 2020, 147, 167, International conference proceedings

MISC

  • 2020, 44, 69, 97

Presentations

  • Oral presentation
  • Oral presentation
  • Oral presentation
  • 梅垣 敦紀; 梅垣 由美子, 愛知数論セミナー, 類数の大きな 4 次拡大体について, Oral presentation, 13 Jul. 2019
  • Yumiko Umegaki, Various Aspects of Multiple Zeta Function, On the value-distribution of the difference between logarithms of two symmetric power L-functions., Oral presentation, 25 Aug. 2017
  • 愛知数論セミナー, 保型 L 関数の対数値の平均と密度関数に関する考察, 22 Apr. 2017
  • RIMS Workshop 2016 Problems and prospects in Analytic Number Theory, On the value-distribution of the difference between logarithms of two symmetric power L-functions, Oral presentation, 02 Nov. 2016
  • 早稲田整数論セミナー, 保型 L 関数の対数値の平均と密度関数, Oral presentation, 31 Jul. 2015
  • The 15th. Joint Workshop on Number Theory between Japan and Taiwan, Non-vanishing of the automorphic L-functions at the point on the critical line., Oral presentation, 19 Mar. 2010
  • 第 2 回ゼータ若手研究集会, primitive form に対する保型 L 関数の critical line 上の点における first moment, 21 Feb. 2009
  • 第二回数論女性の集まり, 保型 L 関数の non-vanishing theorem, Oral presentation, 09 May 2009
  • CONFERENCE IN NUMBER THEORY, The first moment of the value of automorphic L-functions over primitive forms on the critical line., Oral presentation, 27 Jun. 2009
  • 日本数学会・代数学分科会, Cusp form に付随する L 関数の 1/2+it における first moment, 24 Sep. 2009
  • RIMS Workshop 2009 Analytic Number Theory and Related Topics, Non-vanishing of the value of the L-functions attached to primitive forms on the critical line., Oral presentation, 14 Oct. 2009
  • French-Japanese Winter School on Zeta and L-functions, Estimates of a certain sum involving coefficients of cusp forms in weight and level aspects., Oral presentation, 08 Jan. 2008
  • 第一回数論女性の集まり, Siegel-Tatuzawa の定理について, 17 May 2008
  • 日本数学会・代数学分科会, Siegel-Tatuzawa 型の定理について, Oral presentation, 28 Mar. 2004
  • RIMS Workshop 2004 Analytic Number Theory and Surrounding Areas, On the Siegel-Tatuzawa theorem for a class of L-functions, 19 Oct. 2004
  • 整数論シンポジウム, いくつかの L 関数の係数和の評価について, Mar. 2003
  • RIMS Workshop 2003 Analytic Number Theory and Surrounding Areas, The convergence of L-functions associated with Hilbert cusp form, 29 Sep. 2003
  • 下関数論小研究集会, Rankin-Selberg L 関数の Siegel zero について, Jan. 2002
  • Nishi Waseda Seminar on Number Theory, The evaluation of the sum over arithmetic progressions for the coefficients of the Rankin-Selberg series., Sep. 2001
  • 日本数学会・代数学分科会, Rankin-Selberg L 関数における Siegel-Tatuzawa の定理について, Oral presentation, 03 Oct. 2001
  • RIMS Workshop 2001 New Aspects of Analytic Number Theory, An analogue of the Siegel-Tatuzawa theorem for Rankin-Selberg L-functions, Oral presentation, 26 Nov. 2001
  • RIMS Workshop 2000 Analytic Number Theory --- Expectations for the 21st Century, On Riesz mean for the coefficients of the twisted Rankin-Selberg L-functions, Oral presentation, 27 Oct. 2000
  • 日本数学会・代数学分科会, Rankin-Selberg L 関数の係数の和に関する評価について, Oral presentation, 25 Mar. 1999
  • 日本数学会・代数学分科会, Rankin-Selberg series の係数 c_n に関する \sum_{n \leq x, n\eqiv a (p)} c_n の評価, Oral presentation, 28 Sep. 1999
