Invariants of theta-curves and other graphs in 3-space
The authors define and demonstrate the utility of an invariant of embedding type of graphs in \(E^ 3\) isomorphic to either the lower case greek letter \(\theta\), or the complete graph on four vertices. The invariant is the link type of the boundary of a surface in \(E^ 3\) with spine the graph and Seifert linking form 0.
scientific article; zbMATH DE number 221863
scientific article