MAT 215A: (Graduate) Topology






Course information

Class Meetings

CRN 44986
Lectures: MWF 11:00-11:50 AM, Hunt 110
Discussion: T 10:00-10:50 AM, Wellman 107

[MAT 215A Course Syllabus]

Updated 9.20.25

[MAT 215A Class Calendar]

The class calendar is my personal lesson planning calendar. Lesson plans are subject to change.

Course instructor: Melissa Zhang

Course TA: Ian Sullivan

Instructor Office Hours: MSB 3240, M 4-5pm, F 2-3pm. See Canvas announcements for occasional modifications.

TA Office Hours: MSB 3240, W 4-5. See Canvas announcements for occasional modifications.

Textbook: Algebraic Topology by Allen Hatcher [Online Version]

Department syllabus for Mat215A: [link]


Homework

Homeworks are generally posted over the weekend and due Thursday nights at 9 pm.

[Take-Home Final Exam] [Final Exam Solutions]

Answers to some questions I was asked:

Question 3: You may assume that X is locally path-connected.

Question 3: "Universal covering space" in this problem means "simply-connected covering space".

Question 4: Should we assume that the CW complex X is finite-dimensional? Indeed the equation $\chi(\tilde X) = k \chi(X)$ only makes sense if $X$ is a finite CW complex, but for the rest of the problem you should not a priori assume that $X$ is finite-dimensional.

Question 4(a): May we use Proposition A.2 in Hatcher? You are welcome to, but your solution need not be too pedantic; the intended solution does not refer to this proposition (though it perhaps implicitly uses it). For this exam, it is enough to describe the CW structure on the covering space, with a brief justification of why this CW complex indeed recovers the covering space.

[HW07]

[HW06]

[HW05]

Problem 1.3.12 has been removed from this problem set (11.3.25).
Problem 6 (1.3.14) will be graded for completion / effort.

[HW04]

[HW03]

[HW02]

[HW01]


Lectures and Materials

[Week 11 Notes]

[Week 10 Notes]

[Week 9 Notes]

[Week 8 Notes]

[Exam 2] [Exam 2 Solutions]

[Week 7 Notes]

[Week 6 Notes]

[Week 5 Notes]

[Exam 1] [Exam 1 Solutions]

[Week 4 Notes]

[Week 3 Notes]

[Week 2 Notes]

[Commutative Diagrams]

Now with a section on lifts and extensions.

[Week 1 Notes]