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**Séance du Vendredi 5 octobre 2012.**

Lieu: IHP, Salle 201.

- 11h: Rémi Leclercq (Université Paris Sud),

*Uniqueness of continuous Hamiltonians*

- 14h: Oliver Fabert (Université de Freiburg),

*New algebraic structures in Floer theory*

*Connecting orbits for family of Tonelli Hamiltonians*

Résumés

*:*

11h: Rémi Leclercq:

*Uniqueness of continuous Hamiltonians*
I will consider limits of Hamiltonian flows for the spectral and
Hofer's distances. Namely, I will show that a continuous function
obtained as a uniform limit of smooth Hamiltonians whose flows
converge to the identity must vanish. As a key-step of the proof, I
will first establish a new energy-capacity-type inequality relating
Oh-Schwarz spectral invariants and the Hofer-Zehnder capacity.
Finally, I will explain some consequences of the main result in
C

^{^0}-symplectic topology. This is joint work with Vincent Humilière and Sobhan Seyfaddini.
14h: Oliver Fabert:

*New algebraic structures in Floer theory*
Floer cohomology for symplectomorphisms with its pair-of-pants product
can be viewed as a generalization of the small quantum cohomology
ring. In my talk I will show how the rich algebraic structures of
rational Gromov-Witten theory beyond the small quantum product
translate to the Floer theory of a symplectomorphism. In order to
define a big version of the pair-of-pants product, the corresponding
generalization of Frobenius manifolds and the resulting integrable
systems, I make use of the rich algebraic structures from rational
symplectic field theory. As an application of these new algebraic
structures in Floer theory, I prove a new big product axiom for the
Oh-Schwarz spectral invariants, as well as a new axiom involving the
Gromov-Witten integrable hierarchy. Finally I sketch how
transversality is established without polyfolds.

16h: Vito Mandorino:

*Connecting orbits for family of Tonelli Hamiltonians*

Let M be a compact manifold without boundary. We consider the dynamical
system generated by the time-one maps of a family of one-periodic Tonelli
(or optical) Hamiltonians on T*M.
Such a system is also called à polysystem.
By using the variational framework of weak KAM theory, we try to construct
orbits exhibiting some prescribed qualitative behaviors, such as
connecting orbits between two different, far apart regions of T*M. This
is related to the phenomenon of Arnold diffusion in near-integrable
Hamiltonian systems, and generalize some results of Moeckel and Le Calvez
for a family of exact-symplectic twist maps on the cylinder.