Abstract categorical residues and Calabi-Yau structures

Inspired by the simple fact that a compact n-dimensional manifold-with-boundary which satisfies Poincaré-Lefschetz duality of dimension n has a boundary which itself satisfies Poincaré duality of dimension n, we show that the categorical formal punctured neighborhood of infinity, a canonical categorical construction associated to every $A_{\mathrm{\infty }}$ category, has a weak proper Calabi-Yau structure of dimension n-1 whenever the original $A_{\mathrm{\infty }}$ category admits a weak smooth Calabi-Yau structure of dimension n. Applications include proper Calabi-Yau structures on Rabinowitz Fukaya category of a Liouville manifold and Orlov’s singularity category of a proper singular Gorenstein scheme of finite type.