This is an old course webpage

Math 225C: Algebraic Topology

Spring 2023

Instructor: Sucharit Sarkar.
Class: MWF 13:00-13:50, MS 5117.
Office hours: W 11:30-12:30, MS 6909.

TA: Jung Joo Suh.
TA discussion section: Th 13:00-13:50, MS 5127.
TA office hours: W 15:00-16:15, Th 15:30-17:00, MS 3949.

Textbook: Hatcher, Algebraic Topology, Chapters 1-3.
Syllabus: Basic concepts of homotopy theory, fundamental group, Van Kampen theorem, and covering spaces, singular homology and cohomology theory, axioms of homology theory, Mayer-Vietoris sequence, excision, cup products, calculation of homology and cohomology of standard spaces, cell complexes and cellular homology, Poincare duality.
Useful links: Department page, Gradescope, old Qualifying exams.

Prerequisites: Hatcher Chapter 0, basic knowledge of algebra (110, 115) and point set topology (121). Try these problems to check your preparedness.
For undergraduates: If you are an undergraduate trying to enroll in 225C, you will need a PTE from me. You need to meet the above prerequisites, and in addition, you need to be a Math major with strong grades (straight A's in all undergraduate Math courses with at most one B in a non-algebra non-topology undergraduate Math course). If you meet these requirements, send me an email requesting a PTE, and attach a copy of your transcript.

Homework: Homeworks are due on Fridays. You must upload your homeworks (either LaTeX-ed, or handwritten and then scanned) to Gradescope. Late homeworks will be graded/ungraded based on the TA's discretion. However, your lowest homework score will be dropped when computing your grade.
HW Due on Problems
1 2023-04-14 0: 1, 2, 3, 4, 9, 10, 11, 13, 1.1: 1, 2, 3, 5, 6.
2 2023-04-21 0: 14, 15, 16, 17, 19, 1.1: 8, 9, 16, 17, 20, 1.2: 3, 6, 7, 8, 22.
3 2023-04-28 1.3: 4, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 27, 30, 32.
4 2023-05-05 2.1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
5 2023-05-12 2.1: 11, 12, 13, 14, 15, 16, 18, 23, 24, 30.
6 2023-05-19 2.1: 17, 19, 20, 21, 22, 26, 27, 29, 31, 2.2: 27, 28, 29.
7 2023-05-26 2.2: 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 16.
8 2023-06-02 2.2: 14, 15, 17, 19, 20, 21, 22, 23, 32, 33, 41, 43.
9 2023-06-09 3.2: 1, 3, 7, 8, 11, 3.A: 1, 3, 3.B: 1, 2.
You should write down with whom you worked at the top of each assignment. You should also cite any sources (other than lectures and the textbook) that you use.

Exams: The final is take-home; you must upload your exam (either LaTeX-ed, or handwritten and then scanned) to Gradescope by 2023-06-14. There will be no make-up exams. Taking the final exam is mandatory. In particular, note that university policy requires that a student who misses the finals be automatically given F, unless it is due to extreme and documented circumstances, in which case, if the performance in the course is otherwise satisfactory, the grade might be I.

Grading: Numerical grades will be recorded in Gradescope. The composite numerical grade will be computed as 70% HW + 30% Final, and the final letter grades will be assigned based on that. If you believe a problem on a homework or an exam has been graded incorrectly, or that your score was not correctly recorded in the Gradescope, you must bring this to the attention of the instructor within 10 calendar days of the due date of the assignment in question, or the date of the exam, and before the end of the quarter. Grading complaints not initiated within this period of time will not be considered. Please verify in a timely manner that your scores are correctly recorded on Gradescope.