EQUIVALENCE OF SYMMETRIC UNION DIAGRAMS
EQUIVALENCE OF SYMMETRIC UNION DIAGRAMS
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对称联合图的等价
DOI:
10.1142/s0218216507005555
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发表时间:
2007
影响因子:
0.5
通讯作者:
C. Lamm
中科院分区:
文献类型:
--
作者:
Michael Eisermann;C. Lamm
Motivated by the study of ribbon knots we explore symmetric unions, a beautiful construction introduced by Kinoshita and Terasaka 50 years ago. It is easy to see that every symmetric union represents a ribbon knot, but the converse is still an open problem. Besides existence it is natural to consider the question of uniqueness. In order to attack this question we extend the usual Reidemeister moves to a family of moves respecting the symmetry, and consider the symmetric equivalence thus generated. This notion being in place, we discuss several situations in which a knot can have essentially distinct symmetric union representations. We exhibit an infinite family of ribbon two-bridge knots each of which allows two different symmetric union representations.