### PhD thesis

**Title**Algorithms and Data Structures in Computational Topology

**Authors**

*ClĂ©ment Maria*

**PhD thesis**from the University of Nice and INRIA Sophia Antipolis, France

**Abstract**The theory of homology generalizes the notion of connectivity in graphs to higher dimensions. It defines a family of groups on a domain, described discretely by a simplicial complex that captures the connected components, the holes, the cavities and higher-dimensional equivalents. In practice, the generality and flexibility of homology allows the analysis of complex data, interpreted as point clouds in metric spaces. The theory of persistent homology introduces a robust notion of homology for topology inference. Its applications are various and range from the description of high dimensional configuration spaces of complex dynamical systems, classification of shapes under deformations and learning in medical imaging. In this thesis, we explore the algorithmic ramifications of persistent homology. We first introduce the simplex tree, an efficient data structure to construct and maintain high dimensional simplicial complexes. We then present a fast implementation of persistent cohomology via the compressed annotation matrix data structure. We also refine the computation of persistence by describing ideas of homological torsion in this framework, and introduce the modular reconstruction method for computation. Finally, we present an algorithm to compute zigzag persistent homology, an algebraic generalization of persistence. To do so, we introduce new local transformation theorems in quiver representation theory, called diamond principles. All algorithms are implemented in the computational library Gudhi.

**Cite**BibTex from HAL

**HAL Id:**tel-01123744

**PhD Defense**slides