Cofiltrations of spanning trees in multiparameter persistent homology
Fritz Grimpen, Anastasios Stefanou
TL;DR
The paper tackles the problem of generating multiparameter persistent homology features with coefficients in a PID by leveraging spanning-tree concepts. It develops a framework where a cofiltration of order-minimal spanning trees yields an upper-set module epimorphic cover of the first cycle module $Z_1(X)$ and thus of $H_1(X)$ for a finite multifiltration $X$. Key contributions include the existence of such cofiltrations (Theorem main) and a higher-dimensional generalization to $n$-spanning complexes, establishing a path toward generating higher-dimensional invariants. The approach combines algebraic topology, order-theoretic constructions, and persistence-module theory to provide concrete generators and a structural decomposition that can aid computations in multiparameter settings with arbitrary PID coefficients.
Abstract
Given a multiparameter filtration of simplicial complexes, we consider the problem of explicitly constructing generators for the multipersistent homology groups with arbitrary PID coefficients. We propose the use of spanning trees as a tool to identify such generators by introducing a condition for persistent spanning trees, which is accompanied by an existence result for cofiltrations consisting of spanning trees. We also introduce a generalization of spanning trees, called spanning complexes, for dimensions higher than one, and we establish their existence as a first step towards this direction.
