Computing Flat-Injective Presentations of Multiparameter Persistence Modules

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Lenzen, Fabian
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915613694230528
author Lenzen, Fabian
author_facet Lenzen, Fabian
contents A flat-injective presentation of a multiparameter persistence module $M$ characterizes $M$ as the image of a morphism from a flat to an injective persistence module. Like flat or injective presentations, flat-injective presentations can be easily represented by a single graded matrix, completely describe the persistence module up to isomorphism, and can be used as starting point to compute other invariants of it,such as the rank invariant, persistence images, and others. If all homology modules of a bounded chain complex $F_\bullet$ of flat $n$-parameter modules are finite dimensional,it is known that $F_\bullet$ and its shifted image $νF_\bullet[n]$ under the Nakayama functor are quasi-isomorphic, where $νF_\bullet[n]$ is a complex of injective modules. We give an explicit construction of a quasi-isomorphism $ϕ_\bullet\colon F_\bullet \to νF_\bullet[n]$,based on the boundary morphisms of $F_\bullet$. If $F_\bullet$ is a flat resolution of a finite dimensional persistence module $M$,then the degree-zero part $ϕ_0\colon F_0 \to νF_n$ is a flat-injective resolution of $M$. From our construction of $ϕ$, we obtain a method to compute a matrix representing $ϕ_0$from the matrices representing the resolution $F_\bullet$. A Julia package implementing this method is available.
format Preprint
id arxiv_https___arxiv_org_abs_2401_06008
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Computing Flat-Injective Presentations of Multiparameter Persistence Modules
Lenzen, Fabian
Commutative Algebra
Algebraic Topology
13P20, 55N31, 13D02 (Primary) 68T09, 13-04, 62R40 (Secondary)
A flat-injective presentation of a multiparameter persistence module $M$ characterizes $M$ as the image of a morphism from a flat to an injective persistence module. Like flat or injective presentations, flat-injective presentations can be easily represented by a single graded matrix, completely describe the persistence module up to isomorphism, and can be used as starting point to compute other invariants of it,such as the rank invariant, persistence images, and others. If all homology modules of a bounded chain complex $F_\bullet$ of flat $n$-parameter modules are finite dimensional,it is known that $F_\bullet$ and its shifted image $νF_\bullet[n]$ under the Nakayama functor are quasi-isomorphic, where $νF_\bullet[n]$ is a complex of injective modules. We give an explicit construction of a quasi-isomorphism $ϕ_\bullet\colon F_\bullet \to νF_\bullet[n]$,based on the boundary morphisms of $F_\bullet$. If $F_\bullet$ is a flat resolution of a finite dimensional persistence module $M$,then the degree-zero part $ϕ_0\colon F_0 \to νF_n$ is a flat-injective resolution of $M$. From our construction of $ϕ$, we obtain a method to compute a matrix representing $ϕ_0$from the matrices representing the resolution $F_\bullet$. A Julia package implementing this method is available.
title Computing Flat-Injective Presentations of Multiparameter Persistence Modules
topic Commutative Algebra
Algebraic Topology
13P20, 55N31, 13D02 (Primary) 68T09, 13-04, 62R40 (Secondary)
url https://arxiv.org/abs/2401.06008