  • RIMS Workshop 1999 Analytic Number Theory and Related Areas, The evaluation of the sum over arithmetic progressions for the coefficients of the Rankin-Selberg series., Oral presentation, Nov. 1999
  • 日本数学会・代数学分科会, The Siegel-Walfisz theorem for Rankin-Selberg L-functions associated with two cusp forms, Oral presentation, 02 Oct. 1998
  • RIMS Workshop 1998 Number Theory from the Stand Point of Analytic Number Theory, The Siegel-Walfisz Theorem for Rankin-Selberg L-functions associated with two cusp forms., Oral presentation, 19 Oct. 1998
  • 大阪大学整数論・保型形式セミナー, old form の空間の基底と保型 L 関数の central point における零の位数について, Oral presentation, 15 Oct. 2010
  • 整数論シンポジウム(早稲田大学), 保型 L 関数の critical line 上の点における non-vanishing について, Oral presentation, 19 Mar. 2010
  • 数論研究会(奈良女子大学), Primitive form に付随する L 関数の non-vanishing について, Oral presentation, 12 Jan. 2010
  • 早稲田大学整数論セミナー, Primitive form に付随する L 関数の critical line 上の点での non-vanishing について, Oral presentation, 20 Nov. 2009
  • Summer Number Theory Seminar (Queen's Univ. CANADA), On the non-vanishing and order of the zero at 1/2 for L-functions attached to cusp forms, Oral presentation, 26 Aug. 2009
  • 西早稲田数論セミナー, The first moment of the automorphic L-functions over primitive forms, Oral presentation, 02 Feb. 2009
  • 数論セミナー(明治学院大学), primitive form に対する保型 L 関数の central line 上の点における first moment, Oral presentation, 31 Jan. 2009
  • 高知大学数論セミナー, primitive form に付随する L 関数の non-vanishing theorem について, Oral presentation, 06 Dec. 2008
  • 解析数論セミナー(名古屋大学), 保型 L 関数の係数評価 (weight aspect) に関しての Voronoi formula と reflection principle, Oral presentation, 11 Jul. 2007
  • 代数学セミナー(九州大学), Euler 積で定義される L 関数の Siegel の零点について, Oral presentation, 19 Nov. 2004
  • 早稲田大学整数論セミナー, Siegel-Tatuzawa の定理について, Oral presentation, 04 Jun. 2004
  • 代数学セミナー(広島大学), Siegel-Tatuzawa の定理について, Oral presentation, 12 Dec. 2003
  • 整数論セミナー(東京都立大学), The convergence of L-functions associated with Hilbert cusp forms, Oral presentation, 23 Jun. 2003
  • 早稲田大学整数論セミナー, Rankin-Selberg L 関数の zero について, Oral presentation, 24 May 2002
  • 整数論・保型形式セミナー(大阪大学), Rankin-Selberg L 関数に対する Siegel-Tatuzawa の定理について, Oral presentation, 18 May 2001
  • 数論セミナー(明治学院大学), Rankin-Selberg L 関数における Siegel-Tatuzawa の定理の証明について, Oral presentation, 12 May 2001
  • 早稲田大学整数論セミナー, On Riesz mean for the coefficients of the twisted Rankin-Selberg series, Oral presentation, 19 Nov. 1999
  • 数論セミナー(明治学院大学), Rankin-Selberg series の係数の合同条件付き部分和の評価について, 24 Apr. 1999
  • 保型形式月例セミナー(東京大学), The Siegel-Walfisz Theorem for Rankin-Selberg L-functions associated with two cusp forms, 17 Oct. 1998
  • 早稲田大学整数論セミナー, The Siegel-Walfisz Theorem for Rankin-Selberg L-functions associated with two cusp forms, 18 Sep. 1998
  • 数論セミナー(明治学院大学), The Siegel-Walfisz Theorem for Rankin-Selberg L-functions associated with two cusp forms, 20 Jun. 1998
  • 梅垣由美子, 解析数論セミナー, primitive form に付随する Symmetric square L 関数の対数値に関する M 関数, 29 Jun. 2022

Research Projects

  • 整数論, 0, 0, 0, Competitive research funding
  • Number Theory, 0, 0, 0, Competitive research funding


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