arXiv subjects

Jesus F. Espinoza

Publications and source records attributed to Jesus F. Espinoza.

4 recordsLinked to original sources

arXiv2022

Collapsibility and homological properties of $\mathfrak{I}$-contractible transformations

The family of $\mathfrak{I}$-contractible graphs and contractible transformations was defined by A. Ivashchenko in the mid-90's. In this paper we study the collapsibility and homological properties of the clique complex associated to $\mathfrak{I}$-contractible graphs. We show that for any graph in a special subfamily of the $\mathfrak{I}$-contractible graphs (the strong $\mathfrak{I}$-contractible ones) its clique complex is collapsible. Moreover, we present an algorithm that allows us to verify if any graph is strong $\mathfrak{I}$-contractible, as well as an algorithm to delete those vertices whose open neighborhood is also strong $\mathfrak{I}$-contractible. Finally, we show how to use these algorithms to compute the persistent homology of an arbitrary Vietoris-Rips complex for applications in topological data analysis.

math.CO↗

arXiv2019

A numerical approach for the filtered generalized Cech complex

In this paper, we present an algorithm to compute the filtered generalized Čech complex for a finite collection of disks in the plane, which don't necessarily have the same radius. The key step behind the algorithm is to calculate the minimum scale factor needed to ensure rescaled disks have a nonempty intersection, through a numerical approach, whose convergence is guaranteed by a generalization of the well-known Vietoris-Rips Lemma, which we also prove in an alternative way, using elementary geometric arguments. We present two applications of our main results. We give an algorithm for computing the 2-dimensional filtered generalized Čech complex of a finite collection of $d$-dimensional disks in $\mathbb{R}^d$. In addition, we show how the algorithm yields the minimal enclosing ball for a finite set of points in the plane.

cs.CG↗

arXiv2019

On smooth families of exact forms

For a smooth family of exact forms on a smooth manifold, an algorithm for computing a primitive family smoothly dependent on parameters is given. The algorithm is presented in the context of a diagram chasing argument in the Čech-de Rham complex. In addition, explicit formulas for such primitive family are presented.

math.DG↗

arXiv2018

Global product structure for a space of special matrices

The importance of the Hurwitz Metzler matrices and the Hurwitz symmetric matrices can be appreciated in different applications: communication networks, biology and economics are some of them. In this paper, we use an approach of differential topology for studying such matrices. Our results are as follows: the space of the $n\times n$ Hurwitz symmetric matrices has a product manifold structure given by the space of the $(n-1) \times (n-1)$ Hurwitz symmetric matrices and the euclidean space. Additionally we study the space of Hurwitz Metzler matrices and these ideas let us do an analysis of robustness of Hurwitz Metzler matrices. In particular, we study the Insulin Model as application.

math.OC↗