4 papers
Milnor-type invariants for surface-links and cut-diagrams
Benjamin Audoux, Jean-Baptiste Meilhan, Akira Yasuhara
We generalize Milnor link invariants to surface-links in 4-space, possibly with boundary. To this end, we introduce the notion of cut-diagram, which is a 2-dimensional analogue of…
Welded graphs, Wirtinger groups and knotted punctured spheres
Benjamin Audoux, Jean-Baptiste Meilhan, Akira Yasuhara
We develop a general diagrammatic theory of welded graphs, and provide an extension of Satoh's Tube map from welded graphs to ribbon surface-links. As a topological application, we…
The classification of links up to clasp-pass moves
Jean-Baptiste Meilhan, Akira Yasuhara
We give a complete classification of links up to clasp-pass moves, which coincides with Habiro's -equivalence. We also classify links up to band-pass and band-# moves, which a…
Milnor Invariants --From classical links to surface-links, and beyond--
Akira Yasuhara
This is an English translation of the expository article written by the author in Japanese for publication in {\em Sugaku}. The author will explain Milnor invariants from the viewp…