Math 341

Topics in Geometry, Fall 2023

Current week   |   Moodle   |   Course information
Instructor: David Perkinson (schedule)
Text: Manifolds, notes by David Perkinson and Livia Xu based on the text Vector Analysis, by Klaus Jänich. These will be continually updated (last update: 11/17/23).
Office hours: Wed: 2-3, Thu: 1:30-3:00, Fri: 11-12, by appointment.
Midterm (Overleaf template for solutions).
Week 1: August 28 - September 1
Monday
Reading: Section 1: Introduction and Overview.

Wednesday Differential vector calculus (slides).
Reading: Appendix A. Vector Calculus in Euclidean Spaces.

Friday Topology (slides).
Reading: Appendix B. Topology. Reading questions.
Some breaking news.
Turn in: HW 1 (Overleaf solution template).

Video of the week   What is a manifold?

Week 2: September 4 - 8
Monday
No class: Labor Day.

Wednesday Definition of a manifold (slides).
Reading: Sections 1 and 2: Introduction, and Definition of a Manifold
Model for the projective plane (crosscap)

Friday Differentiable Maps.
Reading: Section 3: Differentiable Maps (slides).
Turn in: HW 2 (Overleaf solution template).

Video of the week   A Möbius strip hidden in the projective plane.

Week 3: September 11 - 15
Monday Tangent space (slides).
Reading: Sections 4.1, 4.2, and 4.3. (Three versions of tangent space, their equivalence and standard bases w.r.t. a chart.) Reading questions.
Wednesday Tangent space (slides).
Quiz topics.
Reading: Sections 4.1, 4.2, and 4.3.

Friday The tangent mapping (differential) (slides).
Reading: Section 4.4, The differential of a mapping of manifolds.
Turn in: HW3 (Overleaf solution template).

Video of the week   What is a moduli space?

Week 4: September 18 - 22
Monday Tensors (slides).
Reading: Linear algebra sections 5.1–3.1.
Wednesday Tensors and duality (slides).
Quiz topics.
Reading: Section 5.4.

Friday Tensors and duality. (See Wednesday's slides.)
Reading: Review linear algebra (Section 5).
Turn in: HW4 (Overleaf solution template).

Video of the week   What is the tensor product, anyway?

Week 5: September 25 - 29
Monday Vector bundles (slides).
Reading: Section 6.
Wednesday Tangent bundles (slides).
Quiz topics.
Reading: Section 7.

Friday Differential forms (slides).
Reading: Section 8.
Turn in: HW 5 (Overleaf solution template).

Week 6: October 2 - 6
Monday Exterior derivatives; orientations (slides).
Reading: Sections 8.2 and 9.
Wednesday Exterior derivatives; orientations (slides).
Quiz topics.
Reading: Sections 8.2 and 9.

Friday Integration of forms (slides).
Reading: Appendix C (Measure theory); Section 10.1..
Midterm exam distributed. The midterm covers the first four weeks of class. Thus, tensors on a vector space will be covered, but not vector bundles.
Here is the midterm (Overleaf solution template).
Turn in: HW 6 (Overleaf solution template).

Week 7: October 9 - 13
Monday Integration (slides).

Wednesday No class. No quiz.

Friday Manifolds with boundary. No class. Click on the title for today to access the lecture video (or go to our Moodle page).
Reading: Section 10.2.
Midterm due by 1:10 pm.

Week 8: October 23 - 27
Monday Stokes' theorem (slides).
Reading: Section 10.3.

Wednesday Stokes' theorem (continued from Monday).
Quiz topics.
Reading: Section 10.3.

Friday de Rham cohomology (slides).
Reading: Section 11.1.
Turn in: HW 7 (Overleaf solution template).

Week 9: October 30 - November 3
Monday Homotopy invariance of de Rham cohomology (slides).
Reading: Section 11.2.

Wednesday Homotopy invariance of de Rham cohomology; exact sequences (slides).
Quiz topics.
Reading: Section 11.2.

Friday Exact sequences (slides).
Reading: Appendix D (read D.1(exact sequences) carefully; at least skim D.2 (simplicial homology)).
Turn in: HW 8 (Overleaf solution template).

Week 10: November 6 - 10
Monday Mayer-Vietoris (slides).
Reading: Section 11.3.

Wednesday More topics in de Rham cohomology. (slides).
Quiz topics.
Reading: Section 11.

Friday Toric varieties: Introduction (slides).
Reading: Section 13.1.
Turn in: HW 9 (Overleaf solution template).

Week 11: November 13 - 17
Monday Toric varieties: Introduction. (slides, same as last Friday's).
Reading: Section 13.1.

Wednesday Toric varieties: polytopes, cohomology (slides).
Quiz topics.
Reading: Section 13.3.

Friday Toric varieties: cohomology; Hirzebruch surfaces (slides).
Reading: Section 13.3.
Turn in: HW 10 (Overleaf solution template).

Week 12: November 20 - 24
Monday Grassmannians (slides).
Reading: Section 14.1.

Wednesday Plücker embedding (slides).
Quiz: none this week.
Reading: Section 14.2.
Turn in: HW 11 (Overleaf solution template).

Friday Thanksgiving break.
Reading: None.

Week 13: November 27 - December 1
Monday Schubert varieties (slides).
Reading: Section 14.3.1 and 14.3 and Biography of Hermann Schubert.

Wednesday Schubert calculus.
Quiz: none this week.
Reading: Section 14.3. Also see problem 15 in Hilbert's problems, and the introduction to Grassmannians, flag varieties, and Gelfand–Zetlin polytopes.

Friday Schubert calculus (slides).
Reading: Section 14.3.
Turn in: HW 12 (Overleaf solution template).

Video of the week   Hilbert's 15th Problem: Schubert Calculus.

Week 14: December 4 - 8
Monday Schubert calculus.
Reading: Section 14.3.
Group problems (solutions).

Wednesday Four lines. (slides).
Quiz: none this week.
Reading: Section 14.3.

Friday No class.


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