Arrow calculus for welded and classical links

We develop a calculus for diagrams of knotted objects. We define arrow presentations, which encode the crossing information of a diagram into arrows in a way somewhat similar to Gauss diagrams, and more generally $w$ –tree presentations, which can be seen as “higher-order Gauss diagrams”. This arrow calculus is used to develop an analogue of Habiro’s clasper theory for welded knotted objects, which contain classical link diagrams as a subset. This provides a “realization” of Polyak’s algebra of arrow diagrams at the welded level, and leads to a characterization of finite-type invariants of welded knots and long knots. As a corollary, we recover several topological results due to Habiro and Shima and to Watanabe on knotted surfaces in $4$ –space. We also classify welded string links up to homotopy, thus recovering a result of the first author with Audoux, Bellingeri and Wagner.

Dedicated to Professor Shin'ichi Suzuki on his 77th birthday

Keywords

knot diagrams, finite-type invariants, Gauss diagrams, claspers

Mathematical Subject Classification 2010

Primary: 57M25, 57M27

References

Publication

Received: 1 March 2018

Revised: 13 July 2018

Accepted: 10 August 2018

Published: 6 February 2019

Authors

Jean-Baptiste Meilhan
CNRS Institut Fourier Université Grenoble Alpes Grenoble France
http://www-fourier.ujf-grenoble.fr/~meilhan/
Akira Yasuhara
Faculty of Commerce Waseda University Shinjuku-ku Tokyo Japan

Volume 19, issue 1 (2019)

Jean-Baptiste Meilhan and Akira Yasuhara

Abstract

Keywords

Mathematical Subject Classification 2010

References

Publication

Authors