R-Acyclicité.
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...
Rational category of the space of sections of a nilpotent bundle.
Rational Co-H-Spaces.
Rational evalutation subgroups.
Rational fibrations homogeneous spaces with positive Euler characteristics and Jacobians
We show that an orientable fibration whose fiber has a homotopy type of homogeneous space with rank is totally non homologous to zero for rational coefficients. The Jacobian formed by invariant polynomial under the Weyl group of plays a key role in the proof. We also show that it is valid for mod. coefficients if does not divide the order of the Weyl group of .
Rational fibrations in differential homological algebra.
Rational formality of function spaces.
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.
Rational Hopf G-spaces with two nontrivial homotopy group systems
Let G be a finite group. We prove that every rational G-connected Hopf G-space with two nontrivial homotopy group systems is G-homotopy equivalent to an infinite loop G-space.
Rational Lie Algebras and p-Isomorphisms of Nilpotent Groups and Homotopy Types.
Rational models of solvmanifolds with Kählerian structures.
We investigate the existence of symplectic non-Kählerian structures on compact solvmanifolds and prove some results which give strong necessary conditions for the existence of Kählerian structures in terms of rational homotopy theory. Our results explain known examples and generalize the Benson-Gordon theorem (Benson and Gordon (1990); our method allows us to drop the assumption of the complete solvability of G).
Rational nilpotent groups as subgroups of self-homotopy equivalences
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.
Rational toral ranks in certain algebras.
Rationale Homotopietypen.
Rationalization of Hopf G-Spaces..
Real cobordism and greek letter elements in the geometric chromatic spectral sequence.
Real Homotopy Theory of Kähler Manifolds.
Realization Problems for the Group of Homotopy Classes of Self-Equivalences.