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

Deepening singularity theory and low dimensional geometry

Research Project

Project/Area Number 26400087
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Geometry
Research InstitutionKobe University

Principal Investigator

Saji Kentaro  神戸大学, 理学研究科, 准教授 (70451432)

Project Period (FY) 2014-04-01 – 2018-03-31
Project Status Completed (Fiscal Year 2017)
Budget Amount *help
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywords特異点 / カスプ辺 / 接触構造 / 曲率 / 曲面論 / 表現公式 / カスプ的交差帽子 / モラン特異点 / スワローテイル / 波面 / 特異点の認識問題 / 線織面
Outline of Final Research Achievements

For deepening singularity theory, I obtained criteria for Morin singularities for the case of the dimension of the source space and the target space is not the same. By using criteria for Morin singularities, I gave the number of right-left isotopy classes.
For low dimensional geometry, I generalized a formula for the number of singular points and the Euler characteristic to singularities of bundle homomorphisms. I also gave a normal form by only using isometric coordinate transformation of the target space for cuspidal edges and swallowtails. Moreover, I clarified the differential geometric meanings for modulus appeared in the lower degree terms. By using that form, I obtained generic configurations of asymptotic lines and characteristic lines of that singularities. I also studied singularities of solution surfaces of certain differential equation and that of surfaces which approximate the cuspidal edge.

Report

(5 results)
  • 2017 Annual Research Report   Final Research Report ( PDF )
  • 2016 Research-status Report
  • 2015 Research-status Report
  • 2014 Research-status Report
  • Research Products

    (47 results)

All 2019 2018 2017 2016 2015 2014 Other

All Int'l Joint Research (6 results) Journal Article (20 results) (of which Int'l Joint Research: 4 results,  Peer Reviewed: 19 results,  Open Access: 6 results,  Acknowledgement Compliant: 9 results) Presentation (19 results) (of which Int'l Joint Research: 6 results,  Invited: 5 results) Remarks (1 results) Funded Workshop (1 results)

  • [Int'l Joint Research] サンパウロ州立大学(ブラジル)

    • Related Report
      2017 Annual Research Report
  • [Int'l Joint Research] バレンシア大学(スペイン)

    • Related Report
      2017 Annual Research Report
  • [Int'l Joint Research] バレンシア大学(スペイン)

    • Related Report
      2016 Research-status Report
  • [Int'l Joint Research] サンパウロ州立大学サンジョセドヒオプレート校(ブラジル)

    • Related Report
      2016 Research-status Report
  • [Int'l Joint Research] バレンシア大学(スペイン)

    • Related Report
      2015 Research-status Report
  • [Int'l Joint Research] サンパウロ大学サンジョゼドリオプレート校(ブラジル)

    • Related Report
      2015 Research-status Report
  • [Journal Article] On pairs of geometric foliations on a cuspidal edge2019

    • Author(s)
      Kentaro Saji
    • Journal Title

      Adv. Stud. Pure Math

      Volume: 印刷中

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed
  • [Journal Article] On the geometry of folded cuspidal edges2018

    • Author(s)
      Oset Sinha Raul、Saji Kentaro
    • Journal Title

      Revista Matematica Complutense

      Volume: - Issue: 3 Pages: 627-650

    • DOI

      10.1007/s13163-018-0257-6

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Addendum: Singularities of flat fronts in hyperbolic space2018

    • Author(s)
      Kokubu Masatoshi、Rossman Wayne、Saji Kentaro、Umehara Masaaki、Yamada Kotaro
    • Journal Title

      Pacific Journal of Mathematics

      Volume: 294 Issue: 2 Pages: 505-509

    • DOI

      10.2140/pjm.2018.294.505

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Geometry of cuspidal edges with boundary2018

    • Author(s)
      Martins Luciana F.、Saji Kentaro
    • Journal Title

      Topology and its Applications

      Volume: 234 Pages: 209-219

    • DOI

      10.1016/j.topol.2017.11.024

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Normal form of the swallowtail and its applications2018

    • Author(s)
      Kentaro Saji
    • Journal Title

      International J. Math.

      Volume: 印刷中

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Flat surfaces along cuspidal edges2017

    • Author(s)
      Shyuichi Izumiya, Kentaro Saji, N. Takeuchi
    • Journal Title

      Journal of Singularities

      Volume: 16 Pages: 73-100

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] An index formula for a bundle homomorphism of the tangent bundle into a vector bundle of the same rank, and its applications2017

    • Author(s)
      Saji Kentaro、Umehara Masaaki、Yamada Kotaro
    • Journal Title

      J. Math. Soc. Japan

      Volume: 69 Pages: 417-457

    • NAID

      130005310476

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Behavior of Gaussian Curvature and Mean Curvature Near Non-degenerate Singular Points on Wave Fronts2016

