Math 4555 (Complex Variables), Fall 2025



Course Information
Instructor Class Times Office Hours
Evan Dummit
edummit at northeastern dot edu
MW 2:50pm-4:30pm
241 Richards Hall
MW 1:30pm-2:30pm
W 4:45pm-5:45pm
571 Lake Hall
For detailed information about the course, please consult the 4555 Course Syllabus. Note: any information given in class or on this webpage supersedes the written syllabus.
Problem Session Leader(s) Recitation Times + Locations
Jordan Martino Day, time, and location TBA
We will use Piazza for any course-related discussion: here is the Piazza page.
All homework assignments will be posted on this webpage (see below).
Homework assignments will be submitted via Canvas. Please submit scans of your homework pages by 11:59pm Eastern on the due date. Late assignments may be penalized at the grader's discretion.
Use of large-language models ("generative AI", such as ChatGPT or Claude) or equivalent technology in any manner is expressly prohibited in this course. This includes, but is not limited to, summarizing course information, asking for hints or solutions to course assignments, and general information retrival on course topics. Ask questions during class, in office hours, on Piazza, during problem sessions, or via email instead.
The instructor will write lecture notes for the course (see below) in lieu of an official textbook as the semester progresses. Reference texts are available upon request.


Homework Assignments and Exams
Some Tips on Problem Solving are available as suggestions for the homework assignments.
Homework assignments to be posted here.


Course notes to be posted here.
Handouts / Lecture Notes
Handout Topics


Tips For Success In This Course
Attend Lecture Missing lecture is a bad idea! If for any reason you cannot make it to a class, you should review the notes and watch the lecture recording. You are responsible for all material covered in lecture.
Attend Problem Sessions There are weekly problem sessions run by the course's TAs. The goal of the problem sessions is to provide you a location where you can work with other students on assignments, and also get assistance from a TA. It is highly recommended to attend at least one problem session per week to work on the homework problems.
Read the Lecture Notes The lecture notes are a comprehensive source of material for the course. The notes are intended as review material, although many students like to read them as preparation before attending the lecture on the corresponding topics. Please note that the electronic notes are not identical to the material covered in class: this is by design, so as to provide you a slightly different perspective on the material.
Solve Homework Problems Much of the learning in this course will take place as you solve the homework problems. Like many other activities, problem-solving and proof-writing are things that are learned by doing them, not by hearing someone else tell you about them or reading about them in a book. As such, the homework assignments are an integral part of the course, and are fundamental to learning the material. It is highly recommended that you look over the homework assignments as soon as they are available, and work on them well in advance of the deadline: many problems will take substantial time and effort to solve, and you should expect to spend as much time as you need to finish the assignments.
Attend Office Hours Office hours are specifically reserved for you to receive individual, one-on-one help from the instructor. Office hours will be the most effective when you have already put in effort to learn the material on your own (including trying to solve the homework problems), and when you come in with a list of specific questions or topics you are struggling with.


Course Schedule
The schedule is subject to change! All sections refer to the course lecture notes.
Week Schedule
Week of Sep 1
(class starts 9/3)
§1.1.1: Complex Arithmetic
§1.1.2: Polar and Exponential Forms
No homework this week.
Week of Sep 8 §1.1.3: Topology of C
§1.2.1: Limits
§1.2.2: Complex Differentiation
§1.2.3: The Cauchy-Riemann Equations
§1.2.4: Holomorphic Functions and Angles
Homework #1 due Thursday 9/11 via Gradescope.
Week of Sep 15 §2.1.1: Formal Power Series
§2.1.2: Formal Laurent Series
§2.2.1: Convergent Sequences and Series
Homework #2 due Thursday 9/18 via Gradescope.
Week of Sep 22
§2.2.2: Convergent Power Series
§2.2.3: Continuity and Differentiability of Power Series
§2.3.1: Exponentials and Trigonometric Functions
§2.3.2: Complex Logarithms
Homework #3 due Thursday 9/25 via Gradescope.
Week of Sep 29 §3.1.1: Line Integrals in C
§3.1.2: Evaluating Line Integrals
§3.1.3: Path Independence
Homework #4 due Thursday 10/2 via Gradescope.
Week of Oct 6 §3.2.1: Cauchy's Integral Theorem via Green
§3.2.2: Deformation of Contours
Homework #5 due Thursday 10/9 via Gradescope.
Week of Oct 13
(no class 10/13)
§3.2.3: Integration of Power Series
§3.2.4: Winding Numbers
Homework #6 due Thursday 10/16 via Gradescope.
Week of Oct 20 §3.2.5: Cauchy's Integral Formula
§3.2.6: Higher Derivatives and Series Expansions
§4.1.1: The Cauchy Estimates
Homework #7 due Thursday 10/23 via Gradescope.
Week of Oct 27 §4.1.2: Entire Functions, Liouville's Theorem
Review for midterm exam
MIDTERM EXAM Wednesday 10/29 in class.
No homework this week.
Week of Nov 3 §4.1.3: The Maximum Modulus Principle
§4.2.1: Laurent Series Expansions
§4.2.2: Zeroes of Holomorphic Functions
§4.2.3: Removable Singularities, Poles, and Essential Singularities
Homework #8 due Thursday 11/6 via Gradescope.
Week of Nov 10 §4.3.1: Residues, The Residue Theorem
§4.3.2: Residue Integrals: Circular Contours
§4.3.3: Residue Integrals: Circular Contours with Detours
§4.3.4: Residue Integrals: Other Contours (Rectangles, Keyhole)
Homework #9 due Thursday 11/13 via Gradescope.
Week of Nov 17 §5.1.1: Counting Zeroes and Poles
§5.1.2: Rouché's Theorem
§5.1.3: The Open Mapping Theorem, Local Invertibility
Homework #10 due Thursday 11/20 via Gradescope.
Week of Nov 24
(no class 11/26-11/30)
§5.2.1: The Point at Infinity and the Extended Complex Plane
§5.2.2: Fractional Linear Transformations
No homework this week.
Week of Dec 1
(class ends 12/3)
§5.2.3: Conformal Mapping
§5.2.4: Analytic Continuation
In-Class Component of Final Exam Wednesday 12/3 in class.
Homework #11 due Thursday 12/4 via Gradescope.
Take-Home Component of Final Exam due Thursday 12/11 via Gradescope.