Delta Complexes, Betti Numbers, and Torsion in Algebraic Topology

Explore the advanced concepts of algebraic topology in this 48-minute lecture on delta complexes, Betti numbers, and torsion. Delve into the computation of homology groups for a torus using delta-complexes, a flexible approach to simplicial complexes. Learn how to calculate homology groups using just two triangles in a standard square planar representation of a torus with identified edges. Discover the phenomenon of torsion when computing the homology of a projective plane, where a homology group becomes a finite commutative group. Understand Betti numbers as ranks of homology groups and their relation to the Euler characteristic. Gain insights into subgroups of Z plus Z and the algebraic formalities of homology group computation. This lecture provides a comprehensive exploration of key topics in algebraic topology, offering a deep understanding of complex mathematical structures and their properties.

Delta complexes, Betti numbers and torsion | Algebraic Topology | NJ Wildberger