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ALGEBRAIC TOPOLOGY CLASS

Class is on Mondays 13:00-14:30 (NEW TIME!) on zoom and on Thursdays 11:30-13:00 ​on zoom​. Note that the links for Monday and Thursday classes are different (please check both rooms just in case)

All lecture notes and videos are available on ucloud and are also linked on this page. 

Office hours  are Tuesdays 11-12 on zoom can be scheduled via email​, where you can contact me if you have any questions or problems.

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CLASS OUTLINE

0. Introduction (CW complexes, homotopy)
1. Fundamental group and covering spaces
2. Homology
3. Cohomology 
4. Poincaré duality (?)

Class outline
Class schedule

Oct.1. (Thu) 11:30-13:00

1. Introduction, CW-complexes, homotopies

Oct.5. (Mon) 13:15-14:45

2. Homotopies (continued)

Oct.8. (Thu) 11:30-13:00

3. Fundamental group (definition, basic properties)

Oct.12. (Mon) 13:00-14:30

NEW TIME!

4. Fundamental group of the circle

Oct.15. (Thu) 11:35-13:00

5. Fundamental group (applications)

Oct.19. (Mon) 13:00-14:30

6. Van Kampen Theorem

Oct.22. (Thu) 11:30-13:00

7. Covering Spaces (definition, lifting criteria)

Oct.29. (Thu) 11:30-13:00

8. Covering Spaces (Galois-like connection, construction of covering spaces for a given subgroup)

Nov.5. (Thu) 11:30-13:00

9. Application of covering spaces in group theory, manifolds

Nov.9. (Mon) 13:00-14:30

10. Homology (simplices, definition, reduced homology)

Nov.12. (Thu) 11:30-13:00

11. Homology (relation to Fundamental group, homological algebra)

Nov.16. (Mon) 13:00-14:30

12. Chain homotopic maps, relative homology, long exact sequence of homologies

Nov.19. (Thu) 11:30-13:00

13. Excision, homology of the sphere

Nov.23. (Mon) 13:00-14:30

14. Applications of the homology of the sphere, Mayer Vietoris sequence

Nov.26. (Thu) 11:30-13:00

15. Proof of Mayer Vietoris sequence and Excision

Nov.30. (Mon) 13:00-14:30

16. Degree

Dec.3. (Thu) 11:30-13:00

17. Cellular Homology

Dec.7. (Mon) 13:00-14:30

18. Homology with coefficients, Categories and Functors

Dec.10. (Thu) 11:30-13:00

19. Generalised homology theories, Geometric interpretation of Homology 

Dec.14. (Mon) 13:00-14:30

20. Cohomology (initial definitions)

(coming soon)

Dec.17. (Thu) 11:35-13:00

21. Cohomology of a space, cross product

(coming soon)

(coming soon)

  • lecture notes

  • video

(coming soon)

  • lecture notes

  • video

(coming soon)

(coming soon)

  • lecture notes

  • video

(coming soon)

(coming soon)

  • lecture notes

  • video

(coming soon)

(coming soon)

  • lecture notes

  • video

CLASS SCHEDULE

(refreshed after each class)

Oct.1. (Thu) 11:30-13:00

1. Introduction, CW-complexes, homotopies

Oct.5. (Mon) 13:15-14:45

2. Homotopies (continued)

Oct.8. (Thu) 11:30-13:00

3. Fundamental group (definition, basic properties)

Oct.12. (Mon) 13:00-14:30

NEW TIME!

