2019 Fiscal Year Final Research Report
A study on generic construction
Project/Area Number |
17K05350
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Foundations of mathematics/Applied mathematics
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Research Institution | Hosei University |
Principal Investigator |
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Project Period (FY) |
2017-04-01 – 2020-03-31
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Keywords | モデル理論 / ジェネリック構造 |
Outline of Final Research Achievements |
There exists some famous conjecture which says that if the number of countable models of a theory is finite and not one then the theory is unstable. If there exists a counter-example of the conjecture,it must have a special type. We construct a non omega-categorical theory with a special type, modifying some known example. Holographic structures are similar to omega-categorical structures. There exists a holographic structure that is not omega-categorical. This example is constructed from a field structure. So the following problem naturally arises: Is there a non omega-categorical holographic structure in which no field is definable? We give a positive answer to the problem using generic construction.
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Free Research Field |
数理論理学
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Academic Significance and Societal Importance of the Research Achievements |
Lachlan予想はモデル理論においてよく知られた予想であるが,約50年前のものであり,現在はこの予想を研究対象にしている研究者は少ない.しかし,モデル理論の発展とともに新たな道具が開発されており,この古い予想にうまく適用できるのではないかと考えた.まだ研究は半ばであるが,少しずつ解決に近づいていると考える.
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