Unknotting surface links which are coverings of a trivial torus knot

Abstract

We consider surface links in the 4-space which are presented by the form of simple branched coverings over the standard torus, which we call torus-covering links. In this paper, we study unknotting numbers of torus-covering links. In some cases, we can determine the unknotting numbers.

arXiv commentThis paper has been withdrawn by the author. The result will be generalized in another paper