Some results concerning the number of critical points of a smooth map.
Spaces whose only finite-sheeted covers are themselves. I.
Submersions sur le cercle
Sur les étalements ramifiés de surfaces
Surgeries on small volume hyperbolic 3-orbifolds.
Surgery and involutions on 4-manifolds.
Systolic groups acting on complexes with no flats are word-hyperbolic
We prove that if a group acts properly and cocompactly on a systolic complex, in whose 1-skeleton there is no isometrically embedded copy of the 1-skeleton of an equilaterally triangulated Euclidean plane, then the group is word-hyperbolic. This was conjectured by D. T. Wise.
The covering semigroup of invariant control systems on Lie groups
It is well known that the class of invariant control systems is really relevant both from theoretical and practical point of view. This work was an attempt to connect an invariant systems on a Lie group with its covering space. Furthermore, to obtain algebraic properties of this set. Let be a Lie group with identity and a cone in the Lie algebra of that satisfies the Lie algebra rank condition. We use a formalism developed by Sussmann, to obtain an algebraic structure on the covering...
The Degree and Branch Set of a Branched Covering.
The fundamental group and Galois coverings of hexagonal systems in 3-space.
The fundamental group and the spectrum of the Laplacian.
The Hurwitz Relation for Tori.
The ...-injectivity of self-maps of nonzero degree on 3-manifolds.
The virtual Haken conjecture: Experiments and examples.
Topological geodesics and virtual rigidity.
Topology of Finite Graphs.
Totally Real Imbeddings and the Universal Covering Spaces of Domains of Holomorphy: Some Examples.
Ultra regular covering space and its automorphism group
In order to classify digital spaces in terms of digital-homotopic theoretical tools, a recent paper by Han (2006b) (see also the works of Boxer and Karaca (2008) as well as Han (2007b)) established the notion of regular covering space from the viewpoint of digital covering theory and studied an automorphism group (or Deck's discrete transformation group) of a digital covering. By using these tools, we can calculate digital fundamental groups of some digital spaces and classify digital covering spaces...
Verschlingungsinvarianten von Knoten und Verkettungen mit zwei Brücken.
Virtual Betti numbers of genus 2 bundles.