On the Hochschild cohomology of Tamarkin categories
Christopher Kuo, Vivek Shende, Bingyu Zhang
TL;DR
The paper develops a filtered Hochschild-theoretic framework for Tamarkin categories associated to open subsets of cotangent bundles, proving that the action-filtered Hochschild cohomology of the Tamarkin category 𝒯(U) matches the corresponding filtered symplectic cohomology SH of the neighborhood. It introduces a projector calculus for traces in the Tamarkin setting, expressing traces via integral kernels and wrapping constructs, and relates these to the Guillermou–Viterbo comparison to Floer theory. A Calabi–Yau structure is established for 𝒯(U), tying Hochschild (co)homology to trace data, and the action-window formalism provides a precise link between 𝒯(U) and SH with filtration. The results extend to generating function homology and clarify how capacities defined via SH are recovered in the Tamarkin/sheaf-theoretic framework, offering a robust bridge between microlocal sheaf theory and filtered Floer theory. Overall, the work furnishes a variational, sheaf-theoretic route to filtered symplectic invariants and their algebraic structures, reinforcing connections across Tamarkin, wrapped Fukaya categories, and generating function approaches.
Abstract
To any open subset of a cotangent bundle, Tamarkin has associated a certain quotient of a category of sheaves. Here we show that the Hochschild cohomology of this category agrees with filtered symplectic cohomology.
