Cutting arcs for torus links and trees

Abstract

Among all torus links, we characterise those arising as links of simple plane curve singularities by the property that their fibre surfaces admit only a finite number of cutting arcs that preserve fibredness. The same property allows a characterisation of Coxeter-Dynkin trees (i.e., $A_n$, $D_n$, $E_6$, $E_7$ and $E_8$) among all positive tree-like Hopf plumbings.Comment: 27 pages, 18 figures. Results have been extended to cover all Coxeter-Dynkin trees in the new versio