Discrete Morse theory for computing cellular sheaf cohomology

Sheaves and sheaf cohomology are powerful tools in computational topology, greatly generalizing persistent homology. We develop an algorithm for simplifying the computation of cellular sheaf cohomology via (discrete) Morse-theoretic techniques. As a consequence, we derive efficient techniques for distributed computation of (ordinary) cohomology of a cell complex.Comment: 19 pages, 1 Figure. Added Section 5.

Parametrized Homology via Zigzag Persistence

This paper develops the idea of homology for 1-parameter families of topological spaces. We express parametrized homology as a collection of real intervals with each corresponding to a homological feature supported over that interval or, equivalently, as a persistence diagram. By defining persistence in terms of finite rectangle measures, we classify barcode intervals into four classes. Each of these conveys how the homological features perish at both ends of the interval over which they are defined

Duality and spherical adjunction from microlocalization -- An approach by contact isotopies

For a subanalytic Legendrian $\Lambda \subset S^{*}M$, we prove that when $\Lambda$ is either swappable or a full Legendrian stop, the microlocalization at infinity $m_\Lambda: \operatorname{Sh}_\Lambda(M) \rightarrow \operatorname{\mu sh}_\Lambda(\Lambda)$ is a spherical functor, and the spherical cotwist is the Serre functor on the subcategory $\operatorname{Sh}_\Lambda^b(M)_0$ of compactly supported sheaves with perfect stalks. In this case, when $M$ is compact the Verdier duality on $\operatorname{Sh}_\Lambda^b(M)$ extends naturally to all compact objects $\operatorname{Sh}_\Lambda^c(M)$. This is a sheaf theory counterpart (with weaker assumptions) of the results on the cap functor and cup functors between Fukaya categories. When proving spherical adjunction, we deduce the Sato-Saboff fiber sequence and construct the Guillermou doubling functor for any Reeb flow. As a setup for the Verdier duality statement, we study the dualizability of $\operatorname{Sh}_\Lambda(M)$ itself and obtain a classification result of colimit-preserving functors by convolutions of sheaf kernels.Comment: 74 pages, 5 figures. A new discussion around Proposition 4.1

Wrapped sheaves

We construct a sheaf-theoretic analogue of the wrapped Fukaya category in Lagrangian Floer theory, by localizing a category of sheaves microsupported away from some given $\Lambda \subset S^*M$ along continuation maps constructed using the Guillermou-Kashiwara-Schapira sheaf quantization. When $\Lambda$ is a subanalytic singular isotropic, we also construct a comparison map to the category of compact objects in the category of unbounded sheaves microsupported in $\Lambda$, and show that it is an equivalence. The last statement can be seen as a sheaf theoretical incarnation of the sheaf-Fukaya comparison theorem of Ganatra-Pardon-Shende.Comment: 54 pages, 4 figure