Stability of Critical Points under Small Perturbations. Part I: Topological Theory.
Steenrod's Equivariant Moore Space Problem for Cohomologically Trivial Modules.
Strong Cohomological Dimension
We characterize strong cohomological dimension of separable metric spaces in terms of extension of mappings. Using this characterization, we discuss the relation between strong cohomological dimension and (ordinal) cohomological dimension and give examples to clarify their gaps. We also show that if X is a separable metric ANR and G is a countable Abelian group. Hence for any separable metric ANR X.
Strong surjectivity of mappings of some 3-complexes into 3-manifolds
Let K be a CW-complex of dimension 3 such that H³(K;ℤ) = 0, and M a closed manifold of dimension 3 with a base point a ∈ M. We study the problem of existence of a map f: K → M which is strongly surjective, i.e. such that MR[f,a] ≠ 0. In particular if M = S¹ × S² we show that there is no f: K → S¹ × S² which is strongly surjective. On the other hand, for M the non-orientable S¹-bundle over S² there exists a complex K and f: K → M such that MR[f,a] ≠ 0.
Strong surjectivity of mappings of some 3-complexes into
Let K be a CW-complex of dimension 3 such that H 3(K;ℤ) = 0 and the orbit space of the 3-sphere with respect to the action of the quaternion group Q 8 determined by the inclusion Q 8 ⊆ . Given a point a ∈ , we show that there is no map f:K → which is strongly surjective, i.e., such that MR[f,a]=min(g −1(a))|g ∈ [f] ≠ 0.
Strong surjectivity of maps from 2-complexes into the 2-sphere
Given a model 2-complex K P of a group presentation P, we associate to it an integer matrix ΔP and we prove that a cellular map f: K P → S 2 is root free (is not strongly surjective) if and only if the diophantine linear system ΔP Y = (f) has an integer solution, here (f)is the so-called vector-degree of f
Strongly homotopically stabile points
Subspace and addition theorems for extension and cohomological dimensions. A problem of Kuzminov
Suites Fσ -absorbantes en théorie de la dimension
Suites spectrales de Hochschild-Serre à coefficients dans un espace semi-normé.
In this paper, we prove the existence of the theory of spectral sequences in the category of real semi normed spaces. Using this theory, we associate to any extension of discrete groups the Hochschild-Serre spectral sequence in bounded cohomology with coefficients. In addition, we give the explicit expression of the first and the second term of this spectral sequence without further hypothesis.
Superextensions and Lefschetz fixed point structures
Sur la catégorie de Lusternik-Schnirelmann des algèbres de cochaînes
Nous introduisons une nouvelle définition d’un invariant bicat pour une algèbre de cochaînes connexe et 1-connexe, de type fini sur un corps de caractéristique quelconque, et nous montrons d’une part, qu’il coïncide avec l’invariant cat introduit par S. Halperin et J.-M. Lemaire et d’autre part, qu’il est invariant par extension de corps et qu’il vérifie la conjecture de Ganéa.
Sur la dualité de Poincaré.
Sur les invariants d'homotopie rationnelle liés à la L.S. catégorie.
Symmetrie Products of ANR's.