Math 524: Lecture Notes and Videos on Algebraic 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 a single big file)

Lec Date Topic(s) Scribe Video
1 Aug 19 syllabus, continuous functions, neighborhood of a point, topological space, homeomorphism, showing \(\mathbb{R}^1 \not\approx \mathbb{R}^2\) Scb1 Vid1
2 Aug 21 open sets, geometric independence (GI), \(n\)-simplex, barycentric coordinates, dimension, boundary, properties of simplices Scb2 Vid2
3 Aug 26 simplicial complex \(K\), subcomplex, \(p\)-skeleton \(K^{(p)}\), underlying space \(|K|\), two topologies for \(|K|\), properties of \(|K|\) Scb3 Vid3
4 Aug 28 star, closed star, link, properties, simplicial maps, abstract simplicial complex (ASC), vertex scheme, geometric realization Scb4 Vid4
5 Sep   2 ASC examples: cylinder, Möbius strip, torus, Klein bottle; algebra review: groups, homomorphism, finitely generated Scb5 Vid5
6 Sep   4 internal direct sum, results on finitely generated abelian groups, betti number, torsion coefficients, orientation of simplex Scb6 Vid6
7 Sep   9 \(p\)-chain, elementary \(p\)-chain, group of \(p\)-chains \(C_p(K)\), boundary homo'm, fundamental lemma of homology: \(\partial_p\partial_{p+1} = 0\) Scb7 Vid7
8 Sep 11 cycles, boundaries, homology group \(H_p(K) = Z_p(K)/B_p(K)\), pushing chain off an edge, chain carried by subcomplex Scb8 Vid8
9 Sep 16 homology groups of torus \((\mathbb{T}^2)\) and Klein bottle (\(\mathbb{K}^2\)): \(H_1(\mathbb{T}^2) \simeq \mathbb{Z}\oplus \mathbb{Z}, H_2(\mathbb{T}^2) \simeq \mathbb{Z}\); \(H_1(\mathbb{K}^2) \simeq \mathbb{Z}\oplus \mathbb{Z}_2\,, H_2(\mathbb{K}^2) = 0\) Scb9 Vid9


Last modified: Tue Sep 16 17:54:27 PDT 2025