Functional Analysis I Autumn 2022

Lecturer
Prof. Dr. Peter Hintz
Course Assistant
Riccardo Caniato
Teaching Assistants
Ata Deniz Aydin, Cosmin Manea, Andrea Nützi, Pieter-Bart Peters
Lectures
Mon10-12
Thu14-16
Exercise classes
Mon9-10
First lecture
22.09.2022
Course Catalogue
401-3461-00L Functional Analysis I

Prerequisites

Solid background on the content of all Mathematics courses of the first two years of the undergraduate curriculum at ETH (most remarkably: fluency with topology and measure theory, in particular Lebesgue integration and \(L^p\) spaces).

Content

Baire category; Banach and Hilbert spaces, bounded linear operators; basic principles: uniform boundedness, open mapping/closed graph theorem, Hahn-Banach theorem; convexity; dual spaces; weak and weak* topologies; Banach-Alaoglu theorem; reflexive spaces; compact operators and Fredholm theory; closed range theorem; spectral theory of self-adjoint operators in Hilbert spaces.

Literature

Michael Struwe. Funktionalanalysis I und II. Lecture notes, ETH Zürich, 2019/20.

Haim Brezis. Functional analysis, Sobolev spaces and partial differential equations. Universitext. Springer, New York, 2011.

Peter D. Lax. Functional analysis. Pure and Applied Mathematics (New York). Wiley-Interscience [John Wiley & Sons], New York, 2002.

Elias M. Stein, Rami Shakarchi. Functional analysis (Volume 4 of Princeton Lectures in Analysis). Princeton University Press, Princeton, NJ, 2011.

Manfred Einsiedler, Thomas Ward. Functional Analysis, Spectral Theory, and Applications. Graduate Text in Mathematics 276. Springer, 2017.

Walter Rudin. Functional analysis. International Series in Pure and Applied Mathematics. McGraw-Hill, Inc., New York, second edition, 1991.

Diary of the lectures

After each lecture, the recording is published here. For further information, check the following information about lecture recording.

You can access all the material concerning the lectures at the following polybox folder.

WeekContents
19.09 / 22.09Normed vector spaces and their basic properties (Struwe 2.1).
26.09 / 29.09Continuous linear maps between normed vector spaces (Struwe 2.2). Quotient spaces (Section 2.3). Hahn-Banach theorem, real and complex version (Struwe 4.1).
03.10 / 06.10Baire category theorem (Struwe 1.3). Applications to functional analysis (Struwe 3.1-3.3).
10.10 / 13.10Closed graph theorem (Struwe 3.3). Hilbert spaces (Struwe 2.4). Duality in Hilbert spaces (Struwe 4.3).
17.10 / 20.10Strongly diverging Fourier series. \(L^p\) spaces as completions.
24.10 / 27.10Fourier transform on \(L^2\) for \(2\pi\)-periodic functions. Definition of weak convergence (Struwe 4.6).
31.10 / 03.11Weak and weak\(^*\) topologies (Struwe 4.6 and 5.3). Reflexivity and separability (Struwe 5.2 and 5.1).
07.11 / 10.11Separation theorems (Struwe 4.5). Convex sets and the weak topology (Struwe 4.6). Reflexivity and weak compactness (lecture notes on polybox).
14.11 / 17.11Milman-Pettis theorem (Brezis 3.7). Adjoint operators and duality (Struwe 6.1 and 6.2). Compact operators (Struwe 6.3).
21.11 / 24.11Examples of compact operators and their applications (lecture notes on polybox). Compactness criteria: Arzelà-Ascoli theorem (with proof) and Frechet-Kolmogorov theorem (without proof) (Struwe 6.3). Applications of the compactness criteria (lecture notes on polybox).
28.11 / 01.12Fredholm operators (lecture notes on polybox). Holomorphic families of operators (lecure notes on Polybox).
05.12 / 08.12Spectral theory: generalities (Struwe 6.5). Spectral theory of compact operators (Struwe 6.7 and lecture notes on polybox).
12.12 / 15.12Spectral theory of compact, self-adjoint operators and related examples. Courant-Fischer-Weyl theorem (Struwe 6.7 and lecture notes on polybox). Functional calculus (lecture notes on Polybox).
19.12 / 22.12Functional calculus and related examples (lecture notes on Polybox).

Exercise classes

Please register and enroll for a teaching assistant in myStudies. The enrollment is needed to attend the exercise class and to hand in your homework.

Assistant Room
Ata Deniz Aydin HG G 26.5
Cosmin Manea ML J 34.1
Andrea Nützi HG G 26.1
Pieter-Bart Peters ML F 40

Exercises

Every Friday, a new problem set is uploaded here. You have seven days to solve the problems and hand in your solutions via the platform SAMUpTool (the precise deadline is the following Friday, no later than 8pm). Your work will be carefully graded and given back to you after a few days. During exercise classes on Monday some of the problems will be discussed.

Assignment dateDue dateProblem setSolution
Fri 23.09. Fri 30.09.Exercise sheet 1Solutions
Fri 30.09. Fri 07.10.Exercise sheet 2Solutions
Fri 07.10. Fri 14.10.Exercise sheet 3Solutions
Fri 14.10. Fri 21.10.Exercise sheet 4Solutions
Fri 21.10. Fri 28.10.Exercise sheet 5Solutions
Fri 28.10. Fri 04.11.Exercise sheet 6Solutions
Fri 04.11. Fri 11.11.Exercise sheet 7Solutions
Fri 11.11. Fri 18.11.Exercise sheet 8Solutions
Fri 18.11. Fri 25.11.Exercise sheet 9Solutions
Fri 25.11. Fri 02.12.Exercise sheet 10Solutions
Fri 02.12. Fri 09.12.Exercise sheet 11Solutions
Fri 09.12. Fri 16.12.Exercise sheet 12Solutions

Getting ready for the exam

You can find a list of exam type problems in the polybox folder of the course, named after "exam-prep.pdf". Such a list will be useful to get ready for the actual exam. Please, see the section "Comments" in the file to gather all the important information about the structure of the exam.