Reflexivity and Hochschild Cohomology

Abstract

We characterise reflexive DG-categories, as introduced by Kuznetsov and Shinder, as the reflexive objects in the closed symmetric monoidal category of DG-categories localised at Morita equivalences. As consequences, we show that the Hochschild cohomology and the derived Picard group of a reflexive DG-category coincide with those of its derived category of cohomologically finite modules.