Floer homology via Twisted Loop Spaces

Abstract

Answering a question of Witten, we introduce a novel method for defining an integral version of Lagrangian Floer homology, removing the standard restriction that the Lagrangians in question must be relatively Pin. Using this technique, we derive stronger bounds on the self-intersection of certain exact Lagrangians ${\mathbb{RP}}^2\times L^{\prime }$ than those that follow from traditional methods. We define a integral version of Lagrangian Floer homology all oriented closed exact Lagrangians $L$ in a Liouville domain and prove a general self-intersection bound coming from the algebraic properties of the diagonal bimodule of a twist of the dg-algebra of chains on the based loop space of $L$.

47 pages, 6 figures. typos corrected, slight figure placement change, acknowledgements added