The topology of toric varieties

We construct orientations on moduli spaces of pseudoholomorphic quilts with seam conditions in Lagrangian correspondences equipped with relative spin structures and determine the effect of various gluing operations on the orientations. We also investigate the behavior of the orientations under composition of Lagrangian correspondences.

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Orientations for pseudoholomorphic quilts

We use Lefschetz pencil methods to derive structural results about Fukaya categories of Calabi-Yau hypersurfaces; in particular, concerning their dependence on the Novikov parameter. Warning to the reader: the arguments in this paper cite two preprints (papers 6.5 and 7 in the series) which do not at present exist. Until that is remedied, the proofs cannot be considered complete, and this paper should be regarded as a preliminary research announcement.

Fukaya A_\infty-structures associated to Lefschetz fibrations. III

We investigate the relations between algebraic structures, spectral invariants, and persistence modules, in the context of monotone Lagrangian Floer homology with Hamiltonian term. Firstly, we use the newly introduced method of filtered continuation elements to prove that the Lagrangian spectral norm controls the barcode of the Hamiltonian perturbation of the Lagrangian submanifold, up to shift, in the bottleneck distance. Moreover, we show that it satisfies Chekanov type low-energy intersection phenomena, and non-degeneracy theorems. Secondly, we introduce a new averaging method for bounding the spectral norm from above, and apply it to produce precise uniform bounds on the Lagrangian spectral norm in certain closed symplectic manifolds. Finally, by using the theory of persistence modules, we prove that our bounds are in fact sharp in some cases. Along the way we produce a new calculation of the Lagrangian quantum homology of certain Lagrangian submanifolds, and answer a question of Usher.

Bounds on spectral norms and barcodes

The wall-crossing formula and Lagrangian mutations

We incorporate pearly Floer trajectories into the tranversality scheme for pseudoholomorphic maps introduced by Cieliebak–Mohnke (J Symplectic Geom 5(3): 281–356, 2007). By choosing generic domain-dependent almost complex structures, we obtain zero- and one-dimensional moduli spaces with the structure of cell complexes with rational fundamental classes. Integrating over these moduli spaces gives a definition of Floer cohomology over Novikov rings via stabilizing divisors for rational Lagrangians that are fixed point sets of anti-symplectic involutions satisfying certain Maslov index conditions as well as Hamiltonian Floer cohomology of compact rational symplectic manifolds.

Floer trajectories and stabilizing divisors

We show that blow-ups or reverse flips (in the sense of the minimal model program) of rational symplectic manifolds with point centers create Floer-non-trivial Lagrangian tori. As applications, we demonstrate the existence of Hamiltonian non-displaceable Lagrangian tori in, for example, small symplectic blow-ups of compact symplectic manifolds and moduli spaces of polygons. These results are part of a conjectural description of generators for the Fukaya category of a compact symplectic manifold with a singularity-free running of the minimal model program.

Floer theory and flips

We define objects made of marked complex disks connected by metric line segments and construct nonsymmetric and symmetric moduli spaces of these objects. This allows choices of coherent perturbations over the corresponding versions of the Floer trajectories proposed by Cornea and Lalonde. These perturbations are intended to lead to an alternative description of the (obstructed) $A_\infty$-structures studied by Fukaya, Oh, Ohta and Ono. 
Given a $Pin_{\pm}$ monotone lagrangian submanifold $L \subset (M,\omega)$ with minimal Maslov number $N_L \geq 2$, we define an $A_\infty$-algebra (resp. differential graded algebra) structure from the critical points of a generic Morse function on $L$. It is written as a cochain (resp. chain) complex extending the pearl complex introduced by Oh and further explicited by Biran and Cornea, equipped with its quantum product. We verify that the construction is homotopy invariant, defining a functor from a homotopy category of $Pin_{\pm}$ monotone lagrangian submanifolds $h\mathcal{L}^{mono, \pm}(M,\omega)$ to the homotopy category of cochain (resp. chain) complexes $hK(\Lambda \text{-mod})$ where $\Lambda$ is a Novikov ring with coefficients in $\mathbb{Z}$.

Source spaces and perturbations for cluster complexes

We use the technique of stabilizing divisors introduced by Cieliebak-Mohnke to construct finite dimensional, strictly unital Fukaya algebras of compact, oriented, relatively spin Lagrangians in compact symplectic manifolds with rational symplectic classes. The homotopy type of the algebra and the moduli space of solutions to the weak Maurer-Cartan equation are shown to be independent of the choice of perturbation data. The Floer cohomology is the cohomology of a complex of vector bundles over the space of solutions to the weak Maurer-Cartan equation and is shown to be independent of the choice of perturbation data up to gauge equivalence.

Fukaya algebras via stabilizing divisors

We incorporate pearly Floer trajectories into the transversality scheme for pseudoholomorphic maps introduced by Cieliebak-Mohnke. By choosing generic domain-dependent almost complex structures we obtain zero and one-dimensional moduli spaces with the structure of cell complexes with rational fundamental classes. This gives a definition of Floer cohomology over Novikov rings via stabilizing divisors for compact symplectic manifolds with rational symplectic classes and Lagrangians that are fixed point sets of anti-symplectic involutions satisfying certain Maslov index conditions, in particular, Hamiltonian Floer cohomology.

François Charest

Papers

Floer trajectories and stabilizing divisors

Floer theory and flips

Source spaces and perturbations for cluster complexes

Fukaya algebras via stabilizing divisors

Floer trajectories and stabilizing divisors