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Geometry of curves and surfaces with singularities

Research Project

Project/Area Number 19204005
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field Geometry
Research InstitutionOsaka University

Principal Investigator

UMEHARA Masaaki  Osaka University, 大学院・理学研究科, 教授 (90193945)

Co-Investigator(Kenkyū-buntansha) YAMADA Kotaro  東京工業大学, 大学院・理工学研究科, 教授 (10221657)
HASHIMOTO Hideya  名城大学, 理工学部, 教授 (60218419)
MASHIMO Katsuya  法政大学, 理工学部, 教授 (50157187)
MABUCHI Toshiki  大阪大学, 大学院・理学研究科, 教授 (80116102)
KOISO Norihito  大阪大学, 大学院・理学研究科, 教授 (70116028)
GOTO Ryushi  大阪大学, 大学院・理学研究科, 准教授 (30252571)
ENOKI Ichiro  大阪大学, 大学院・理学研究科, 准教授 (20146806)
W.F. Rossman  神戸大学, 理学部, 教授 (50284485)
MIYAOKA Reiko  東北大学, 大学院・理学研究科, 教授 (70108182)
KOKUBU Masatoshi  東京電機大学, 工学部, 教授 (50287439)
FUJIMORI Shoichi  福岡教育大学, 教育学部, 准教授 (00452706)
AGAOKA Yoshio  広島大学, 大学院・理学研究科, 教授 (50192894)
Project Period (FY) 2007 – 2010
Project Status Completed (Fiscal Year 2010)
Budget Amount *help
¥23,270,000 (Direct Cost: ¥17,900,000、Indirect Cost: ¥5,370,000)
Fiscal Year 2009: ¥7,540,000 (Direct Cost: ¥5,800,000、Indirect Cost: ¥1,740,000)
Fiscal Year 2008: ¥7,540,000 (Direct Cost: ¥5,800,000、Indirect Cost: ¥1,740,000)
Fiscal Year 2007: ¥8,190,000 (Direct Cost: ¥6,300,000、Indirect Cost: ¥1,890,000)
Keywords微分幾何 / ガウス曲率 / 平均曲率 / 波面 / 特異点 / 双対性 / 極大曲面 / 変曲点 / 極小曲面
Research Abstract

This research was focused on the geometry of curves and surfaces with singularities. We gave a useful criterion for A_k singular points on hypersurfaces, and applied it to the study of inflection points on hypersurfaces. This riterion enabled us to define A_k singularities of wave front without assuming the existence of an ambient space. In fact, we defined the notion "coherent tangent bundle", giving an intrinsic formulation for wave fronts and several other applications. Moreover, we investigated maximal surfaces in Lorentz-Minkowski space and constant mean curvature surfaces in de Sitter space, and constructed several interesting new examples with singularities but still having certain kind of completeness.
Additionally, the head investigator and coinvestigators held several workshops (both domestic and international), which related in many fruitful discussions with geometers studying relating fields.

Report

(5 results)
  • 2010 Final Research Report ( PDF )
  • 2009 Annual Research Report   Self-evaluation Report ( PDF )
  • 2008 Annual Research Report
  • 2007 Annual Research Report
  • Research Products

    (19 results)

All 2010 2009 2008 2007

All Journal Article (17 results) (of which Peer Reviewed: 16 results) Presentation (2 results)

  • [Journal Article] Flat surfaces with singularities in Euclidean 3-space2009

    • Author(s)
      S.Murata, M.Umehara
    • Journal Title

      Journal of Differential Geometry 82

      Pages: 279-316

    • Related Report
      2010 Final Research Report 2009 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Complete bounded null curves immersed in C3 and PSL(2, C)2009

    • Author(s)
      F.Martin, M.Umehara, K.Yamada
    • Journal Title

      Calculus of Variations and Partial Differential Equations 36

      Pages: 119-139

    • Related Report
      2010 Final Research Report
    • Peer Reviewed
  • [Journal Article] Ak singularities of wave fronts2009

    • Author(s)
      K.Saji, M.Umehara, K.Yamada
    • Journal Title

      Mathematical Proceedings of the Cambridge Philosophical Society 146

      Pages: 731-746

    • Related Report
      2010 Final Research Report
    • Peer Reviewed
  • [Journal Article] The geometry of fronts2009

    • Author(s)
      K.Saji, M.Umehara, K.Yamada
    • Journal Title

      Ann.of Math. 169

      Pages: 491-529

    • Related Report
      2010 Final Research Report
    • Peer Reviewed
  • [Journal Article] Flat surfaces with singularities in Euclidean 3-space2009

