Torisu's unknotting-number-one conjecture for Montesinos knots

Let KK be a Montesinos knot of length three. Write M(0;(p,r),(q,s),(2mn±1,2n2))\mathcal{M}(0;(p,r),(q,s),(2mn\pm1,2n^2)) for the Montesinos-knot notation used in the source, where pp, qq, rr, ss, mm, and nn are non-zero integers, mm and nn are coprime, and ps+rq=1ps+rq=1.

Torisu's conjecture. The knot satisfies u(K)=1u(K)=1 if and only if

K=M(0;(p,r),(q,s),(2mn±1,2n2)).K=\mathcal{M}(0;(p,r),(q,s),(2mn\pm1,2n^2)).

Torisu proved this equivalence when the unknotting operation is realised in a standard diagram, but the unrestricted statement is presented as a conjecture; it would follow from the Seifert fibering conjecture described below.

Sources & referencesView supporting material

Primary source

Dorothy Buck, Julian Gibbons and Eric Staron, “Pretzel Knots with Unknotting Number One”, arXiv:1109.4560 (2012).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.