A Semigroup of Simple Homotopy Types.
A Spectral Sequence Concerning the Double Suspension.
A splitting theorem for connected Morava k-theories.
A suspension spectral sequence for vn-periodic homotopy groups.
A suspension theorem for the proper homotopy and strong shape theories
A topological version of Bertini's theorem
We give a topological version of a Bertini type theorem due to Abhyankar. A new definition of a branched covering is given. If the restriction of the natural projection π: Y × Z → Y to a closed set V ⊂ Y × Z is a branched covering then, under certain assumptions, we can obtain generators of the fundamental group π₁((Y×Z).
A Whitehead product for track groups (II).
Two direct relations are exhibited between the Whitehead product for track groups studied in [4] and the generalized Whitehead product in the sense of Arkowitz. The problem of determining the order of the Whitehead square is posed and some computations given.
A Whitehead theorem in CG-shape
Actions and automorphisms of crossed modules
Adams and Steenrod operators in dihedral homology.
Adjunction of n-equivalences and triad connectivity.
We prove a new adjunction theorem for n-equivalences. This theorem enables us to produce a simple geometric version of proof of the triad connectivity theorem of Blakers and Massey. An important intermediate step is a study of the collapsing map S∨X → S, S being a sphere.
Algebraic colimit calculations in homotopy theory using fibred and cofibred categories.
Algebraic homotopy classes of rational functions
Let be a field. We compute the set ofnaivehomotopy classes of pointed -scheme endomorphisms of the projective line . Our result compares well with Morel’s computation in [11] of thegroup of -homotopy classes of pointed endomorphisms of : the set admits an a priori monoid structure such that the canonical map is a group completion.
Algebraic topology for proper shape theory
Allgemeine Lage und äquivariante Homotopie.
An Arithmetic Characterization of the Rational Homotopy Groups of Certain Spaces.
An exact sequence from the nth to the (n-1)-st fundamental group
An isomorphism theorem of Hurewicz type in the proper homotopy category
Äquivalenzen bezüglich allgemeiner Homotopiegruppen.
Belts and k-invariants of link maps in spheres.