Math 542 (Harmonic Analysis 2)
Spring 2023
Basic information

Instructor: Pablo Shmerkin.

Times: The published times are MWF 12:0012:50, but these may be reviewed at the start of the semester to take into account possible clashes with other courses, etc. Feel free to get in touch if the official times do not work for you.

Office hours: via zoom, times will be published at the beginning of the semester.

Prerequisites: MATH 420/507 and 404/541, or equivalent background in real and harmonic analysis (please contact me in case of any doubts)
Course description
Harmonic Analysis is a core area of modern mathematics with connections to pretty much all mathematical fields, such as PDEs, combinatorics and number theory. In this course we will focus on two (closely connected) problems at the heart of modern analysis: Kakeya and restriction. I will aim to present a variety of ideas and tricks that are used throughout harmonic analysis, such as dyadic pigeonholing and decomposition, induction on scales, the role of curvature and multilinearity, etc. I will try to provide a glimpse of current research as well.
Grading policy
TBA
Tentative topics (subject to revision)

Stationary phase. Dual balls and rectangles. Hausdorff and Minkowski dimension.

The restriction problem. SteinTomas argument. The planar case.

The Kakeya problem: maximal and dimension formulations, and their connections. Restriction implies Kakeya.

Some partial results towards the Kakeya conjecture.Kakeya sets in finite fields.

The LoomisWhitney inequality and Guth's proof of the multilinear Kakeya theorem.
 Introduction to decoupling.

Depending on time and interest, I may add some of the following topics of current research interest: (i) The multilinear to linear argument of BourgainGuth, (ii) The high/low frequency method for tube incidences, (iii) Projection theorems.
Bibliography
There is no required textbook. Much of the material in the course can be found in the books:

Fourier Analysis and Hausdorff Dimension by P. Mattila . Available online through UBC library.

Fourier restriction, decoupling and applications, by C. Demeter. Available online through UBC library.

Lectures on Harmonic Analysis, by. T. Wolff. Available here.
For multilinear Kakeya, we will follow L. Guth's article A short proof of the multilinear Kakeya inequality, available here.