| Project/Area Number |
16K05089
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Algebra
|
|---|
| Research Institution | The University of Tokyo (2018)
Tokyo Woman's Christian University (2016-2017) |
|---|
Principal Investigator |
Ishii Shihoko 東京大学, 大学院数理科学研究科, 名誉教授 (60202933)
|
|---|
| Research Collaborator |
Watanabe Kei-ichi
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
|
|---|
| Keywords | singularities / arc space / minimal log discrepancy / discrepancies / jet schemes / Biratinational geometry / Singularities / Jet schemes / Discrepancies / Biratinational geometry / １． Singularities / ２． Jet schemes / ３． Discrepancies / ４． Birational geometry / 特異点 / ジェットスキーム / 弧空間 |
|---|
| Outline of Final Research Achievements |
A non-smooth point on a variety is called a singularity. In order to study those singularities, we need good invariants. In this research, we introduce an invariant; Mather-Jacobian log discrepancy and study the properties of this invariant.
This invariant is interpreted in terms of the arc space on singularities of a variety. Therefore, making use of it, we obtain Inversion of Adjunction for the base field of positive characteristic and finite determinacy for
the M-J log discrepancy for surfaces of characteristic 0.
|
| Academic Significance and Societal Importance of the Research Achievements |
多様体が滑らかであれば，コホモロジーの消滅定理をはじめとして，色々な良い性質が成立し，多様体全体の様相がわかりやすいのであるが，特異点があるとそれがわかりにくくなる．特異点をよく知ることで，多様体の理解を深めようというのが本研究の意義である．この研究は数学的に意義があることはもちろん，特異点の不変数の一つである log canonical threshold が学習理論において，重要な役割を果たすことが知られていることからもわかるように，社会にとっても意義のあることである．
|
