An Index-Type Invariant of Knot Diagrams Giving Bounds for Unknotting Framed Unknots

Piotr Suwara; Albert Yue

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arXiv · 1707.02369

An Index-Type Invariant of Knot Diagrams Giving Bounds for Unknotting Framed Unknots

Piotr Suwara·Albert Yue

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Abstract

We introduce a new knot diagram invariant called the Self-Crossing Index (SCI). Using SCI, we provide bounds for unknotting two families of framed unknots. For one of these families, unknotting using framed Reidemeister moves is significantly harder than unknotting using regular Reidemeister moves. We also investigate the relation between SCI and Arnold's curve invariant St, as well as the relation with Hass and Nowik's invariant, which generalizes cowrithe. In particular, the change of SCI under {\Omega}3 moves depends only on the forward/backward character of the move, similar to how the change of St or cowrithe depends only on the positive/negative quality of the move.

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BibTeX RIS

Piotr Suwara, Albert Yue. 2017-07-07. An Index-Type Invariant of Knot Diagrams Giving Bounds for Unknotting Framed Unknots. https://arxiv.org/abs/1707.02369

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