    • Author(s)
      S. Murata, M. Umehara
    • Journal Title

      journal of Differential Geometry 82

      Pages: 279-316

    • Related Report
      2009 Self-evaluation Report
    • Peer Reviewed
  • [Journal Article] Complete bounded null curves immersed in C3 and PSL (2, C)2009

    • Author(s)
      F. Martin, M. Umehara, K. Yamada
    • Journal Title

      Calculus of Variations and Partial Differential Equations 36

      Pages: 119-139

    • Related Report
      2009 Self-evaluation Report
    • Peer Reviewed
  • [Journal Article] Mathematical Proceedings of the Cambridge Philosophical Society2009

    • Author(s)
      K. Saji, M. Umehara, K. Yamada, Ak singularities of wave fronts
    • Journal Title

      Volume 146

      Pages: 731-746

    • Related Report
      2009 Self-evaluation Report
    • Peer Reviewed
  • [Journal Article] The geometry of fronts2009

    • Author(s)
      K. Saji, M. Umehara, K. Yamada
    • Journal Title

      Ann. of Math 169

      Pages: 491-529

    • Related Report
      2009 Self-evaluation Report
    • Peer Reviewed
  • [Journal Article] New maximal surfaces in Minkowski 3-space with arbitrary genus and their cousins in de Sitter 3-space2009

    • Author(s)
      S.Fujimori, W.Rossman, M.Umehara, K.Yamada, S.D.Yang
    • Journal Title

      Results in Math. 56

      Pages: 41-82

    • Related Report
      2009 Annual Research Report
    • Peer Reviewed
  • [Journal Article] The geometry of fronts2009

    • Author(s)
      K.Saji, M.Umehara, K.Yamada
    • Journal Title

      Ann. of Math. 169

      Pages: 491-529

    • Related Report
      2009 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Singularities of maximal surfaces2008

    • Author(s)
      S.Fujimori, K.Saji, M.Umehara, K.Yamada
    • Journal Title

      Math.Z. 259

      Pages: 827-848

    • Related Report
      2010 Final Research Report
    • Peer Reviewed
  • [Journal Article] Inflection points and double tangents on anti-convex curves in the real projective plane2008

    • Author(s)
      G.Thorbergsson, M.Umehara
    • Journal Title

      Tohoku Mathematical Journal 60

      Pages: 149-181

    • NAID

      110006691406

    • Related Report
      2010 Final Research Report
    • Peer Reviewed
  • [Journal Article] Singularities of maximal surfaces2008

    • Author(s)
      S. Fujimori, K. Saji, M. Umehara, K. Yamada
    • Journal Title

      Math. Z 259

      Pages: 827-848

    • Related Report
      2009 Self-evaluation Report
  • [Journal Article] Inflection points and double tangents on anti-convex curves in the real projective plane2008

    • Author(s)
      G. Thorbergsson, M. Umehara
    • Journal Title

      Tohoku Mathematical Journal 60

      Pages: 149-181

    • NAID

      110006691406

    • Related Report
      2009 Self-evaluation Report 2008 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Cuspidal cross caps and singularities of maximal surfaces2008

    • Author(s)
      S. Fujimori, K. Saji, M. Umehara, K. Yamada
    • Journal Title

      Mathematische Zeitschrift 259

      Pages: 827-848

    • Related Report
      2008 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Flat Moebius strips of given isotopy type in R^3 whose centerlines are geodesic or lines of curvature2008

    • Author(s)
      Y. Kurono, M. Umehara
    • Journal Title

      Geometriae Dedicata 134

    • Related Report
      2008 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Flat fronts in hyperbolic 3-space and their caustics2007

    • Author(s)
      M. Kokubu, W. Rossman, M. Umehara and K. Yamada
    • Journal Title

      Journal of the Mathematical Society of Japan 265--299

      Pages: 59-59

    • NAID

      10019540696

    • Related Report
      2007 Annual Research Report
    • Peer Reviewed
  • [Presentation] 波面の幾何学-その内的双対性とGauss-Bonnetの定理への応用-2010

    • Author(s)
      梅原雅顕
    • Organizer
      日本数学会2010年度年会・企画特別講演
    • Place of Presentation
      慶應義塾大学・理工学部
    • Year and Date
      2010-03-26
    • Related Report
      2010 Final Research Report
  • [Presentation] 波面の幾何学-その内的双対性と Gauss-Bonnet の定理への応用-2010

    • Author(s)
      梅原雅顕
    • Organizer
      日本数学会2010年度年会・企画特別講演
    • Place of Presentation
      慶應義塾大学・理工学部 (神奈川県)
    • Year and Date
      2010-03-26
    • Related Report
      2009 Self-evaluation Report

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Published: 2007-04-01   Modified: 2016-04-21  

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