Fourier Analysis and its Applications
Fall 2017

All the notes are written by the Teaching Assistant (Yikun Zhang). If you have any questions or find out any mistakes, feel free to email me at yikunzhang@foxmail.com. Thank you in advance!
Instructor: Professor Lixin Yan (Chair of Mathematics) (mcsylx@mail.sysu.edu.cn)

Office: Room 702 (School of Math)

Contact: 020-84110123

TA: Yikun Zhang (yikunzhang@foxmail.com)

TA Office hours: Tuesday 16:00-17:30

TA Office location: Yat-sen Honor College Underground Study Room
Class Time and Location:

Thursday Section 5-6 ( 14:20--16:00 )

Class will be held in Room 416 located in the building of the School of Mathematics.

Class Description:

This seminar-based course is designed for the sophomores of the Applied Mathematics Group at Yat-sen Honor College. All the enrolled students will alternatively deliver lectures to the instructor and other fellow students with the help of the textbook. (See below for the intended textbook.)

Students are encouraged to refer to other textbooks and related materials when preparing their own lectures. Moreover, students are welcome to discuss Math problems with the instructor, the teaching assistant, and other fellow students.

Textbook: Fourier Analysis: An Introduction (Written by Elias M. Stein and Rami Shakarchi)

The photocopied version of the textbook is available on Amazon, China. The original price for one book is 59 RMB, while some discounts would be made on Amazon.
Grading:

Lecture Performance + Reading Report + Homework
Class Schedule:

The lecture will meet once a week throughout the semester. Office hours schedule and exercise class will be announced in the formal sections.

Week Lecturer Textbook Notes
1 Prof.Lixin Yan & Yikun Zhang Introduction to Fourier Analysis Lecture 1 Slide
2 Qiwen Zhou & Yue Hu Sec 2.1
3 Sisi Gai & Dan He Sec 2.2
4 Jian Yao & Minghan Dai Sec 2.3 & Sec 2.4
5 National Day Holiday and Mid-autumn Festival (No class)
6 Chongshan Xie & Kaixi Wu Sec 2.5 & Sec 1.2
7 Qiwen Zhou & Yue Hu Sec 3.1
8 Sisi Gai & Dan He Sec 3.2
9 Jian Yao & Minghan Dai Sec 4.1 & Sec 4.2 A master thesis about Weyl's Equidistribution (Retrieved from the Internet by Yikun Zhang)
10 Mid-term Exam Week (No class)
11 Chongshan Xie & Kaixi Wu Sec 4.3 & Sec 4.4 I found two related papers about examples and proofs of continuous but nowhere differentiable functions. Paper A is interesting and easy to understand, while Paper B is more difficult and requires some knowledge of the Lebesgue Theory and Fourier Transform. I hope that these two paper can boarden your knowledge in Classical Analysis. (Yikun Zhang)
12 Qiwen Zhou & Yue Hu Sec 5.1
13 Sisi Gai & Dan He Sec 5.1, Sec 5.2
14 Jian Yao & Minghan Dai Sec 5.2 & Sec 5.3
15 Chongshan Xie & Kaixi Wu Sec 5.3 & Sec 5.4
16 Qiwen Zhou & Yue Hu Sec 7.1
17 Sisi Gai & Dan He Sec 7.1.3 (FFT)
18 Jian Yao & Minghan Dai Sec 7.2.2, 7.2.3 Results on the Convergence of Fourier Series (A summary of the main reults of the book) (Retrieved from the Internet by Yikun Zhang)
19 Chongshan Xie & Kaixi Wu Sec 7.2.4, 7.2.5 Supplementary materials for finite Fourier analysis (Retrieved from the Internet by Yikun Zhang)
1 (Spring term) Qiwen Zhou & Yue Hu Sec 6.1, 6.2
2 (Spring term) Sisi Gai & Dan He Sec 6.3
3 (Spring term) Jian Yao & Minghan Dai Sec 6.4, 6.5

Homework:

Besides some reading assignments, a small amount of homework may be assigned in some formal lectures. The homework assignment is due on every Thursday before the lecture. The teaching assistant will grade the homework and post the solutions after the deadline of the homework.

Week Homework Reading Assignments Solutions
1 Chapter 2 Ex.16 Sec 2.1, Sec 2.2, Appendix Solution 1, Weierstrass's proof, Berstein's proof
2 Reinforce the understanding of Theorem 1.7 in the Appendix, Chapter 2 Ex.2 & Ex.9 Appendix, Sec 2.2, Sec 2.3 Solution 2
3 Chapter 2 Problem 1 Appendix Lemma 1.5, Sec 2.3, Sec 2.4 Solution 3
4 Chapter 2 Ex.15 & Problem 2, Chapter 1 Ex.10 Sec 2.5, Chapter 1 Solution 4
5 National Day Holiday and Mid-autumn Festival (No class)
6 Chapter 2 Ex.13, Chapter 2 Problem 3 (Challenging, No Due) Sec 3.1, Chapter 1 Solution 5
7 Chapter 3 Ex.2, Ex.5, Ex.7, Problem 1 (Challenging, No Due) Sec 3.2 Solution 6
8 Chapter 3 Ex.11 Ex.16 Sec 4.1 Solution 7
9 No homework (Prepare for mid-term exams of other courses) Review what we have learned
10 Mid-term Exam Week (No class)
11 Chapter 4 Ex.4, Ex.7, Ex.10 Sec 5.1 Solution 8
12 Chapter 5 Ex.1, Ex.5, Ex.7 Sec 5.1, 5.2 Solution 9
13 Chapter 5 Ex.9, Ex.10, Ex.12 Sec 5.2, 5.3 Solution 10
14 Chapter 5 Ex.11, Ex.14, Ex.15 Sec 5.3, 5.4 Solution 11
15 Chapter 5 Ex.21, Ex.22 Preview the definition of (abelian) groups, homomorphism, and character Solution 12
16 Chapter 7 Ex.1, Ex.3, Ex.10, Ex.11 Search the Internet for some applications of FFT (Fast Fourier Transform) Solution 13
17 Chapter 7 Ex.5, Ex.8, Ex.9 Sec 7.2 Solution 14
18 Chapter 7 Ex.12, Ex.13 Sec 7.2, Chapter 6 Solution 15
19 No homework (Good luck for your final exams of other courses) Chapter 6
1 (Spring term) Chapter 6 Ex.2, Ex.4, Ex.5 Sec 6.3 Solution 16, Some detailed discussions on the volume and surface area of an n-dimemsional hypersphere (Supplementary materials for Exercise 4. I retrieved from the Internet. Yikun Zhang)

Interactive Webpage for Weyl's Equidistribution Theorem:

To illustrate the correctness of Weyl's equidistribution theorem, we rely on R Shiny to visualize the theorem on [0,1) interval and display its geometirc interpretation. See the web page for detail.
The raw R code for the R Shiny webpage is available at Yikun's Github (Weyl-s-Equidistribution Repository)
Links:

Here we provide some links of biographies of some famous mathematicians who made great contributions to the development of Fourier Analysis.
Fourier , Cauchy , Dirichlet , Poisson , Plancherel , Lebesgue

Maintained by Yikun Zhang