Homotopy groups of diagonal complements

Higher Homotopy Groups of Complements of Complex Hyperplane Arrangements

We generalize results of Hattori on the topology of complements of hyperplane arrangements, from the class of generic arrangements, to the much broader class of hypersolvable arrangements. We show that the higher homotopy groups of the complement vanish in a certain combinatorially determined range, and we give an explicit Zπ1-module presentation of πp, the first non-vanishing higher homotopy g...

Hypersurface complements , Milnor fibers and higher homotopy groups of arrangments

Maximal complements in finite groups

Let G be a finite group with a non-abelian minimal normal subgroup N which is a direct product of the simple group X. The maximal subgroups of G which complement N and their conjugacy classes are parametrised in terms of certain homomorphisms taking values in AutX and satisfying particular conditions.

Homotopy Groups of Compact Abelian Groups

Preliminaries. Bn (resp. 5„_i) will denote the subset of Rn consisting of those x such that ||x|| g 1 (resp. ¡|x|| = 1). x0 will denote the point (1, 0, 0, •• -, 0) of R" and T will denote Si made into a topological group by using complex multiplication. All groups will be assumed to be Abelian. For a based topological space X and a topological group G, let C(X, G) denote the set of maps (i.e.,...

On 2-Dimensional Homotopy Invariants of Complements of Knotted Surfaces

We prove that ifM is a compact 4-manifold provided with a handle decomposition with 1-skeleton X , and if G is a finite crossed module, then the number of crossed module morphisms from the fundamental crossed module Π2(M,X , ∗) = (π1(X , ∗), π2(M,X , ∗), ∂, ⊲) into G can be re-scaled to a manifold invariant IG (i. e. not dependent on the choice of 1-skeleton), a construction similar to David Ye...