### Vorlesung: Pseudodifferential operators (PsiDO) (SoSe 2021)

[UPDATE 25.02.2021:] Due to the present situation, this course will be online (uploaded videos, lecture notes; all details on uni2work).
It will start 13 April 2021 (as planned).
For updated information, check back here, on LSF, and on uni2work (where all material will be uploaded).
A brief video introduction can be found here.

Lecture (Vorlesung):
Tue 08-10: Online (videos) and via Zoom; see uni2work.   LSF

Exercises (Übungen):
There are NO exercises!

Synopsis (Kurzbeschreibung):
The theory of pseudodifferential operators arose in the 1960's as a tool in the study of elliptic partial differential equations (the Laplace equation, Poisson equation, Dirichlet and Neumann boundary value problems etc.). Such operators are a generalisation of Partial Differential Operators (PDO's), and they have since then become a strong and useful tool in many other areas of analysis, such as Harmonic Analysis, Spectral Theory, and Index Theory for elliptic operators on manifolds (they are an important ingredient in many proofs of the Atiyah-Singer Index Theorem).

This course will give an elementary introduction to the theory of pseudodifferential operators and their properties. It will include an introduction to the Fourier transform, (tempered) distributions, and Sobolev spaces, which are by themselves very useful tools.

Audience (Hörerkreis):
Master students of Mathematics (WP 17.2, 18.1, 18.2, 44.3, 45.2, 45.3), TMP-Master.

Credits:
3 ECTS.

Prerequisites (Vorkenntnisse):
Analysis I-III. Basic knowledge of Functional Analysis and/or Partial Differential Equations is helpful, but not required.

Language (Sprache):
English. (Die mündliche Prüfung kan auch auf Deutsch gemacht werden).

Exam (Prüfung):
There will be an oral exam (dates to be announced) (Es wird eine mündliche Prüfung geben).
The exam will be online. See separate webpage (uni2work).

Content (Inhalt):
1. Schwartz functions (S) and tempered distributions (S')

2. The Fourier transform on S and S'

3. Sobolev spaces

4. Pseudodifferential symbols

5. Oscillatory integrals

6. Pseudodifferential operators (ΨDO's)

7. The action of ΨDO's on S, S', and Sobolev spaces

8. Global regularity of elliptic PDO's (and ΨDO's)

9. Gårding's inequality

10. Applications

Literature:
In uni2work you will find a copy of the notes from the lecture.
Above you will find a short description of the content of the lecture.
The lecture will mainly follow the book by X. Saint-Raymond mentioned below.