Weak cofibrations in categories of cofibrant objects.
Weak equivalence classes of complex vector bundles.
Weak homotopy equivalences of mapping spaces and Vogt's lemma
Weak subobjects and weak limits in categories and homotopy categories
Weak Wecken's theorem for periodic points in dimension 3
We prove that a self-map f: M → M of a compact PL-manifold of dimension ≥ 3 is homotopic to a map with no periodic points of period n iff the Nielsen numbers for k dividing n all vanish. This generalizes the result from [Je] to dimension 3.
Weakly additive cohomology.
In this paper the concept of weakly additive cohomology theory is introduced as a variant of the known concept of additive cohomology theory. It is shown that for a closed A in X the singular homology of the pair (X, X-A) (with some fixed cohomology group) regarded as a furcter of A is a weakly additive cohomology theory on any collectionwise normal space X. Furthermore, every compactly supported cohomology theory is weakly additive.The main result is a comparison theorem for two cohomology theories...
Wecken theorems for Nielsen intersection theory
Nielsen theory, originally developed as a homotopy-theoretic approach to fixed point theory, has been translated and extended to various other problems, such as the study of periodic points, coincidence points and roots. Recently, the techniques of Nielsen theory have been applied to the study of intersections of maps. A Nielsen-type number, the Nielsen intersection number NI(f,g), was introduced, and shown to have many of the properties analogous to those of the Nielsen fixed point number. In particular,...
Wecken type problems for self-maps of the Klein bottle.
Wedge cancellation and genus.
Wedge cancellation of certain mapping cones
Weighted cohomology.
Weights in cohomology and the Eilenberg-Moore spectral sequence
We show that in the category of complex algebraic varieties, the Eilenberg–Moore spectral sequence can be endowed with a weight filtration. This implies that it degenerates if all spaces involved have pure cohomology. As application, we compute the rational cohomology of an algebraic -variety ( being a connected algebraic group) in terms of its equivariant cohomology provided that is pure. This is the case, for example, if is smooth and has only finitely many orbits. We work in the category...
When are Topologically Equivalent Orthogonal Transformations Linearly Equivalent?
When projective does not imply flat, and other homological anomalies.
Which 3-manifold groups are Kähler groups?
The question in the title, first raised by Goldman and Donaldson, was partially answered by Reznikov. We give a complete answer, as follows: if can be realized as both the fundamental group of a closed 3-manifold and of a compact Kähler manifold, then must be finite—and thus belongs to the well-known list of finite subgroups of , acting freely on .
Whitehead Torsions Vanish in Many S1 Bundles.
Whitehead transfers for S1-bundles, an algebraic description.
Whitney continua of graphs admit all homotopy types of compact connected ANRs
Whitney-Cartan Product Formulae.
Winding Numbers on Surfaces, I.