TY - JOUR T1 - $H(2)$-Unknotting Number of a Knot AU - Kanenobu , Taizo AU - Miyazawa , Yasuyuki JO - Communications in Mathematical Research VL - 5 SP - 433 EP - 460 PY - 2021 DA - 2021/07 SN - 25 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/cmr/19362.html KW - knot, $H(2)$-move, $H(2)$-unknotting number, signature, Arf invariant, Jones polynomial, $Q$ polynomial. AB -

An $H(2)$-move is a local move of a knot which is performed by adding a half-twisted band. It is known an $H(2)$-move is an unknotting operation. We define the $H(2)$-unknotting number of a knot $K$ to be the minimum number of $H(2)$-moves needed to transform K into a trivial knot. We give several methods to estimate the $H(2)$-unknotting number of a knot. Then we give tables of $H(2)$-unknotting numbers of knots with up to 9 crossings.