Birational Invariance in Punctured Log Gromov-Witten Theory
Samuel Johnston
TL;DR
This work extends birational invariance results from classical log Gromov–Witten theory to punctured log Gromov–Witten theory under log étale modifications. It introduces a universal modification stack \\mathfrak{M}_{\\gamma ightarrow au} and establishes cartesian diagrams and étaleness properties that align obstruction theories and virtual classes across targets X and \\tilde{X}, enabling comparison of punctured invariants. The paper further shows the invariance of canonical wall structures and intrinsic mirror algebras under such modifications, strengthening the connection between punctured GW theory and mirror symmetry. Decorated tropical types are developed to control ambiguities in lifts, boundedness results are obtained without global generation assumptions, and the results yield robust birational invariance for both canonical walls and mirror constructions in Gross–Siebert and intrinsic mirror frameworks.
Abstract
Given a log smooth scheme $(X,D)$, and a log étale modification $(\tilde{X},\tilde{D}) \rightarrow (X,D)$, we relate the punctured Gromov-Witten theory of $(\tilde{X},\tilde{D})$ to the punctured Gromov-Witten theory of $(X,D)$, generalizing results of Abramovich and Wise in the non-punctured setting in "Birational invariance in log Gromov-Witten Theory". Using the main comparison results, we show a form of log étale invariance for the logarithmic mirror algebras and canonical scattering diagrams constructed in "Intrinsic Mirror Symmetry" and "The Canonical Wall Structure and Intrinsic Mirror Symmetry" respectively.
