A new obstruction for ribbon-moves of 2-knots: 2-knots fibred by the punctured 3-tori and 2-knots bounded by homology spheres

摘要

This paper gives a new obstruction for ribbon-move equivalence of 2-knots. Let $K$ and $K'$ be 2-knots. Let $K$ and $K'$ are ribbon-move equivalent. Onecorollary to our main theorem is as follows. A 2-dimensional fibered knot whosefiber is the punctured 3-dimensional torus is not ribbon-move equivalent to any2-dimensional knot whose Seifert hypersurface is a punctured homology sphere.