On spaces of the same strong -type.
Growth and Lie brackets in the homotopy Lie algebra.
Rational homotopy of Serre fibrations
In rational homotopy theory, we show how the homotopy notion of pure fibration arises in a natural way. It can be proved that some fibrations, with homogeneous spaces as fibre are pure fibrations. Consequences of these results on the operation of a Lie group and the existence of Serre fibrations are given. We also examine various measures of rational triviality for a fibration and compare them with and whithout the hypothesis of pure fibration.
The Formal Dimension of a Toplogical Space.
Module d'holonomie d'une fibration
Effet d'un attachement cellulaire dans l'homologie de l'espace des lacets
Un des problèmes historiques de la théorie homotopique des espaces est de mesurer l’effet de l’attachement d’une cellule au niveau des groupes d’homotopie. Le problème de l’attachement inerte reste en particulier un problème ouvert. Nous donnons ici une réponse partielle à ce problème.
Homologie des espaces de lacets des espaces de configuration
Nous calculons dans ce texte l’homologie de l’espace des lacets de l’espace des configurations ordonnées de points dans une variété compacte simplement connexe .
Rational BV-algebra in string topology
Let be a 1-connected closed manifold of dimension and be the space of free loops on . M.Chas and D.Sullivan defined a structure of BV-algebra on the singular homology of , . When the ring of coefficients is a field of characteristic zero, we prove that there exists a BV-algebra structure on the Hochschild cohomology which extends the canonical structure of Gerstenhaber algebra. We construct then an isomorphism of BV-algebras between and the shifted homology . We also prove that the...
Nilpotent subgroups of the group of fibre homotopy equivalences.
Let ξ = (E, p, B, F) be a Hurewicz fibration. In this paper we study the space L(ξ) consisting of fibre homotopy self equivalences of ξ inducing by restriction to the fibre a self homotopy equivalence of F belonging to the group G. We give in particular conditions implying that π(L(ξ)) is finitely generated or that L(ξ) has the same rational homotopy type as aut(F).
The Hochschild cohomology of a closed manifold
Let M be a closed orientable manifold of dimension and be the usual cochain algebra on M with coefficients in a field. The Hochschild cohomology of M, is a graded commutative and associative algebra. The augmentation map induces a morphism of algebras . In this paper we produce a chain model for the morphism I. We show that the kernel of I is a nilpotent ideal and that the image of I is contained in the center of , which is in general quite small. The algebra is expected to be isomorphic...
The homotopy Lie algebra for finite complexes
L. S. catégorie et suite spectrale de Milnor-Moore. (Une nuit dans le train)
Sur certaines algèbres de Lie de dérivations
Il est démontré que toute a.d.g.c. ayant un modèle minimal de Sullivan de type fini peut être représentée par une certaine algèbre de Lie différentielle graduée de dérivations. En particulier on peut ainsi représenter le type d’homotopie rationnelle d’un espace topologique.
Graded Lie algebras with finite polydepth
Rational string topology
We use the computational power of rational homotopy theory to provide an explicit cochain model for the loop product and the string bracket of a simply connected closed manifold . We prove that the loop homology of is isomorphic to the Hochschild cohomology of the cochain algebra with coefficients in . Some explicit computations of the loop product and the string bracket are given.
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