An Algebraic Model for G-Simple Homotopy Types.
An elementary proof of a Lima's theorem for surfaces.
An elementary proof of the following theorem is given:THEOREM. Let M be a compact connected surface without boundary. Consider a C∞ action of Rn on M. Then, if the Euler-Poincaré characteristic of M is non zero there exists a fixed point.
An Equivariant Extension Theorem and G-Retracts with a Finite Structure.
An Equivariant Lefschetz Formula for Finite Reductive Groups.
An introduction to spherical orbit spaces.
An -equivariant degree and the Fuller index
Analysis on real affine -varieties.
Analytische periodische Strömungen auf kompakten komplexen Räumen.
Anosov theorem for coincidences on nilmanifolds
Suppose that L, L’ are simply connected nilpotent Lie groups such that the groups and in their lower central series have the same dimension. We show that the Nielsen and Lefschetz coincidence numbers of maps f,g: Γ∖L → Γ’∖L’ between nilmanifolds Γ∖L and Γ’∖L’ can be computed algebraically as follows: L(f,g) = det(G⁎ - F⁎), N(f,g) = |L(f,g)|, where F⁎, G⁎ are the matrices, with respect to any preferred bases on the uniform lattices Γ and Γ’, of the homomorphisms between the Lie algebras , ’ of...
Äquivariante 2-Felder auf Mannigfaltigkeiten mit Involution.
Äquivariante Homotopie, äquivarianter Bordismus und freie differenzierbare Involutionen auf Sphären.
Area preserving group actions on surfaces.
Area preserving twist homeomorphism of the annulus.
Asymptotic Properties of Foliations
Au bord de certains polyèdres hyperboliques
Le cadre de cet article est celui des groupes et des espaces hyperboliques de M. Gromov. Il est motivé par la question suivante : comment différencier deux groupes hyperboliques à quasi-isométrie près ? On illustre ce problème en détaillant un exemple de M. Gromov issu de Asymptotic invariants for infinite groups. On décrit une famille infinie de groupes hyperboliques, deux à deux non quasi-isométriques, de bord la courbe de Menger. La méthode consiste à étudier leur structure quasi-conforme au...
Automorphism Groups of Second Order Differential Equations.