Math 427, Honors Abstract Algebra, Spring, 2006
My information:
Thomas Nevins
357 Altgeld Hall
217.265.6762
nevins@uiuc.edu
Office hours: Tuesdays, noon to 1 p.m. in room 443 Altgeld; Fridays, 3:30-4:45 p.m. in my office (357 Altgeld);
and by appointment
Syllabus (in PDF)
Midterm #1: Friday, February 24 (tentative)
Midterm #2: Friday, March 31 (tentative)
Final Exam: Tuesday, May 9, 8--11 a.m.
Course Summary
This course will give an introduction to the basic objects of modern abstract
algebra: groups, rings, and fields. We'll cover important structure theorems
but will also focus our attention on a deep understanding of a few of the
coolest examples in the subject.
A tentative list of topics:
Groups:
Definition, examples. Subgroups, cosets, normal subgroups and quotient
groups, homomorphisms. Group actions, examples. Orbits, stabilizers under
group actions. Isomorphism theorems. Cayley's theorem. Cauchy's
theorem. Direct products.
Rings:
Definition, examples. Subrings, ideals, quotient rings, homomorphisms.
Isomorphism theorems. Integral domains, fields, prime and maximal ideals.
Geometric meaning of maximal ideals and quotient rings.
Division algorithm, Euclidean domains. PIDs. Field of fractions of a
domain. Modules, structure theorem for f.g. modules over a PID.
Eisenstein criterion. Primes congruent to 1 mod 4 as sums of squares.
Some possible sources of examples:
cyclic groups; (finite) p-groups; dihedral groups; symmetric groups, even
and odd permutations, structure of permutations; matrix groups, especially
SO(3) (and possibly GL(n,C)); finite subgroups of SU(2) (aka
binary polyhedral groups).
Polynomial rings; integers etc.; Gaussian integers; factor rings of
polynomial rings and algebraic subsets of affine space; coordinate rings
of plane conics and cubics. Rings of integers in some (quadratic) number
fields.
A useful web page on groups of small order.
Homework: [Guide to interpretation: T: "tractable," G: "of greater difficulty," V: "very challenging"]
- Homework #1, due Monday, January 23: read Chapter 1 and Sections 2.1-2.4 of
Herstein; do problems 1.1.10 (justify your answers), 1.2.8, 1.2.9, 1.3.1,
1.3.4. Also, tell me an estimate for the number of hours you spent solving and
writing up the homework problems.
- Homework #2, due Monday, January 30: read Sections 2.1-2.8 of Herstein.
Do problems 2.3.1, 2.3.3*, 2.3.6, 2.3.7,
2.3.8*, 2.3.13*, 2.3.21, 2.3.23*, 2.5.1*, 2.5.3*, 2.5.14. Write up and turn
in the ones that have * next to them. Tell me how many hours you spent solving and writing up homework problems.
- Homework #3, due Monday, February 6: do problems 2.3.9, 2.3.11*, 2.3.24*
(also, is the group of 2.3.24 isomorphic to S3? if so, construct
an isomorphism)*, 2.3.26, 2.5.21*, 2.5.27*, 2.5.28, 2.5.29, 2.6.1, 2.6.2*, 2.6.4, 2.6.17*. Write up and turn in the asterisked problems above. Give me a time
estimate. Note: there is a typo in problem 2.6.17, it should read
"...all formal symbols xiyj, i = 0 or 1 and j =0, 1, ..., n-1."
- Homework #4, due Monday, February 13: T: This
problem*, 2.6.21, 2.7.8*, 2.7.10*, 2.7.12; G: 2.6.8, 2.6.12, 2.7.15*; V: none this week.
- Homework #5, due Monday, February 20: T: 2.7.2*, 2.7.4*, 2.7.5, 2.7.18*, G:2.6.13, 2.7.11*, 2.7.16*, parts 1(a, c, d) of the first "supplementary problem" on p. 116, plus write down everything you can about groups of order 8;
V: 2.6.14, and prove that there are two nonisomorphic nonabelian groups of order 20.
- Homework #6, due Friday, March 3: write solutions to the first exam.
- Homework #7, due Wednesday, March 8: these problems.
- Homework #8, due Monday, March 13: Problems 2.12.6, 2.12.7, 2.12.20. Also, prove: if G1, ..., Gn are groups with normal subgroups
H1, ..., Hn respectively, then H1× ... × Hn is a normal subgroup of G1× ... × Gn, and (G1× ...× Gn)/(H1× ... × Hn) is isomorphic to
(G1/H1) × ... ×(Gn/Hn).
- Homework #9, due Wednesday, March 29: in PDF.
- Extra credit homework: read the handout from Chapter 9 of Artin's "Algebra" book, on group representations. Also, do problems 1.2, 1.4, 1.9, 4.2, 4.6, 5.8, 6.3, 9.1 from the end of that Chapter.
- Homework #10, due Wednesday, April 5: write solutions to the
second exam.
- Homework #11, due Wednesday, April 19: do the supplementary midterm problems handed out in class.
- Homework #12, due Friday, April 21, in PDF.
- Homework #13, due Friday, April 28, in PDF.
- Homework #14, due Wednesday, May 3, in PDF.
Solution to problem 6.
Notes:
- Week 2, PDF
- Week 3, PDF
- Week 4, PDF
- Week 5, PDF Note: one lecture this week was "off the cuff," another was by Professor Duursma.
- Group actions: I have no written notes, please see the hand-out from Artin.
- Sylow Theorems, PDF.
- Finitely Generated Abelian Groups, PDF.
- Week 10,
- Week 11,
- Week 12,
- Week 13,
- Week 14,
- Week 15,
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