The closed state space of affine Landau-Ginzburg B-models
Ed Segal
TL;DR
The paper develops a rigorous bridge between the Hochschild-type invariants of the category of B-branes in affine Landau-Ginzburg models and the geometric closed state-space given by differential forms with the $dW$-twisted differential. It constructs an explicit chain map and proves a quasi-isomorphism at the level of Borel-Moore Hochschild complexes, enabling a concrete realization of the closed sector from the open sector. The Kapustin-Li disc-correlator formula is recovered as the leading term of this chain map, linking worldsheet correlators to residues. The results extend to orbifolds via twisted group algebras and fixed-locus state spaces, providing a coherent framework for open-closed TCFTs in affine LG settings with and without singularities.
Abstract
We study the category of perfect cdg-modules over a curved algebra, and in particular the category of B-branes in an affine Landau-Ginzburg model. We construct an explicit chain map from the Hochschild complex of the category to the closed state space of the model, and prove that this is a quasi-isomorphism from the Borel-Moore Hochschild complex. Using the lowest-order term of our map we derive Kapustin and Li's formula for the correlator of an open-string state over a disc.
