Handle-decompositions of -manifolds
Hardness of embedding simplicial complexes in
Let be the following algorithmic problem: Given a finite simplicial complex of dimension at most , does there exist a (piecewise linear) embedding of into ? Known results easily imply polynomiality of (; the case is graph planarity) and of for all . We show that the celebrated result of Novikov on the algorithmic unsolvability of recognizing the 5-sphere implies that and are undecidable for each . Our main result is NP-hardness of and, more generally, of for all , with...
Hauptvermutung et triangulation des variétés
h-Cobordismes entre variétés homéomorphes.
h-cobordisms between 1-connected 4-manifolds.
Heegaard and regular genus of 3-manifolds with boundary.
By means of branched coverings techniques, we prove that the Heegaard genus and the regular genus of an orientable 3-manifold with boundary coincide.
Heegaard splittings of Seifert fibered spaces.
Heegaard splittings of (surface) x I are standars.
Heegard and regular genus agree for compact -manifolds
Hermitian forms on link modules.
High-dimensional knots corresponding to the fractional Fibonacci groups
We prove that the natural HNN-extensions of the fractional Fibonacci groups are the fundamental groups of high-dimensional knot complements. We also give some characterization and interpretation of these knots. In particular we show that some of them are 2-knots.
Higher dimensional simple knots and minimal Seifert surfaces.
Homogeneity of dynamically defined wild knots.
In this paper we prove that a wild knot K which is the limit set of a Kleinian group acting conformally on the unit 3-sphere, with its standard metric, is homogeneous: given two points p, q ∈ K, there exists a homeomorphism f of the sphere such that f(K) = K and f(p) = q. We also show that if the wild knot is a fibered knot then we can choose an f which preserves the fibers.
Homotopie des espaces de concordances
Homotopy characterization of weakly flat knots
Homotopy Lie algebras; lower central series and the Koszul property.
Homotopy type of automorphism groups of manifolds
Hyperspaces of CW-complexes
It is shown that the hyperspace of a connected CW-complex is an absolute retract for stratifiable spaces, where the hyperspace is the space of non-empty compact (connected) sets with the Vietoris topology.