Local homotopy products
When localizing the semidirect product of two groups, the effect on the factors is made explicit. As an application in Topology, we show that the loop space of a based connected CW-complex is a P-local group, up to homotopy, if and only if π1X and the free homotopy groups [Sk-1, ΩX], k ≥ 2, are P-local.
We describe an obstruction theory for an H-space X to be a loop space, in terms of higher homotopy operations taking values in . These depend on first algebraically “delooping” the Π-algebras , using the H-space structure on X, and then trying to realize the delooped Π-algebra.
We study the Lusternik-Schnirelmann category of some CW-complexes with 3 cells, built on Y = S2n Uk[i2n,i2n] e4n. In particular, we prove that an R-local space, in the sense of D. Anick, of LS-category 3 and of the homotopy type of a CW-complex with 3 R-cells, has a cup-product of length 3 in its algebra of cohomology. This result is no longer true in the framework of mild spaces.