Arf invariants of strongly invertible knots obtained from unknotting number one knots (Q1804714)

From MaRDI portal





scientific article; zbMATH DE number 755446
Language Label Description Also known as
English
Arf invariants of strongly invertible knots obtained from unknotting number one knots
scientific article; zbMATH DE number 755446

    Statements

    Arf invariants of strongly invertible knots obtained from unknotting number one knots (English)
    0 references
    0 references
    15 May 1995
    0 references
    It is well-known, that if \(k\) is a knot of unknotting number one, the double cover of \(S^3\) branched over \(k\) is a 3-manifold \(\Sigma_2(k)\); we can obtain \(\Sigma_2(k)\) by Dehn surgery on some knot \(C\) in \(S^3\). This paper produces an effective method to determine the Arf invariant \(\text{Arf}(C)\) by using the Conway polynomial \(\nabla_L(z)=\sum^\infty_{n=0} a_{2n}(k)z^{2n}\), where \(a_{2n}(k)=0\) except a finite number of \(n:\text{Arf}(C)=a_4(k)\pmod2\).
    0 references
    branched covering
    0 references
    knot
    0 references
    unknotting number
    0 references
    Dehn surgery
    0 references
    Arf invariant
    0 references
    Conway polynomial
    0 references

    Identifiers