Filtrations induced by continuous functions
Abstract
In Persistent Homology and Topology, filtrations are usually given by introducing an ordered collection of sets or a continuous function from a topological space to $\R^n$. A natural question arises, whether these approaches are equivalent or not. In this paper we study this problem and prove that, while the answer to the previous question is negative in the general case, the approach by continuous functions is not restrictive with respect to the other, provided that some natural stability and completeness assumptions are made. In particular, we show that every compact and stable 1dimensional filtration of a compact metric space is induced by a continuous function. Moreover, we extend the previous result to the case of multidimensional filtrations, requiring that our filtration is also complete. Three examples show that we cannot drop the assumptions about stability and completeness. Consequences of our results on the definition of a distance between filtrations are finally discussed.
 Publication:

arXiv eprints
 Pub Date:
 April 2013
 arXiv:
 arXiv:1304.1268
 Bibcode:
 2013arXiv1304.1268D
 Keywords:

 Mathematics  General Topology;
 Computer Science  Computational Geometry;
 Primary 54E45;
 Secondary 65D18;
 68U05
 EPrint:
 13 pages, 4 figures