Norio Iwase

Mailing Adress: Faculty of Mathematics, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan
E-mail Adress: iwase_AT__AT_math.kyushu-u.ac.jp

Japanese

Authors.
myself
Journal.
Topology, to appear.
Abstract.
Berstein-Hilton Hopf invariants are generalised to detect the higher homotopy associativity of a Hopf space as `higher Hopf invariants', which are studied as obstructions for normalised Lusternik-Schnirelmann category, LS category for short. Under a condition among dimension and LS category, the criterion for Ganea's conjecture on LS category is obtained using the stabilised higher Hopf invariants and the conjecture in "Ganea's conjecture on Lusternik-Schnirelmann category" is verified, which yields the main result in it except the case when p=2. As an application, conditions in terms of homotopy invariants of the attaching maps are given to determine LS category of sphere-bundles-over-spheres: A closed manifold is found to have the same LS category as its punctured submanifold and another closed manifold is found not to satisfy Ganea's conjecture on LS category.

A-method in LS-category (adobe-pdf file, 238071 bytes)