A characterization of certain branched coverings as group actions
A class of discriminant varieties in the conformal 3-sphere.
A classification of cohomology transfers for ramified covering maps
We construct a cohomology transfer for n-fold ramified covering maps. Then we define a very general concept of transfer for ramified covering maps and prove a classification theorem for such transfers. This generalizes Roush's classification of transfers for n-fold ordinary covering maps. We characterize those representable cofunctors which admit a family of transfers for ramified covering maps that have two naturality properties, as well as normalization and stability. This is analogous to Roush's...
A note on irreducible Heegaard diagrams.
A topological version of Bertini's theorem
We give a topological version of a Bertini type theorem due to Abhyankar. A new definition of a branched covering is given. If the restriction of the natural projection π: Y × Z → Y to a closed set V ⊂ Y × Z is a branched covering then, under certain assumptions, we can obtain generators of the fundamental group π₁((Y×Z).
A universal class of 4-colored graphs.
About some infinite family of 2-bridge knots and 3-manifolds.
Actions of on some surface-bundles over
Around the Borromean link.
This is a survey of some consequences of the fact that the fundamental group of the orbifold with singular set the Borromean link and isotropy cyclic of order 4 is a universal kleinian group.