Equivalence of the pearly tree immersed Lagrangian Floer theory and the Hamiltonian immersed Lagrangian Floer theory
Zuyi Zhang
TL;DR
This work resolves an equivalence between immersed Lagrangian Floer theory formulated via pearly-tree discs and the Hamiltonian-perturbed immersed Floer theory in Weinstein neighborhoods. By extending the Alston–Bao framework to obstructed chain complexes, the authors show a canonical identification between the pearly-tree chain complex $ (\mathrm{CF}^P(L),\partial^P) $ defined by a Morse function on an immersion and the Hamiltonian chain complex $ (\mathrm{CF}^H(L,L_{\phi_\epsilon}),\partial^H) $ induced by a small local Hamiltonian flow, in both directions. The proof leverages a detailed analysis of $J$-holomorphic discs, a four-type classification of pearly-tree discs, and a key intermediate Hamiltonian $H_1$ to transport generators and boundary data across the two models, supported by a transversality/regularity framework and a Sard–Smale argument for families of Lagrangian immersions. The results unify two perspectives on immersed Lagrangian Floer theory, enabling computations via either pearly-trees or local Hamiltonian flows, with implications for the structure of the Fukaya category and potential mirror-symmetry applications.
Abstract
The goal of this paper is to prove an equivalence relation between the immersed Lagrangian Floer theory, defined using pearly tree discs, and local Hamiltonian flows, i.e., Hamiltonian flows performed in the Weinstein tubular neighborhood. This is a generalization of Alston-Bao's work.