4. Fundamental group of the circle

Oct.15. (Thu) 11:35-13:00

5. Fundamental group (applications)

Oct.19. (Mon) 13:00-14:30

6. Van Kampen Theorem

Oct.22. (Thu) 11:30-13:00

7. Covering Spaces (definition, lifting criteria)

Oct.29. (Thu) 11:30-13:00

8. Covering Spaces (Galois-like connection, construction of covering spaces for a given subgroup)

Nov.5. (Thu) 11:30-13:00

9. Application of covering spaces in group theory, manifolds

Nov.9. (Mon) 13:00-14:30

10. Homology (simplices, definition, reduced homology)

Nov.12. (Thu) 11:30-13:00

11. Homology (relation to Fundamental group, homological algebra)

Nov.16. (Mon) 13:00-14:30

12. Chain homotopic maps, relative homology, long exact sequence of homologies

Nov.19. (Thu) 11:30-13:00

13. Excision, homology of the sphere

Nov.23. (Mon) 13:00-14:30

14. Applications of the homology of the sphere, Mayer Vietoris sequence

Nov.26. (Thu) 11:30-13:00

15. Proof of Mayer Vietoris sequence and Excision

Nov.30. (Mon) 13:00-14:30

16. Degree

Dec.3. (Thu) 11:30-13:00

17. Cellular Homology

Dec.7. (Mon) 13:00-14:30

18. Homology with coefficients, Categories and Functors

Dec.10. (Thu) 11:30-13:00

19. Generalised homology theories, Geometric interpretation of Homology 

Dec.14. (Mon) 13:00-14:30

20. Cohomology (initial definitions)

Dec.17. (Thu) 11:30-13:00

21. Cohomology of a space, cross product

Merry Xmas!

22. The cohomology ring (properties of cup product)

Jan.7. (Thu) 11:30-13:00

Jan.11. (Mon) 13:00-14:30

(coming soon)

  • lecture notes

  • video

Jan.14. (Thu) 11:30-13:00

(coming soon)

  • lecture notes

  • video

Jan.18. (Mon) 13:00-14:30

(coming soon)

  • lecture notes

  • video

Jan.21. (Thu) 11:30-13:00

(coming soon)

  • lecture notes

  • video

Jan.25. (Mon) 13:00-14:30

(coming soon)

  • lecture notes

  • video

Jan.28. (Thu) 11:30-13:00

(coming soon)

  • lecture notes

  • video

EXAM RULES

BEFORE THE EXAM

  • The topic of the exam is everything that has been discussed in the lectures. All materials are available on my this website and on ucloud (password is as usual);

  • There are some proofs, that are left as exercises. These proofs are modelled on proofs that we have discussed earlier. As a preparation, it is a good idea to think these through, maybe write them down;

  • Some other proofs are skipped, and I am not expecting you to know them for the exam;

  • We have basically followed the book of Allen Hatcher: Algebraic Topology that can be downloaded here;

  • There are of course small deviations from the book, wherever I found a different approach better for our purposes, but all of it is in the online lecture notes;

  • If you have questions, then please write me an email, and I can answer in writing, or we could schedule an online meeting;

  • I prefer early exams, it is better for both you and me. You should email me about 2 weeks before you are ready to take the exam, and we will schedule a time that works for both of us. (I will not be available on the first week of February, but you can take the exam during the last week of January as well).

DURING THE EXAM

  • This semester again the exam will be held on zoom individually. After we scheduled a time slot I will send you an invitation link just as for the class. Both of us will have our video and audio on, but, of course, there will be no recording. 

  • Before the exam starts you will have to show your photo id to verify your identity and you will need to agree to the format of the exam;

  • As a start, I will ask you about a wider topic (e.g. basic definition. and properties of the fundamental group, the fundamental group of the circle, covering spaces, Mayer Vietoris sequence, cup product in cohomology,...) and after a couple of minutes of thinking you should start to present the main definitions, theorems and lemmas in the given topic, I will ask questions on the way and specify if you should go into more details.

  • Once we have discussed the first topic I will ask narrower questions about some of the other topics (e.g. state and prove the Brower fixed point theorem, what is the main idea in the proof of Excision, how do you compute the homology of a sphere), these could include simple exercises, computations, generally easier than the one from the exercise session. You are not expected to be able to solve all the exercises without help, but you should be able to start working on them and finish them with my help. I expect that all of this will take about an hour. 

