Complex Analysis

(15-Math-601)

Riemann sphere, Möbius transformations, Cauchy-Riemann equations, Cauchy's Theorems & Integral Formulas, Argument Principle, The Residue Theorem, Riemann Mapping Theorem, Schwarz Christoffel Formula

Department of

Mathematical

Sciences

This page is a work in progress! (Last revised 25 September 2009)

Instructor Prof David A Herron
810D Old Chem Bldg, 556-4075
My Office Hours
Mon 2-3, Wed 12:30-2:00
Links to pdf files for my class notes and a list of problems. Problem Session
Mon 1:00-1:50 305 Zimmer

Textbooks There are zillions of books about Complex Analysis available in the Geo-Math-Physics Library. I have put a number of these on open reserve---if you check one out at the end of the day, you can keep it over night. Below is a short list of texts which I think are pretty good. For the most part, I will follow Ahlfors. The books by Carathéodory are very geometric, which I quite like. The book by Greene & Krantz is interesting and takes a novel approach. The books by McGehee and Palka are elementary with lotsa details presented. The books by Greene & Krantz, McGehee, and Palka are all loaded with good problems.
A Ahlfors Complex Analysis (third edition)
C Carathéodory Theory of Functions (of a complex variable) Vols. I & II (second edition)
GK Greene & Krantz Function Theory of One Complex Variable (second edition)
M McGehee An Introduction to Complex Analysis
P Palka An Introduction to Complex Function Theory

General Syllabus Chapters: 1-4 in A; 1-3,6 in GK; 1-3 in M; I-V,IX in P

Course Goals First and foremost, this is a course geared towards teaching you to think, act, and problem solve like a mathematician. Of particular importance, to me, is your acquiring the ability to communicate mathematical ideas effectively. This means learning how to read, and especially to write, mathematical proofs. We shall accomplish this in the guise of studying elementary complex analysis and the roots of geometric function theory. A subgoal, at least for some of you, is preparation for the preliminary PhD examination in complex analysis; I will have more to say about this in spring quarter (at which time I will run a prelim practice problem session).

Grades Your final course grade will be determined from your performance on midterm exams, a final exam, your homework scores, and class and problem session participation. Roughly speaking, an A means your work is at the PhD level, a B indicates masters level work, and anything less describes work which is not at the graduate level.

Homework & Problem Session I have a long list of suggested problems for you to solve. I plan to have a weekly hour long (90 minutes if possible:-) problem session. Here I will expect you, the students, to present solutions to certain of the homework problems. We can also talk about other problems and/or topics from the lectures. On the first day of class we will decide when to hold the problem session. I will also ask you write up and hand in solutions to certain exercises; these will be graded and returned to you. See below for due dates. I'll say more about this in class.

Problem Session Mon 1:00-1:50 room TBA

Below I list information regarding: this week's hot topics, some suggested problems from Ahlfors, and homework.

23-25 Sept This week we start by learning complex arithmetic and elementary function theory with an emphasis on the geometric view point.
28-30 Sept, 2 Oct This week we study mapping properties of the complex linear maps. Then we look at "z squared" and "z+1/z".
5-9 Oct This week we study properties of the complex exponential function and we learn about the complex logarithm function, complex trigonometric functions, and complex powers.
12-16 Oct This week we briefly review plane topology. Then we look at complex derivatives and derive the Cauchy-Riemann equations.
19-23 Oct This week we examine consequences of the Cauchy-Riemann equations. Then we study the Chain Rule and the Inverse Function Theorem.
26-30 Oct This week we learn more about the Cauchy Riemann equations, branches of inverse functions, and the complex differential operators "dee-dee-zee" and "dee-dee-zee-bar". We continue studying complex differentiability and contrast it with real differentiability.
2-6 Nov Midterm exam time!
9-13 Nov This week we continue our initial study of conformal diffeomorphisms.
16-20 Nov This week we study the Riemann sphere .
23-25 Nov This is a short week due to Thanksgiving. We begin our investigation of Möbius transformations.
30 Nov, 1-4 Dec During our last week we study cross ratios, symmetry, and the groups of conformal maps between disks and/or half-planes.

Here are suggested problems for each indicated section in Ahlfors. In general you should try to solve all of the problems in Ahlfors, especially if you are planning to take the preliminary examination in Complex Analysis; but, be aware that some of Ahlfors' problems require some ingenuity. As I mentioned above, the other books also have many many good problems, many of which are routine.

Below is the assigned homework with due dates. (Here, again is a link to a pdf file for a list of these homework problems). The "Problems To Hand In" are to be written up and handed in before class on the indicated dates. The "For Session" problems will be discussed in that week's problem session. After the due date, you can find outlines for solutions (at least for some of the problems) by clicking the appropriate problem number.
Due Dates Problems To Hand In For Session
23,25 Sept No Class First Day 4 No Session
28,30 Sept; 2 Oct 7 9 12(a) 2--10
5,7,9 Oct 23 24 22 14-21, 25-29
12,14,16 Oct 34 36 32,39 29-31,33,35,37,38,41,42
19,21,23 Oct 44 54 46 37,43,47,48,53,55
26,28,30 Oct 67 60 72,73 58,61,62,64-66,68-72
2,4,6 Nov MidTerm 75 No Session
9,11,13 Nov 78 Vets Day 87,88 77,80,83,86, Ahlfors/p.72/2,3
16,18,20 Nov 90 93 95,98 83,91,92,94,96,97
23,25,27 Nov 100,103,106 all due Wed Trky Day 94,99,101,102,104,105
30; 2,4 Dec 104, 109, 124 all due Fri (16,17,27),30,31,94,101,108,111-113
11 Dec Final Exam 1:30-3:30 114-129