Invariant Seifert surfaces for strongly invertible knots
Invariant Seifert surfaces for strongly invertible knots
We study invariant Seifert surfaces for strongly invertible knots, and prove that the gap between the equivariant genus (the minimum of the genera of invariant Seifert surfaces) of a strongly invertible knot and the (usual) genus of the underlying knot can be arbitrarily large. This forms a sharp contrast with …