Homoclinic Floer homology via direct limits

Abstract: Let $(M \omega)$ be a two dimensional symplectic manifold, $\phi: M \to M$ a symplectomorphism with hyperbolic fixed point $x$ and transversely intersecting stable and unstable manifolds $W^s(\phi, x) \cap\ W^u(\phi, x)=:\mathcal{H}(\phi, x)$. The intersection points are called homoclinic points, and the stable and unstable manifold are in this situation Lagrangian submanifolds. For this Lagrangian intersection problem with its infinite number of intersection points and wild oscillation behavior, we first define a Floer homology generated by finite sets of so-called contractible homoclinic points. This generalizes very significantly the Floer homologies generated by (semi)primary points defined by us in earlier works. Nevertheless these Floer homologies only consider quite local' aspects of $W^s(\phi, x) \cap\ W^u(\phi, x)$ since their generator sets are finite, but the number of all contractible homoclinic points is infinite. To overcome this issue, we construct a direct limit of theselocal' homoclinic Floer homologies over suitable index sets. These direct limits thus accumulate the information gathered by the finitely generated local' homoclinic Floer homologies.