Ganea fibrations. (Fibrations à la Ganea.)
Generalized symmetric spaces and minimal models
We prove that any compact simply connected manifold carrying a structure of Riemannian 3- or 4-symmetric space is formal in the sense of Sullivan. This result generalizes Sullivan's classical theorem on the formality of symmetric spaces, but the proof is of a different nature, since for generalized symmetric spaces techniques based on the Hodge theory do not work. We use the Thomas theory of minimal models of fibrations and the classification of 3- and 4-symmetric spaces.
Genus sets and SNT sets of certain connective covering spaces
We study the genus and SNT sets of connective covering spaces of familiar finite CW-complexes, both of rationally elliptic type (e.g. quaternionic projective spaces) and of rationally hyperbolic type (e.g. one-point union of a pair of spheres). In connection with the latter situation, we are led to an independently interesting question in group theory: if f is a homomorphism from Gl(ν,A) to Gl(n,A), ν < n, A = ℤ, resp. , does the image of f have infinite, resp. uncountably infinite, index in...
Graded Lie Algebras of depth one.
Graded Lie algebras with finite polydepth
Growth and Lie brackets in the homotopy Lie algebra.