  • You are not allowed to use any help (oral, online or written, ...) during the exam, and I have to terminate the exam if I suspect that any illegal aids have been used.

  • In the exam, you might need to draw pictures or write formulas. You should prepare a way to do this. Here are some suggestions:

    • zoom has an integrated whiteboard, that you can use moderately well even with a mouse or a touchpad (if you need it, I could send you an invitation to an empty practice room before the exam);

    • you can use white paper with a thick and dark pen, and show it to the camera, or send it to me as a file through email;

    • if you have a blackboard or whiteboard at home you can direct your camera to it. 

       

       Please let me know what option you are planning to use ahead of time.

  • ​If the internet connection turns out to be insufficient for the exam we will communicate by email to figure out a good solution.

  • I know, that this is a hard and unusual situation for all of us. Let me know if you have complications, or if you need help, and we will make it work. 

  • Here is a link with useful tips from the University on how to prepare for the exam. Please read it before the exam.  

​

Stay safe, and as usual ask questions!

​

Oct.1. (Thu) 11:30-13:00

1. Introduction, CW-complexes, homotopies

Oct.5. (Mon) 13:15-14:45

2. Homotopies (continued)

Oct.8. (Thu) 11:30-13:00

3. Fundamental group (definition, basic properties)

Oct.12. (Mon) 13:00-14:30

NEW TIME!

4. Fundamental group of the circle

Oct.15. (Thu) 11:35-13:00

5. Fundamental group (applications)

Oct.19. (Mon) 13:00-14:30

6. Van Kampen Theorem

Oct.22. (Thu) 11:30-13:00

7. Covering Spaces (definition, lifting criteria)

Oct.29. (Thu) 11:30-13:00

8. Covering Spaces (Galois-like connection, construction of covering spaces for a given subgroup)

Nov.5. (Thu) 11:30-13:00

9. Application of covering spaces in group theory, manifolds

Nov.9. (Mon) 13:00-14:30

10. Homology (simplices, definition, reduced homology)

Nov.12. (Thu) 11:30-13:00

11. Homology (relation to Fundamental group, homological algebra)

Nov.16. (Mon) 13:00-14:30

12. Chain homotopic maps, relative homology, long exact sequence of homologies

Nov.19. (Thu) 11:30-13:00

13. Excision, homology of the sphere

Nov.23. (Mon) 13:00-14:30

14. Applications of the homology of the sphere, Mayer Vietoris sequence

Nov.26. (Thu) 11:30-13:00

15. Proof of Mayer Vietoris sequence and Excision

Nov.30. (Mon) 13:00-14:30

16. Degree

Dec.3. (Thu) 11:30-13:00

17. Cellular Homology

Dec.7. (Mon) 13:00-14:30

18. Homology with coefficients, Categories and Functors

Dec.10. (Thu) 11:30-13:00

19. Generalised homology theories, Geometric interpretation of Homology 

Dec.14. (Mon) 13:00-14:30

20. Cohomology (initial definitions)

Dec.17. (Thu) 11:30-13:00

21. Cohomology of a space, cross product

Merry Xmas!

Jan.7. (Thu) 11:30-13:00

22. The cohomology ring (properties of cup product)

Exam rules at the bottom of the page

Jan.11. (Mon) 13:00-14:30

 23. The cup product is skew symmetric, cohomology ring of product of spheres

Jan.14. (Thu) 11:30-13:00

24.Relative cup product, cohomology of projective spaces

Jan.18. (Mon) 13:00-14:30

25. Cap product, statement of Poincare duality

Jan.21. (Thu) 11:30-13:00

26. Applications of Poincare duality, local R-orientation

Jan.25. (Mon) 13:00-14:30

27. Sketch of proof for Poincare duality

Jan.28. (Thu) 11:30-13:00

(coming soon)

  • lecture notes

  • video

Exam
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