The Characteristic Toric Splitting of Irreducible Compact 3-Orbifolds.
The Classification of Maps of Nonorietable Surfaces.
The classiflcation of maps of surfaces.
The Homology of Cyclic and Irregular Dihedral Coverings Branched Over Homology Spheres.
The homology of irregular dihedral branched covers of S3.
The minimizing of the Nielsen root classes
Given a map f: X→Y and a Nielsen root class, there is a number associated to this root class, which is the minimal number of points among all root classes which are H-related to the given one for all homotopies H of the map f. We show that for maps between closed surfaces it is possible to deform f such that all the Nielsen root classes have cardinality equal to the minimal number if and only if either N R[f]≤1, or N R[f]>1 and f satisfies the Wecken property. Here N R[f] denotes the Nielsen...
The ?-orbifold Group of a Link.
The Whitehead link, the Borromean rings and the knot 946 are universal.
A link L in S3 is universal if every closed, orientable 3-manifold is a covering of S3 branched over L. Thurston [1] proved that universal links exist and he asked if there is a universal knot, and also if the Whitehead link and the Figure-eight knot are universal. In [2], [3] we answered the first question by constructing a universal knot. The purpose of this paper is to prove that the Whitehead link and the Borromean rings, among others, are universal. The question about the Figure-eight knot...
Torus knots and Dunwoody manifolds.
Two-fold branched coverings of S3 have type six.
In this work, we prove that every closed, orientable 3-manifold M3 which is a two-fold covering of S3 branched over a link, has type six.