MATH 421 – Abstract Algebra

Spring 2011

 

 

Professor: Dr. Janet Vassilev
Office: SMLC 324

Office Hours:  MWF 2-3 pm and by appointment.
Telephone:
(505) 277-2214
email: jvassil@math.unm.edu

webpage: http://www.math.unm.edu/~jvassil

Text :  A First Course in Abstract Algebra, 7th Edition  By John Fraleigh.

Course Meetings:  The course lectures will be held in SMLC 356 on Mondays, Wednesdays and Fridays at 1-1:50 pm. 

Topics:  Theory of fields, algebraic field extensions, advanced group theory and Galois theory.

Daily Quizzes (100 points):  The first 5 minutes of everyday (excluding exam days) will consist of an open notebook quiz on the concepts of the previous lecture.  The quizzes will be worth 5 points each.  I will drop your 4 lowest quizzes and average the remaining quizzes to obtain a score out of 100.

Homework (200 points):  Homework will be assigned weekly on Wednesdays and will be collected the following Wednesday at the beginning of class.  Homework will not be graded unless it is written in order and labeled appropriately.   The definitions and theorems in the text and given in class are your tools for the homework proofs.  If the theorem has a name, use it.  Otherwise, I would prefer that you fully describe the theorem in words that you plan to use, than state “by Theorem 3”.  Each week around 4 of the assigned problems will be graded. The weekly assignments will each be worth 20 points.  I will drop your lowest two homework scores and the remaining homework will be averaged to get a score out of 200. 

Exams (400 points):  I will give two midterms (100 points) and a final (200 points). There are no make up exams. If a test is missed, notify me as soon as possible on the day of the exam. For the midterms only, if you have a legitimate and documented excuse, your grade will be recalculated without that test.  The Midterms are tentatively scheduled for Monday, February 21 and Friday, April 1.  The Final is on Friday, May 13, from 12:30 pm-2:30 pm. 

Grades:  General guidelines for letter grades (subject to change; but they won't get any more strict): 90-100% - A; 80-89% - B; 70-79% - C; 60-69% - D; below 60% - F.  In assigning Final Grades for the course, I will compare your grade on all course work (including the Final) and your grade on the Final Exam.  You will receive the better of the two grades.

Tentative Schedule (for Dr. Vassilev’s Abstract Algebra):

Date

Section

Topic

Homework

1/19

23

Review of factoring polynomials

 

1/21

23

Factoring polynomials 

Quiz 2:  What is an irreducible polynomial in F[x]?

1/24

27

Ideals in F[x]

Quiz 3:  What is the content of a polynomial f(x) in Q[x]?

1/26

27, 26

Unique Factorization and Factor Rings

Homework 1:  Section 23: 3, 9, 12, 21, 27, 28; Section 27: 5, 8, 32

Quiz 4: Is 4x^2+12x+15 in Z[x] irreducible?

1/28

29

Extension Fields

Quiz 5: What is the property of ideals that is important in making R/I a ring when R is a ring and I is an ideal?

1/31

29

Extension Fields

Quiz 6: What is an extension field of a field K?

2/2

 

 

Class canceled due to snow closure

2/4

 

 

Class canceled due to natural gas closure

2/7

30

Vector Spaces

Quiz 7: Give an example of an algebraic extension of Q.

2/9

31

Algebraic Extensions

Homework 2: Section 29: 4, 8, 10, 14, 23, 25, 30, 31, 33; Section 30: 4, 9, 15

Quiz 8: Is a spanning set of a vector space necessarily linearly independent?

2/11

31

Algebraic Extensions

Quiz 9: Is a finite field extension always algebraic?

2/14

31

Zorn’s Lemma and Algebraic Closure

Quiz 10: If E is an algebraic extension, what is \overline{F}E?

2/16

33

Finite Fields

Homework 3: Section 31: 4, 10, 19, 23, 27, 29, 30, 32, 36

2/18

33

Finite Fields

Quiz 11:  If [E:F]=n and F has q elements, how many elements does E have?

2/21

34

Isomorphism Theorems

Quiz 12: F_{p^n} is contstructed inside what field?

2/23

35

Series of Groups

Quiz 13: State the 2nd Isomorphism Theorem.

2/25

 

Review

Quiz 14: Is {e} < {e,f_1} <S_3 a subnormal series?

2/28

 

Midterm 1

 

3/2

35

Series of groups

Homework 4: Section 33: 2,8,9,12; Section 34: 4, 9; Section 35 4,5

3/4

35

Series of groups

Quiz 16: Give isomorphic refinements of the normal series (0) < (5) <Z_20 and (0)<(4)<(2)<Z_20.

3/7

35

Sylow Theorems

Quiz 17: Give an example of a composition series.

3/9

36

Sylow Theorems

Homework 5: Section 35: 8, 12, 13, 17, 18, 28, 29; Section 36: 2, 4, 6, 10, 12, 13, 16

Quiz 18: In a group of order 18, what is the size of the Sylow 3-subgroup?

3/11

36

Sylow Theorems

Quiz 19: In a group of order 50, what does the First Sylow Theorem tell you about the orders of some of the subgroups?

3/21

37

Sylow Theorems

Quiz 20: What are the possible number of Sylow 5-subgroups in a group of order 20?

3/23

39

Free Groups

Homework 6: Section 37: 3, 4, 6, 7; Section 39 1, 2, 4, 10

Quiz 21: Is a group of order 21 necessarily abelian?

3/25

39

Free groups

Quiz 22: Is there a homomorphism f from F[{x,y}] to Z_6 with f(x)=2 and f(y)=3?

3/28

40, 48

Group Presentations, Automorphisms of Fields

Quiz 23: If N is a normal subgroup in G and H_i form a composition series for G, what is a composition series for G/N?

3/30

 

Review

Homework 7: Section 40 1, 2, 4, 8, 13

Quiz 24:

4/1

 

Midterm 2

 

4/4

48

Automorphisms of Fields

 

4/6

48

Automorphisms of Fields

Homework 8: Section 48 4, 8, 10, 12, 20, 29, 34, 36, 37

Quiz 26: What is the fixed field of \sigma mapping Q(\sqrt{26}) to itself via \sigma(\sqrt{26})=-\sqrt{26}?

4/8

49

Isomorphism Extension Theorem

Quiz 27:

4/11

49

Isomorphism Extension Theorem

Quiz 28: What is the partially ordered set that we used in proving the Isomorphism extension theorem?

4/13

50

Splitting Fields

Homework 9: Section 49: 2, 4, 6, 8, 9, 11, 12, 13

Quiz 29: What is the splitting field of x^p-x over Z_p?

4/15

50

Splitting Fields

Quiz 30: Does x^2-30 split over Q(\sqrt{2}, \sqrt{3}, \sqrt{5})

4/18

51

Separable Extensions

Quiz 31: Tell me something special about Z_p(y) and Z_p(y^p)

4/20

51

Separable Extensions

Homework 10: Section 50: 2, 4, 10, 14, 15, 18, 20, 24; Section 51 8, 9, 11, 15, 17, 18

Quiz 32: Is a field with 32 elements perfect?

4/22

52

Totally Inseparable Extensions

Quiz 33: What is the primitive element theorem?

4/25

53

Galois Theory

Quiz 34: Give an example of a normal field extension.

4/27

53

Galois Theory

Homework 11: Section 52: 1, 2, 5, 7; Section 53 2, 8, 14, 15, 16, 17, 19, 23

4/29

56

Insolvability of the Quintic

 

5/2

 

Review

 

5/4

 

Review

 

5/6

 

Review

 

5/13

 

Final exam