Decision of triviality of knots and search for unknotting moves using quandles
Project/Area Number |
16K05157
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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 |
Geometry
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Research Institution | Japan Women's University |
Principal Investigator |
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Project Period (FY) |
2016-04-01 – 2019-03-31
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Project Status |
Completed (Fiscal Year 2018)
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Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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Keywords | 自明結び目 / カンドル / カンドル彩色 / 幾何学 / 位相幾何学 / 結び目理論 |
Outline of Final Research Achievements |
A knot is a circle in the 3-dimensional space R3. Two knots are regarded as the same if one is deformed into the other by a continuous deformation of R3 keeping its whole shape. A knot is called trivial if it can be deformed so that it lies in a plane. A trivial knot is a knot which can be untangled. There is an algebra called quandle which has axioms closely related to the elementary moves on knot diagrams. There are many studies on quandle colorings. A quandle coloring assigns elements of a quandle to arcs of a knot diagram so that the crossing condition is satisfied at each crossing. If a knot diagram has only trivial quandle coloring for any quandle, then it represents the trivial knot. Using this fact, we find a finite algorithm to decide a given knot diagram represents the trivial knot. We showed that this algorithm works for all the diagram of the trivial knot with 11 or less number of crossings.
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Academic Significance and Societal Importance of the Research Achievements |
与えられた結び目が自明であるか否か判定する有限アルゴリズムは、Hakenや、HassとLagariasや、Dynnikovによる研究などがある。また、カンドルを用いて与えられた結び目がほどけないことを示すことは多くの研究がある。ここでは、カンドルを用いて与えられた結び目が自明結び目であることを判定する方法を考えた。カンドルを用いることで、自明結び目をほどくための紐の動かし方の手掛かりが得られると期待している。自然界のDNAの1パーセントは結び目になっているという研究や、DNAを輪の形にしてから酵素を作用させると、酵素の働き方がよく理解できるという研究もあり、その方面への応用があると期待する。
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Report
(4 results)
Research Products
(5 results)