Frosini, Patrizio ; Landi, Claudia
(2010)
*Uniqueness of models in persistent homology: the case of curves.*
[Preprint]

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## Abstract

We consider generic curves in R^2, i.e. generic C^1 functions f:S^1->R^2. We analyze these curves through the persistent homology groups of a filtration induced on S^1 by f. In particular, we consider the question whether these persistent homology groups uniquely characterize f, at least up to re-parameterizations of S^1. We give a partially positive answer to this question. More precisely, we prove that f=goh, where h:S^1->S^1$ is a C^1-diffeomorphism, if and only if the persistent homology groups of sof and sog coincide, for every s belonging to the group Sigma_2 generated by reflections in the coordinate axes. Moreover, for a smaller set of generic functions, we show that f and g are close to each other in the max-norm (up to re-parameterizations) if and only if, for every s in Sigma_2, the persistent Betti numbers functions of sof and sog are close to each other, with respect to a suitable distance.

Abstract

We consider generic curves in R^2, i.e. generic C^1 functions f:S^1->R^2. We analyze these curves through the persistent homology groups of a filtration induced on S^1 by f. In particular, we consider the question whether these persistent homology groups uniquely characterize f, at least up to re-parameterizations of S^1. We give a partially positive answer to this question. More precisely, we prove that f=goh, where h:S^1->S^1$ is a C^1-diffeomorphism, if and only if the persistent homology groups of sof and sog coincide, for every s belonging to the group Sigma_2 generated by reflections in the coordinate axes. Moreover, for a smaller set of generic functions, we show that f and g are close to each other in the max-norm (up to re-parameterizations) if and only if, for every s in Sigma_2, the persistent Betti numbers functions of sof and sog are close to each other, with respect to a suitable distance.

Document type

Preprint

Creators

Keywords

Persistent Betti numbers, reflections, matching distance

Subjects

DOI

Deposit date

29 Dec 2010 09:20

Last modified

16 May 2011 12:16

URI

## Other metadata

Document type

Preprint

Creators

Keywords

Persistent Betti numbers, reflections, matching distance

Subjects

DOI

Deposit date

29 Dec 2010 09:20

Last modified

16 May 2011 12:16

URI

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