Fusion of boundary surface-link and ribbonness
arXiv:2507.18154
Abstract
A boundary surface-link in the 4-sphere is proved to be a ribbon surface-link if the surface-link obtained from it by surgery along a pairwise surgically nontrivial fusion 1-handle system is a ribbon surface-link.
A clearer definition on a fusion 1-handle of boundary surface-link is done. Positive answer to Cochran's conjecture and the other results are moved into the paper "Quasi-ribbon but non-ribbon surface-link of trivial components"