نتایج جستجو برای: betti numbers

تعداد نتایج: 197228  

Journal: :Discrete Applied Mathematics 2009
Alexandre Dupas Guillaume Damiand

This paper presents a region merging process controlled by topological features on regions in 3D images. Betti numbers, a well-known topological invariant, are used as criteria. Classical and incremental algorithms to compute Betti numbers using information represented by the topological map of an image are provided. The region merging algorithm, which merges of any number of connected componen...

Journal: :Trans. Computational Science 2011
Rien van de Weygaert Gert Vegter Herbert Edelsbrunner Bernard J. T. Jones Pratyush Pranav Changbom Park Wojciech A. Hellwing Bob Eldering Nico Kruithof E. G. P. Bos Johan Hidding Job Feldbrugge Eline ten Have Matti van Engelen Manuel Caroli Monique Teillaud

We study the topology of the Megaparsec Cosmic Web in terms of the scale-dependent Betti numbers, which formalize the topological information content of the cosmic mass distribution. While the Betti numbers do not fully quantify topology, they extend the information beyond conventional cosmological studies of topology in terms of genus and Euler characteristic. The richer information content of...

1995
John Lott Wolfgang Lück

We give results on the L2-Betti numbers and Novikov-Shubin invariants of compact manifolds, especially 3-manifolds. We first study the Betti numbers and Novikov-Shubin invariants of a chain complex of Hilbert modules over a finite von Neumann algebra. We establish inequalities among the Novikov-Shubin invariants of the terms in a short exact sequence of chain complexes. Our algebraic results, a...

2009
CHRISTOPHER A. FRANCISCO ADAM VAN TUYL

We provide some new conditions under which the graded Betti numbers of a monomial ideal can be computed in terms of the graded Betti numbers of smaller ideals, thus complementing Eliahou and Kervaire’s splitting approach. As applications, we show that edge ideals of graphs are splittable, and we provide an iterative method for computing the Betti numbers of the cover ideals of Cohen-Macaulay bi...

Journal: :Int. J. Comput. Geometry Appl. 2015
Niccolò Cavazza Massimo Ferri Claudia Landi

An exact computation of the persistent Betti numbers of a submanifold X of a Euclidean space is possible only in a theoretical setting. In practical situations, only a finite sample of X is available. We show that, under suitable density conditions, it is possible to estimate the multidimensional persistent Betti numbers of X from the ones of a union of balls centered on the sample points; this...

2009
EDWARD L. GREEN DAN ZACHARIA

Let R be a connected selfinjective Artin algebra, and M an indecomposable nonprojective R-module with bounded Betti numbers lying in a regular component of the Auslander-Reiten quiver of R. We prove that the Auslander-Reiten sequence ending at M has at most two indecomposable summands in the middle term. Furthermore we show that the component of the Auslander-Reiten quiver containing M is eithe...

2008
CHRISTOPHER A. FRANCISCO TÀI HÀ ADAM VAN TUYL

We provide some new conditions under which the graded Betti numbers of a mono-mial ideal can be computed in terms of the graded Betti numbers of smaller ideals, thus complementing Eliahou and Kervaire's splitting approach. As applications, we show that edge ideals of graphs are splittable, and we provide an iterative method for computing the Betti numbers of the cover ideals of Cohen-Macaulay b...

2007
Saugata Basu

A classic result in real algebraic geometry due to Oleinik-Petrovsky, Thom and Milnor, bounds the topological complexity (the sum of the Betti numbers) of basic semi-algebraic sets. This bound is tight as one can construct examples having that many connected components. However, till now no signiicantly better bounds were known on the individual higher Betti numbers. In this paper we prove sepa...

2009
MICHAEL GOFF

Upper bounds on the topological Betti numbers of Vietoris-Rips complexes are established, and examples of such complexes with high Betti

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