Henry Adams

Math 472: Introduction to Topology

                        

Colorado State University, Fall 2022

Instructor: Henry Adams
Email: henry dot adams at colostate dot edu
Office: Weber 120
Office Hours: Mondays at 3pm in Clark C362, or by appointment.

Lectures: MWF 2:00-2:50pm in Clark C363
Textbook: Basic Topology by M. A. Armstrong. This book is freely available as a PDF to CSU students if you login on the CSU library webpage.

Overview: This course is an introduction to topology. Topics covered include Euler's theorem, topologies on sets, continuous functions, homeomorphisms, sequences and convergence, metric spaces, compactness, connectedness, surfaces, manifolds, identification spaces, homotopy equivalences, the fundamental group, homotopy groups, Borsuk-Ulam theorem, Brouwer's fixed-point theorem, Morse theory, homology.

Goals: Students will become fluent with the main ideas and the language of topology, and will be able to communicate these ideas to others.

Syllabus: Here is the course syllabus.

Videos

The following videos are from Fall 2022.


What is an i-dimensional hole in a space?

Notes

Scans of Henry's lecture notes from 2016.

Schedule

Date Class Topic Remark

Aug 22 Introduction and course overview
Aug 24 What is an i-dimensional hole in a space? [Video]
Aug 26 A spontaneous introduction to knot theory

Aug 29 Recap of metric spaces
Aug 31 Open sets in metric spaces
Sept 2 Topological spaces

Sept 5 Holiday - no class!
Sept 7 Topological spaces; Stereographic projection Last day to drop or change grading option
Sept 9 Continuous functions; Spontaneous introduction to category theory

Sept 12 Continuous functions
Sept 14 Closed sets
Sept 16 The closure, interior, and boundary of a set Spontaneous discussion on applying to graduate school

Sept 19 Homeomorphisms
Sept 21 Homeomorphisms
Sept 23 Alex Elchesen: Category theory

Sept 26 Michael Moy: Compact spaces
Sept 28 Michael Moy: Compact spaces
Sept 30 Alex Elchesen: Category theory; Functors

Oct 3 Homework A, especially the boundary of a set
Oct 5 Connected spaces
Oct 7 Path-connected spaces

Oct 10 Fundamental group
Oct 12 Homotopic maps
Oct 14 Homotopic maps

Oct 17 Homotopy classes of maps form an equivalence relation
Oct 19 Fundamental group
Oct 21 Fundamental group

Oct 24 Michael Moy: Fundamental group: Functoriality, Brouwer's fixed point theorem
Oct 26 Fundamental group: Examples
Oct 28 Fundamental group: Examples

Oct 31 Free groups
Nov 2 Group presentations Dinner at Henry's at 5pm!
Nov 4 Fundamental group and the Projective plane Video of genus-2 torus

Nov 7 Homotopy groups
Nov 9 Evasion Paths in Mobile Sensor Networks
Nov 11 Homotopy equivalences between spaces

Nov 14 Homotopy equivalences between spaces
Nov 16 An introduction to applied topology
Nov 18 An introduction to applied topology

Fall Recess, Nov 21-25
Nov 28 Homology
Nov 30 Homology
Dec 2 Alex Elchesen: Morse theory, Manifolds

Dec 5 Homology
Dec 7 Brouwer's fixed point theorem, Invariance of domain

Math department poster session, Thursday, December 8, 9-11am, LSC Main Ballroom
Dec 9 Student project

Homework

Homework A (LaTeX Source) is due Wednesday, October 5.
Homework B (LaTeX Source) is due Wednesday, November 2.
Homework C (LaTeX Source) is due Wednesday, December 7.
Here are the Poster Session Guidelines.