Schedule for Math 642: Modern Algebra II, Winter 2026 (CRN 43986)

Week One (2026-1-5 and 2025-10-7)

This week, we will introduce tensor products over commutative rings.

Week Two (2026-1-12 and 2026-1-14)

This week, we will prove basic properties of tensor products.

Week Three (2026-1-21)

This week, we will reacquaint ourselves with some basics of category theory.
HW1 is due on 2026-1-21.
Here are solutions to HW1, written by Ernesto.

Week Four (2026-1-26 and 2026-1-28)

This week, we introduce Hom functors and projective modules.

Week Five (2026-2-2 and 2026-2-4)

More projective modules.

Week Six (2026-2-9 and 2026-2-11)

Injective modules.
HW2 is due on 2026-2-11.
Here are solutions to HW2, written by Ernesto.

Week Seven (2026-2-16 and 2026-2-18)

More injective modules.

Week Eight (2026-2-23 and 2026-2-25)

Limits.

Week Nine (2026-3-2 and 2026-3-4)

More limits.
HW3 is due on 2026-3-4.

Week Ten (2026-3-9 and 2026-3-11)

Homology.
HW4 is due on 2026-3-18.

Finals Week

The Final Exam is scheduled for Wednesday 2026-3-18, at 3:40pm–5:30pm, in our regular classroom. Most likely, this is when the final HW will be due.