Math 529: Lecture Notes and Videos on Computational Topology

Copyright: I (Bala Krishnamoorthy) hold the copyright for all lecture scribes/notes, documents, and other materials including videos posted on these course web pages. These materials might not be used for commercial purposes without my consent.

Scribes from all lectures so far (as single big file)

Lec Date Topic(s) Scribe Video
1 Jan 13 syllabus, connected spaces, applications: patient trajectories, interface features in chemistry, discrete connectivity Scb1 Vid1
2 Jan 15 topology, open sets, interior, closure, and boundary; functions, homeomorphism, open disc \(\approx \mathbb{R}^2\), circle \(\not\approx\) annulus Scb2 Vid2
3 Jan 20 \(\mathbb{S}^2 \approx \mathbb{R}^2 \cup \{\infty\}\), stereographic projection, 2-manifold (with boundary), non/orientable manifolds, 0-, 1-manifolds Scb3 Vid3
4 Jan 22 finite subcover, compact, Hausdorff, completely separable, \(d\)-manifold, embedding, \(\mathbb{T}^2, \mathbb{R}P^2, \mathbb{K}^2\), connected sum Scb4 Vid4
5 Jan 27 classification of 2-manifolds, \(\mathbb{R}P^2 \, \# \, \mathbb{R}P^2 \approx \mathbb{K}^2\), simplex, face, simplicial complex, dimension, underlying space Scb5 Vid5
6 Jan 29 abstract simplicial complex (ASC), geometric realization of \(d\)-complex in \(\mathbb{R}^{2d+1}\), triangulation, ASCs of surfaces Scb6 Vid6
7 Feb  3 topological invariant, Euler characteristic, \(\chi(\mathbb{M}_1 \# \mathbb{M}_2)\)\(=\)\(\chi(\mathbb{M}_1)+\chi(\mathbb{M}_2)-2\), \(\chi+\)orientability: complete invariant Scb7 Vid7
8 Feb  5 genus, cross cap, using \(\chi(g\mathbb{R}P^2)\)\(=\)\(2-g\), orientation of a simplex, comparing orientations, orientable manifold Scb8 Vid8
9 Feb 10 propagating orientation, (barycentric) subdivision, star St\(\,v\), closed star Cl St\(\,v\), link Lk\(\,v\) of vertex \(v\), St\(\,\sigma\) of \(\sigma\)\(\in\)\(K\) Scb9 Vid9
10 Feb 12 St \(X\) of \(X \subset K\), Lk\(\,X\) example, poset representation of \(K\), principal simplices, homotopy, deformation retraction Scb10 Vid10
11 Feb 17 nerve (Nrv), Nrv is ASC, nerve theorem, Čech and Vietoris-Rips (VR) complexes, VR Lemma: \({\rm VR}(r)\)\(\subseteq\)\({\rm Čech}(\sqrt{2}r)\) Scb11 Vid11
12 Feb 19 proof of VR lemma, Voronoi diagram, Delaunay complex, general position, delaunay+voronoi in Matlab, filtration Scb12 Vid12
13 Feb 24 alpha complex, \(\rm{Alpha}(r) \subseteq \rm{Del}, \rm{Čech}(r)\), weighted alpha complex, empty sphere property, weak/strong witness Scb13 Vid13
14 Feb 26 strict witness complex, \(W_{\infty}(L,S) \subseteq \mbox{Del}_L\), lazy witness complex, groups, subgroups, cosets, homomorphisms Scb14 Vid14


Last modified: Thu Feb 26 16:10:18 PST 2026