Understanding exotic spheres from the viewpoint of global singularity theory of smooth maps
| Project/Area Number |
18F18752
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 外国 |
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| Research Field |
Geometry
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| Research Institution | Kyushu University |
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Principal Investigator |
佐伯 修 (2018-2019) 九州大学, マス・フォア・インダストリ研究所, 教授 (30201510)
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| Co-Investigator(Kenkyū-buntansha) |
Wrazidlo Dominik 九州大学, マス・フォア・インダストリ研究所, 学術研究員 (40901054)
WRAZIDLO DOMINIK 九州大学, マス・フォア・インダストリ研究所, 外国人特別研究員
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| Project Period (FY) |
2018-11-09 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2020: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2019: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2018: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | fold singularities / rational homologyspheres / linking form / intersection spaces / toric varieties / bordism of smooth maps / B_2 singularity / fold singularity / smooth map germ / homotopy sphere / SKK-group / signature / intersection space / cobordism of smooth maps / Morse theory / surgery theory / fold map / elimination of cusps |
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| Outline of Annual Research Achievements |
In a recent preprint (arXiv: http://arxiv.org/abs/2009.05928), we studied the existence and construction problems for special generic maps of rational homology spheres. The novelty of our approach is to consider the torsion subgroup of the integral homology of such manifolds. We showed that if a rational homology sphere of odd dimension n = 2k + 1 > 4 admits a special generic map into a Euclidean space of dimension < n, then the cardinality of its integral homology group of degree k is a square. On the one hand, we showed that any square can can be realized in our homological condition. On the other hand, there are examples of rational homology spheres that do not satisfy our homological condition. Our results paved the way to a subsequent project, in which we study special generic maps of highly connected manifolds in terms of the linking form, which is a torsion analog of the intersection form. In another project, we developed a new approach to intersection spaces that is based on Sullivan's PL polynomial differential forms. Our result implies uniqueness of the rational cohomology ring of intersection spaces. This result is a new discovery in the research field, and we published the case of isolated singularities. In ongoing work, we generalize our approach along the construction of Agustin and Fernandez de Bobadilla to a class of singular spaces of arbitrary stratification depth including toric varieties. Moreover, in joint work with T. Essig, we are finalizing a preprint about the construction of a fundamental class for intersection spaces in stratification depth two.
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| Research Progress Status |
令和2年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和2年度が最終年度であるため、記入しない。
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Report
(3 results)
Research Products
(27 results)
