Computing ribbon obstructions for colored knots

Patricia Cahn, Alexandra Kjuchukova
2020 Fundamenta Mathematicae  
Kjuchukova's Ξp invariant gives a ribbon obstruction for Fox p-colored knots. The invariant is derived from dihedral branched covers of 4-manifolds, and can be used to calculate the signatures of these covers when singularities on the branching sets are present. In this note, we give an algorithm for evaluating Ξp from a colored knot diagram, and compute a couple of examples. 2020 Mathematics Subject Classification: Primary 57M12; Secondary 57K10, 57N70.
doi:10.4064/fm767-7-2020 fatcat:toxoqwmqfvb4dfe7bbs7djpo6q