Algebraic Topology notes
Reading Guide
This note collects the algebraic-topology background that later appears in characteristic classes and gauge examples: homotopy, fundamental groups, covering spaces, homology, cohomology, and the idea that global obstructions can be measured algebraically.
It is meant to explain why topology can produce integer-valued invariants, not to replace a full algebraic-topology text.
Shorter entry points now live beside this comprehensive version:
- Homotopy and Covering Spaces
- Homology, Cohomology, and Characteristic Classes