Instructor(s): Asher Auel

Course on canvas.dartmouth.edu.
Course on math.dartmouth.edu.

Syllabus

Week Date Topics Reading Homework
1 Tue 16 Sep History of abstract algebra. Some set theory notations. The notion of a group. Examples of groups: modular arithmetic and symmetry groups. Multiplicative group modulo n. Dihedral groups. DF 0.1-0.3, 1.1-1.2
Thu 18 Sep Order of an element and of a group. Symmetric groups. Cycle decomposition. Fields. Matrix groups. DF 1.2-1.4
Fri 19 Sep X-TA Logic, set theory, functions. DF 0.1-0.3
2 Tue 23 Sep Generating set. Presentation. Homomorphisms and isomorphisms. Cyclic groups. DF 1.4-1.6 Problem Set #0
Thu 25 Sep Subgroups. Statement of Lagrange's Theorem. Kernel. Image. Group actions. Examples of group actions. DF 1.7, 2.1-2.2, 4.1-4.2
Fri 26 Sep X-TA Proof writing. Mathematical induction. DF 0.1-0.3
3 Tue 30 Sep Permutation representation. Cayley's Theorem. Orbits. Stabilizers. Conjugation action. Conjugacy classes. DF 4.1-4.3 Problem Set #1
Thu 02 Oct Yom Kippur
Fri 03 Oct X-TA Proof writing. Quiz review.
4 Tue 07 Oct Classification of cyclic groups, and their generators and subgroups. Quiz DF 2.3, 3.1-3.2 Quiz 1 Review

Problem Set #2
Thu 09 Oct Quotient groups via homomorphisms. Quotient groups via cosets. Normal subgroups. Natural projection. Normal subgroups are kernels. Lagrange's theorem. DF 3.1-3.2
Fri 10 Oct Make-up lecture. Homomorphisms from quotient groups. First isomorphism theorem. Third and fourth isomorphism theorems. Lattice of subgroups. DF 2.5, 3.3, 4.1
5 Tue 14 Oct Intersections and joins in the lattice of subgroups. Orbit-stabilizer theorem. Composition series. Jordan-Hölder theorem. Simple groups. Classification of finite simple groups. DF 2.4, 3.4 Problem Set #3
Thu 16 Oct Alternating group. Orbit-stabilizer theorem. Conjugacy classes. Cycle type and conjugacy classes in the symmetric group. DF 3.5, 4.1, 4.2, 4.3
Fri 17 Oct X-TA Midterm exam review.
6 Tue 21 Oct Class equation. A5 is a simple group. Sylow p-subgroup. Sylow's Theorem. DF 4.3, 4.4, 4.5 Midterm Review Sheet
Thu 23 Oct Applications of Sylow's Theorem. Proof of Sylow's Theorems. Groups of order up to 60. DF 4.5
Fri 24 Oct Midterm Exam
7 Tue 28 Oct Fundamental theorem of finitely generated abelian groups. Classification of finite abelian groups. Classification of finite abelian groups. Invariant factors. Elementary divisors. DF 5.1, 5.2 Problem Set #4
Thu 30 Oct Rings. Fields. Division rings. Quaternions. Matrix rings. Group rings. Zero-divisors. Units. Integral domains. DF 7.1-7.2
Fri 31 Oct X-TA More examples of rings.
8 Tue 04 Nov Polynomial rings. Ring homomorphisms. Ideals. Quotient rings. DF 7.1-7.3 Problem Set #5
Thu 06 Nov TA lecturing. Isomophism Theorems for Rings. Simple rings. Principal ideals. Principal ideal domains (PIDs). Z is a PID. Polynomial rings. F[x] is a PID. DF 7.3-7.4, 8.2, 9.1-9.2
Fri 07 Nov X-TA Quiz review.
9 Tue 11 Nov PIDs. Euclidean domains. Euclidean implies PID. Quadratic integer rings. Z[i] is Euclidean. When is a quadratic integer ring Euclidean or a PID? Irreducible and prime elements. Quiz. DF 7.1, 8.1-8.3, 9.1-9.2 Quiz 2 review

Problem Set #6
Thu 13 Nov Unique factorization domains (UFDs). Noetherian rings. Principal ideal domains are unique factorization domains. The fundamental theorem of arithmetic. DF 8.2-8.3, 9.3
Fri 10 Nov X-TA Final exam review.
10 Tue 18 Nov A view of where algebra goes from here. Final Exam Review