Tracking the Persistence of Harmonic Chains: Barcode and Stability
Tao Hou, Salman Parsa, Bei Wang
TL;DR
The paper introduces the harmonic chain barcode, a stable, canonical topological descriptor that tracks the evolution of harmonic chains along filtrations, addressing non-uniqueness issues in ordinary persistence representations. It proves stability analogous to ordinary persistence and provides a cubic-time algorithm to compute the harmonic chain barcode on filtrations with $m$ simplices, enabling practical use in feature extraction and machine learning. By embedding the problem into a $\mathbb{U}$-indexed, block-decomposable framework and lifting to $\mathbb{R}^2$-indexed modules, it establishes a robust stability theory for sublevel-set filtrations and demonstrates a concrete interleaving-based bound on barcode perturbations. Overall, the harmonic chain barcode enriches persistent-homology descriptors with canonical representatives and stability guarantees, broadening potential applications in topology-driven data analysis and ML pipelines.
Abstract
The persistence barcode is a topological descriptor of data that plays a fundamental role in topological data analysis. Given a filtration of data, the persistence barcode tracks the evolution of its homology groups. In this paper, we introduce a new type of barcode, called the harmonic chain barcode, which tracks the evolution of harmonic chains. In addition, we show that the harmonic chain barcode is stable. Given a filtration of a simplicial complex of size $m$, we present an algorithm to compute its harmonic chain barcode in $O(m^3)$ time. Consequently, the harmonic chain barcode can enrich the family of topological descriptors in applications where a persistence barcode is applicable, such as feature vectorization and machine learning.
