1,354,859 research outputs found
A geometric formula for Haefliger knots
No full textAbstractHaefliger has shown that a smooth embedding of the (4k−1)-sphere in the 6k-sphere can be knotted in the smooth sense. In this paper, we give a formula with which we can detect the isotopy class of such a Haefliger knot. The formula is expressed in terms of the geometric characteristics of an extension, analogous to a Seifert surface, of the given embedding. In particular, the Hopf invariant associated to the extension plays a crucial role. This leads us to a new characterisation of Haefliger knots
Transversal topology and singularities of Haefliger foliations
No full textIn order to study singularities of Haefliger foliation, we define the notion of transversally Whitney C∞-topology modulo a regular foliation on the set of C∞-mappings into a foliated manifold. We prove a kind of transversaHty theorem with respect to this new topology. All arguments we use here are analogous to those· of the theory for the ordinary Whitney C∞-topology. However, this is the first attempt for the study of generic properties of Haefliger foliation
Haefliger structures and linear homotopy
No full textThe notion of linear-homotopy into a classifying space is introduced and used to give a precise classification of Haefliger structures. Appendix on the product theorem for simplicial spaces and realizations of bisimplicial spaces.</p
The periphery on stage: the intra-organizational dynamics in online communities of creation
No full textThis paper theorizes the intra-organizational dynamics of online communities of creation such as Free and Open Source software projects. It describes the role of the participants at the peripheries of these online communities and analyze how the division of labor among peripheral and core members is handled. The paper further demonstrates that this mode of labor division is possible only if the periphery is able to acquire and absorb the standards associated with the developers’ activities, described here as a social practice. We describe how the propagation of such standards takes place through non-material artifacts such as code and virtual discussions. We show that because of the capacity of these artifacts to effectively
disseminate the standards of a social practice, such standards can be transferred not only face to face,
but also asynchronously, asymmetrically and openly
L'influence française sur le thème de la Danse macabre avec figuration de pharmacien
No full textHaefliger L.-A. L'influence française sur le thème de la Danse macabre avec figuration de pharmacien. In: Revue d'histoire de la pharmacie, 24ᵉ année, n°96, 1936. pp. 393-401
Haefliger structures and symplectic/contact structures
No full textInternational audienceFor some geometries including symplectic and contact structures on an n-dimensional manifold, we introduce a two-step approach to Gromov's h-principle. From formal geometric data, the first step builds a transversely geometric Haefliger structure of codimension n. This step works on all manifolds, even closed. The second step, which works only on open manifolds and for all geometries, regularizes the intermediate Haefliger structure and produces a genuine geometric structure. Both steps admit relative parametric versions. The proofs borrow ideas from W. Thurston, like jiggling and inflation. Actually, we are using a more primitive jiggling due to R. Thom
Haefliger structures and symplectic/contact structures
No full textInternational audienceFor some geometries including symplectic and contact structures on an n-dimensional manifold, we introduce a two-step approach to Gromov's h-principle. From formal geometric data, the first step builds a transversely geometric Haefliger structure of codimension n. This step works on all manifolds, even closed. The second step, which works only on open manifolds and for all geometries, regularizes the intermediate Haefliger structure and produces a genuine geometric structure. Both steps admit relative parametric versions. The proofs borrow ideas from W. Thurston, like jiggling and inflation. Actually, we are using a more primitive jiggling due to R. Thom
Les grands pharmaciens : XVIII. F.-A. Flückiger (1828-1894)
No full textHaefliger Joseph-Antoine. Les grands pharmaciens : XVIII. F.-A. Flückiger (1828-1894). In: Bulletin de la Société d'histoire de la pharmacie, 16ᵉ année, n°58, 1928. pp. 46-50
Singularities of applications from R2 to R2 and Haefliger theorem
No full textBaseados nos trabalhos de Hasseler Whitney e Andrà Haefliger,
buscamos saber sobre que condiÃÃes uma aplicaÃÃo suave f : M → R2 de uma superfÃcie compacta no espaÃo R2 pode ser estudada como composiÃÃo de uma imersÃo g : M → R3 com a projeÃÃo natural п : R3→R2.Based on work of Hasseler Whitney and Andrà Haefliger
we seek to know under what conditions smooth application f : M → R2 of a compact surface in space R2 an be
studied as a composition of a immersion g : M → R3 with the natural projection п : R3 → R2
Un collectionneur Bâlois : Félix Platter : J. - A. Haefliger, Felix Platters Hausapotheke, in Basler Jahrbuch, 1939
No full textDelaunay Paul. Un collectionneur Bâlois : Félix Platter : J. - A. Haefliger, Felix Platters Hausapotheke, in Basler Jahrbuch, 1939. In: Revue d'histoire de la pharmacie, 35ᵉ année, n°119, 1947. pp. 251-252
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