    • Author(s)
      Luciana F, Martins, Kentaro Saji, Masaaki Umehara and Kotaro Yamada
    • Journal Title

      Springer Proceedings in Mathematics & Statistics

      Volume: 154 Pages: 1-39

    • DOI

      10.1007/978-4-431-56021-0_14

    • ISBN
      9784431560197, 9784431560210
    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Extensions of Koenderink's formula2016

    • Author(s)
      Fukui, Toshizumi; Hasegawa, Masaru; Saji, Kentaro
    • Journal Title

      J. Gokova Geom. Topol. GGT

      Volume: 10 Pages: 42-59

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Journal Article] Criteria for Morin singularities into higher dimensions2016

    • Author(s)
      Saji, Kentaro
    • Journal Title

      RIMS Kokyuroku Bessatsu

      Volume: 55

    • Related Report
      2015 Research-status Report
  • [Journal Article] Isotopy of Morin singularities2016

    • Author(s)
      Saji, Kentaro
    • Journal Title

      Houston J. Math.

      Volume: 未定

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] An index formula for a bundle homomorphism of the tangent bundle into a vector bundle of the same rank, and its applications2016

    • Author(s)
      Saji, Kentaro; Umehara, Masaaki; Yamada, Kotaro
    • Journal Title

      J. Math. Soc. Japan.

      Volume: 未定

    • NAID

      130005310476

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Criteria for Morin singularities for maps into lower dimensions, and applications2016

    • Author(s)
      Saji, Kentaro
    • Journal Title

      Contemporary Math.

      Volume: 未定

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Fold singularities on spacelike CMC surfaces in Lorentz-Minkowski space2016

    • Author(s)
      Honda, Atsufumi; Koiso, Miyuki; Saji, Kentaro
    • Journal Title

      Hokkaido Math. J.

      Volume: 未定

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Schwarz maps for the hypergeometric differential equation2015

    • Author(s)
      Fujimori, Shoichi; Noro, Masayuki; Saji, Kentaro; Sasaki, Takeshi; Yoshida, Masaaki.
    • Journal Title

      Internat. J. Math.

      Volume: 26 Issue: 06 Pages: 1541002-1541002

    • DOI

      10.1142/s0129167x15410025

    • Related Report
      2015 Research-status Report 2014 Research-status Report
    • Peer Reviewed
  • [Journal Article] Intrinsic properties of surfaces with singularities2015

    • Author(s)
      M. Hasegawa, A. Honda, K. Naokawa, K. Saji, M. Umehara, K. Yamada
    • Journal Title

      International Journal of Mathatematics

      Volume: 26 Issue: 04 Pages: 1-34

    • DOI

      10.1142/s0129167x1540008x

    • Related Report
      2015 Research-status Report 2014 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Journal Article] Geometric invariants of cuspidal edges2015

    • Author(s)
      Martins Luciana; Saji, Kentaro
    • Journal Title

      Canadian J. Math.

      Volume: 68 Issue: 2 Pages: 445-462

    • DOI

      10.4153/cjm-2015-011-5

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Legendrian dual surfaces in hyperbolic 3-space2015

    • Author(s)
      K. Saji and H. Yildirim
    • Journal Title

      Annales Polonici Matematici

      Volume: 未定

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Geometric invariants of cuspidal edges2015

    • Author(s)
      L. Martins and K. Saji
    • Journal Title

      Canadian Journal of Mathematics

      Volume: 未定

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Koenderink type theorems for fronts2014

    • Author(s)
      K. Saji
    • Journal Title

      Sci. China Math.

      Volume: 57 Pages: 1841-1866

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] ベクトル場と関数の接触とその応用2018

    • Author(s)
      佐治健太郎
    • Organizer
      特異点論とその応用
    • Related Report
      2017 Annual Research Report
  • [Presentation] 非有界平均曲率をもつ特異点付き回転面2018

    • Author(s)
      佐治健太郎
    • Organizer
      幾何学と特異点
    • Related Report
      2017 Annual Research Report
  • [Presentation] Singular surfaces of revolution with prescribed unbounded mean curvature2018

    • Author(s)
      Kentaro Saji
    • Organizer
      第7回神戸特異点研究会
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research
  • [Presentation] スワローテイルの SO (3)- 標準形と幾何的模様2018

    • Author(s)
      佐治健太郎
    • Organizer
      日本数学会春季年会
    • Related Report
      2017 Annual Research Report
  • [Presentation] スワローテイルのノーマルフォームとその応用2017

    • Author(s)
      佐治健太郎
    • Organizer
      微分幾何学と特異点論の応用
    • Related Report
      2017 Annual Research Report
  • [Presentation] ランフォイドカスプの不変量とその応用2017

    • Author(s)
      佐治健太郎
    • Organizer
      山口佳三先生退職記念研究集会
    • Related Report
      2017 Annual Research Report
  • [Presentation] Normal form of swallowtail and its applications2017

