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Subgroups of continuous groups acting differentiably on the half-line

Joseph F. Plante (1984)

Annales de l'institut Fourier

We consider groups of diffeomorphisms of the closed half-line which fix only the end point. When the group is a Lie group it is isomorphic to a subgroup of the affine group. On the other hand, when the group is isomorphic to a discrete subgroup of a solvable Lie group it is topologically equivalent to a subgroup of the affine group.

Submanifolds of codimension two and homology equivalent manifolds

Sylvain E. Cappell, Julius L. Shaneson (1973)

Annales de l'institut Fourier

In this paper new methods of studying codimension two embeddings of manifolds are outlined. Results are stated on geometric periodicity of knot cobordism. The group of local knots of a manifold in a 2-plane bundle is introduced and computed, and applied to C o -close embeddings. General codimension two splitting theorems are discussed, with applications to equivariant knots and knot cobordism. A general existence theorem for P.L. (non-locally flat) embeddings is also given.The methods involve some...

Sur la densité des systèmes de Pfaff sans solution algébrique

Luis G. Mendes, Marcos Sebastiani (1994)

Annales de l'institut Fourier

On démontre que dans toute surface rationnelle, non-isomorphe au plan projectif, il existe une feuilletage analytique rigide, possédant des feuilles algébriques et n’ayant que des singularités isolées.

Sur la géométrie transverse des feuilletages

Pierre Molino (1975)

Annales de l'institut Fourier

On introduit une relation d’équivalence entre feuilletages ayant la même géométrie transverse. La notion de feuilletage ( F -variété) est obtenue en utilisant comme modèles locaux les espaces quotients de feuilletages, modulo cette relation d’équivalence. On étudie brièvement les feuillages du point de vue différentiable.

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