Fall 2013
This is the website for MATH 672, Vector spaces, for the Fall 2013 semester. Scroll down for a continuously updated schedule.

Important data to keep in mind:
  • Lectures are MWF 1:25pm-2:15pm, at Purnell Hall 324B
  • Instructor: Francisco-Javier Sayas (here's my website)
  • Office hours: MW after class, and by appointment. (Please, avoid asking questions by e-mail.)
  • Textbook. A (Terse) Introduction to Linear Algebra, by Katznelson & Katznelson. (AMS). We will cover Chapters 1 through 7.

Philosophy
This class is reading-and-writing intensive. You'll be asked to read carefully different sections of the book. In class, we'll be working on problems and clarifying concepts, but you will not be getting clean classnotes to work with. (The textbook is where to study from.)
Precision and full rigor in presentation of the proofs is expected of all the students. Most of the problems will be about concepts and proofs, and there'll be very few exercises carrying a lot of computation. For training purposes, you'll be asked to memorize one particular item (most often a proof) every now and then.
Some additional materials can be found in the materials page of this website.





The schedule
Check often for updates, links and what not. Exercises and concepts marked in italics are more difficult. Take special care to understand the difficult concepts.


Week
Lecture

Section
Description and problems
1

08/28
W

(So you know about linear systems, don't you?) Slides
08/30
F
1.1
Groups and fields
Ex 1.1.2, 1.1.3, 1.1.4
2

09/04
W
1.2

Vector spaces (definition, examples, and basic properties)
09/06
F
Isomorphisms and subspaces
3


09/09
M
1.2
Direct sums and quotient spaces
Ex 1.2.1, 1.2.2, 1.2.3, 1.2.4, 1.2.7, 1.2.8, 1.2.9,1.2.10
09/11
W
1.3

Linear combinations, linear independence and spanning sets
09/13
F
Bases of vector spaces
Quiz #1 (solve a linear system, memorize a proof, explain a proof, define a couple of concepts)
4


09/16
M
1.3
The dimension of a finite dimensional space
Ex 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.3.7, 1.3.10, 1.3.12, 1.3.13
09/18
W
1.4
Linear systems (READING SECTION)
Ex 1.4.1, 1.4.2, 1.4.3., 1.4.7, 1.4.8, 1.4.9.
09/20
F
2.1
Linear operators
Quiz #2 (definitions, one proof, check that something is a basis)
Ex 2.1.2, 2.1.3, 2.1.4
5


09/23
M
2.4
Operators and matrices
09/25
W
2.2
Operator multiplication and the algebra L(V)
Ex 2.2.1, 2.2.2., 2.2.4
09/27
F
2.3
Matrix multiplication and the algebra of square matrices
Quiz #3 (definitions, one proof, the matrix for a linear operator)
[All exercises of Section 2.3 are interesting. Try them.]
6


09/30
M
2.4


Changes of basis
10/02
W

10/04
F
Similarity of matrices and operators
Ex 2.4.1, 2.4.4, 2.4.5, 2.4.6, 2.4.8
7


10/07
M
2.5
Kernel, range, nullity, and rank
Ex 2.5.2, 2.5.3, 2.5.4, 2.5.8, 2.5.9, 2.5.10, 2.5.11, 2.5.12, 2.5.13
10/09
W
3.1

Linear functionals
Take home part of the midterm due
10/11
F
The dual basis
Ex 3.1.1, 3.1.2, 3.1.3, 3.1.5, 3.1.6a, 3.1.8
Quiz #4 (explain a proof, and two exercises)
8


10/14
M

FIRST MIDTERM EXAM (Chapters 1 and 2)
10/16
W
3.2 The adjoint of an operator ...
10/18
F
... and transposition of matrices
Ex 3.2.1, 3.2.2, 3.2.3
9


10/21
M
4.2
Bilinear operators and forms
10/23
W
Multilinear forms
Ex. 4.2.1, 4.2.2, 4.2.3, 4.2.4, 4.2.6, 4.2.7
10/25
F
4.3
Alternating n-forms
Quiz #5

10


10/28
M
4.4
The determinant of an operator
Ex 4.4.1, 4.5.2, 4.5.3, 4.5.4, 4.5.6, 4.5.7, 4.5.8
10/30
W
5.1
Eigenvalues and the characteristic polynomial
Ex 5.1.2, 5.1.3, 5.1.4, 5.1.5, 5.1.6
11/01
F
5.2
Invariant subspaces
Quiz #6

11


11/04
M
5.2
The minimal polynomial for a vector w.r.t. an operator and Cayley-Hamilton's Theorem
Ex. 5.2.2, 5.2.3, 5.2.4
11/06
W
5.3
The minimal polynomial for an operator
Ex 5.3.1, 5.3.3, 5.3.4, 5.3.5, 5.3.6, 5.3.15, 5.3.16, 5.3.17
11/08
F
5.2
Every complex matrix is similar to a triangular matrix
Quiz #7

12


11/11
M

Preview of the Jordan canonical form
11/13
W
6.1
Inner product spaces
11/15
F

SECOND MIDTERM EXAM (Chapters 1 to 5)
(Solutions are available at materials page)
13


11/18
M
6.1

Orthogonality
Take home part of the midterm due
11/20
W
Orthonormal bases and Gram-Schmidt's method
Ex. 6.1.3, 6.1.4, 6.1.5, 6.1.8, 6.1.9, 6.1.14, 6.1.15
11/22
F
6.2
Duality in inner product spaces
Ex. 6.2.1, 6.2.2, 6.2.3, 6.2.4
14

11/25

6.3
The spectral theorem for self-adjoint operators
Ex 6.3.1, 6.3.5, 6.3.6
Thanksgiving week
15

12/02
M
6.4
Normal operators
Quiz #8 due
(Solutions are available at materials page)
12/04
W
6.5
Unitary operators

12/09
FINAL EXAM (COVERS EVERYTHING)