    • Author(s)
      Kentaro Saji
    • Organizer
      Geometric and Algebraic Singularity Theory
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Geometric foliations of fronts2017

    • Author(s)
      Kentaro Saji
    • Organizer
      The 2nd OCAMI-KOBE-WASEDA Joint International Workshop on Differential Geometry and Integrable Systems
    • Place of Presentation
      大阪市立大学
    • Related Report
      2016 Research-status Report
    • Int'l Joint Research
  • [Presentation] Geometry of singular surfaces2016

    • Author(s)
      Kentaro Saji
    • Organizer
      School on Singularity Theory
    • Place of Presentation
      Sao Paulo University, Sao Carlos, Brazil
    • Year and Date
      2016-07-19
    • Related Report
      2016 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 誰にでもできる特異点の判定法2016

    • Author(s)
      佐治健太郎
    • Organizer
      Encounter with Mathematics
    • Place of Presentation
      中央大学(東京都・文京区)
    • Year and Date
      2016-03-12
    • Related Report
      2015 Research-status Report
    • Invited
  • [Presentation] Invariants of cuspidal edges and flat surface2016

    • Author(s)
      Kentaro Saji
    • Organizer
      International Workshop on Real and Complex Singularities
    • Place of Presentation
      Sao Paulo University, Sao Carlos, Brazil
    • Related Report
      2016 Research-status Report
    • Int'l Joint Research
  • [Presentation] 4次元トポロジー2015

    • Author(s)
      佐治健太郎
    • Organizer
      ファイバー型モラン特異点の判定法とその応用
    • Place of Presentation
      大阪市立大学(大阪府・大阪市)
    • Year and Date
      2015-11-20
    • Related Report
      2015 Research-status Report
  • [Presentation] On pairs of geometric foliations on a cuspidal edge2015

    • Author(s)
      Kentaro Saji
    • Organizer
      Geometric Singularity Theory
    • Place of Presentation
      ワルシャワ(ポーランド)
    • Year and Date
      2015-09-10
    • Related Report
      2015 Research-status Report
    • Int'l Joint Research
  • [Presentation] 可微分写像の特異点の判定法とその応用2015

    • Author(s)
      佐治健太郎
    • Organizer
      トポロジーシンポジウム
    • Place of Presentation
      名古屋工業大学(愛知県・名古屋市)
    • Year and Date
      2015-08-09
    • Related Report
      2015 Research-status Report
    • Invited
  • [Presentation] カスプ辺の幾何的模様2015

    • Author(s)
      佐治健太郎
    • Organizer
      日本数学会春季年会トポロジー分科会
    • Place of Presentation
      明治大学 駿河台キャンパス リバティタワー
    • Year and Date
      2015-03-21
    • Related Report
      2014 Research-status Report
  • [Presentation] Isotopy of map-germs and Morin singularities2014

    • Author(s)
      Kentaro Saji
    • Organizer
      Transformations and singularities
    • Place of Presentation
      DA09 E10 Konferenzraum, Technische Universitat Wien
    • Year and Date
      2014-09-17
    • Related Report
      2014 Research-status Report
    • Invited
  • [Presentation] Geometry of singularities of fronts2014

    • Author(s)
      Kentaro Saji
    • Organizer
      The 2nd Franco-Japanese-Vietnamese symposium on singularities
    • Place of Presentation
      北海道大学理学部7-310
    • Year and Date
      2014-08-29
    • Related Report
      2014 Research-status Report
    • Invited
  • [Presentation] Criteria and geometries of Morin singularities2014

    • Author(s)
      Kentaro Saji
    • Organizer
      13th International Workshop on Real and Complex Singularities
    • Place of Presentation
      Instituto de Ciencias Mateaticas e de Computacao Universidade de Sao Paulo, Campus Sao Carlos
    • Year and Date
      2014-07-29
    • Related Report
      2014 Research-status Report
  • [Presentation] 異次元モラン特異点の判定法とその応用2014

    • Author(s)
      佐治健太郎
    • Organizer
      写像の特異点論及び関連する科学の諸問題
    • Place of Presentation
      都城工業高等専門学校多目的ホール
    • Year and Date
      2014-06-07
    • Related Report
      2014 Research-status Report
  • [Remarks] 研究費と得られた主な成果

    • URL

      http://www.math.kobe-u.ac.jp/HOME/saji/math/kaken.html

    • Related Report
      2017 Annual Research Report 2016 Research-status Report 2015 Research-status Report 2014 Research-status Report
  • [Funded Workshop] Singularities in Generic Geometry and applications2015

    • Place of Presentation
      神戸大学百年記念館・京都大学数理解析研究所
    • Year and Date
      2015-06-03
    • Related Report
      2015 Research-status Report

URL: 

Published: 2014-04-04   Modified: 2019-03-29  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi