Foundations of Mathematical Physics

Course number: CA-MATH-806

Constructor University, Fall 2023

News

Contact Information

Instructor: Prof. Sören Petrat
Email: spetrat AT constructor.university
Office: 112, Research I

Teaching Assistant: Gandeeb Bhattarai

Time and Place

Class:
Wed. 09:45 - 11:00, EH-8 Seminar
Fri. 17:15 - 18:30, EH-8 Seminar
Tutorial/Question Session:
Thu. 19:15 - 20:30, online on MS Teams

Textbooks

Much of the first part of class material follows the lecture notes by Stefan Teufel, with his kind permission:

These lecture notes have been translated to English, slightly extended, and extended with the material from the class "Advanced Topics in Quantum Mechanics" by Marcello Porta:

The standard reference for functional analysis for mathematical physicists (much of the class material is based on selected material from this book):

Other good books are:

A very good book for some of the Analysis background is:

Table of Contents

Chapter 1: Introduction
1.1: Motivation
1.2: Single Particle QM
1.3: QM for Many Particles

Chapter 2: The Free Schrödinger Equation
2.1: Fourier Transform on S
2.2: Tempered Distributions
2.3: Long-time Asymptotics and the Momentum Operator

Chapter 3: A more general Setting for the Schrödinger Equation
3.1: Hilbert and Banach Spaces
3.2: Unitary Groups and Their Generators
3.3: Self-adjoint Operators

Chapter 4: Bose-Einstein Condensation
4.1: The Ideal Gas
4.2: Dynamics and the Nonlinear Schrödinger Equation
4.3: Fock Space and Second Quantization
4.4: Bogoliubov Theory

Grading

The grade is only based on the final exam. There is the possibility for bonus points (up to 10% in the percentage grading scheme), see below.

Exams

There will be one final exam and one make-up final exam. All topics discussed in class are relevant for the exams.

For practice, here are a midterm and a final exam from a mathematical physics class I taught in 2018. Note that there the last few classes were about unbounded operators and self-adjointness instead of mean-field dynamics:

Here you can find the final exam and a model solution from 2021.

Homework Sheets

There will be regular homework assignment. These are an integral part of the coursework and working on the exercise sheets consistently is the best preparation for the exam. As an additional motivation to work on the homework sheets there are bonus points. These are obtained in the following way: An average homework grade (in percentage scale) is computed out of all but the two worst homework sheets; dividing this by 10 gives the bonus (i.e., it can be at most 10%). Important: The bonus cannot change a failing grade into a passing grade; e.g., if you got a total bonus of 10% but only 35% in the exam, you have still failed the class with this 35% grade.

The homeworks can be handed in on the due date either in class, or they can be put into the mailbox at the entrance of Research I (on the left after you enter through the main entrance).

Date Sheet Number Due Date
Sep 08, 2023 Sheet 1 Sep 20, 2023
Sep 20, 2023 Sheet 2 Sep 27, 2023
Sep 27, 2023 Sheet 3 Oct 04, 2023
Oct 04, 2023 Sheet 4 Oct 11, 2023
Oct 11, 2023 Sheet 5 Oct 18, 2023
Oct 18, 2023 Sheet 6 Oct 25, 2023
Oct 25, 2023 Sheet 7 Nov 01, 2023
Nov 01, 2023 Sheet 8 Nov 09, 2023
Nov 08, 2023 Sheet 9 Nov 16, 2023
Nov 15, 2023 Sheet 10 Nov 23, 2023
Nov 22, 2023 Sheet 11 Nov 30, 2023
Nov 29, 2023 Sheet 12 Dec 07, 2023

Class Schedule

Will be updated while class is progressing.

Below, please click on the date to download the lecture notes of this day.

(Note that the book references given below offer only a rough orientation. Sometimes, only parts of a particular chapter are covered in class.)

Date Topics
Sep. 06, 2023 Introduction and motivation for quantum mechanics; double slit experiment
See Gustafson, Sigal: Ch.s 1.1, 1.2, 1.3.
Sep. 08, 2023 Introduction: Schrödinger equation for a single and many particles; brief comparison to classical mechanics
See Teufel/Porta lecture notes, Ch. 1 Einleitung; see also Gustafson, Sigal Ch. 1.4.
Further literature:
Sep. 13, 2023 Introduction: bosons and fermions; time-independent Schrödinger equation; the Hamiltonian for non-relativistic electrons
More about the derivation of the boson-fermion alternative in 3 dimensions can be found in Chapter 8.5 of the book "Bohmian Mechanics - The Physics and Mathematics of Quantum Theory" by Dürr and Teufel.
More about ground states and a general brief introduction to quantum mechanics can be found in the book "The Stability of Matter in Quantum Mechanics" by Lieb and Seiringer; see Chapters 1 and 2 for the general introduction, and specifically the beginning of Chapter 2.2 for more about ground states and ground state energy.
Sep. 15, 2023 L^p spaces; Lebesgue integral
See Teufel/Porta lecture notes; see Lieb/Loss Ch. 2.1 for more background on Lp spaces; see Reed, Simon - I Functional Analysis, Ch. I Preliminaries for background on measure theory and the Lebesgue measure in particular.
Sep. 20, 2023 Fourier transform
See Teufel lecture notes.
Sep. 22, 2023 Schwartz space
See Teufel lecture notes; see also Reed, Simon - I Functional Analysis, parts of Chapter V.1 and the beginning of chapter V.2.
Sep. 27, 2023 Schwartz space as a complete metric space; Properties of the Fourier transform on Schwartz space
See Teufel lecture notes; see also Reed, Simon - I Functional Analysis, Ch. IX The Fourier Transform; see also Lieb, Loss Ch. 5 The Fourier Transform (this book does not discuss the Fourier transform on Schwartz space in detail, but aims more directly at defining it on L^p).
Sep. 29, 2023 Properties of the Fourier transform on Schwartz space
See references above.
Oct. 04, 2023 Solution to the free Schrödinger equation in Schwartz space
See Teufel lecture notes.
Oct. 06, 2023 Multiplication and pseudo-differential operators and convolution
See Teufel lecture notes.
Oct. 11, 2023 Tempered distributions (dual spaces, examples), weak and weak* convergence, adjoints
See Teufel lecture notes; see also Reed, Simon - I Functional Analysis, Ch. V.3 Functions of rapid decrease and the tempered distributions; see also Lieb, Loss, Ch. 6, where the dual space of C_c^\infty is discussed.
Oct. 13, 2023 Adjoints (Fourier transform, derivatives, multiplication, and convolution for tempered distributions); Solution to the free Schrödinger equation in the sense of distributions
See Teufel lecture notes.
Oct. 18, 2023 Long-time asymptotics of the free Schrödinger equation and the momentum operator
See Teufel lecture notes.
Oct. 20, 2023 Velocity vector field; Hilbert and Banach spaces
See Teufel lecture notes. For more on Hilbert and Banach spaces, see Reed, Simon - I Functional Analysis, Ch. II: Hilbert Spaces and Ch. III: Banach Spaces. See the book "Dürr, Teufel - Bohmian Mechanics. The Physics and Mathematics of Quantum Theory" for more about the particle law of motion.
Oct. 25, 2023 Hilbert and Banach spaces
See Teufel lecture notes. For more on Hilbert and Banach spaces, see Reed, Simon - I Functional Analysis, Ch. II: Hilbert Spaces and Ch. III: Banach Spaces.
Oct. 27, 2023 Hilbert and Banach spaces; bounded operators
See Teufel lecture notes; see also Reed, Simon - I Functional Analysis, Ch.s VI.1 and VI.2 (Bounded Operators).
Nov. 01, 2023 Bounded operators; Fourier transform on L2; unitary operators; free propagator on L2
See Teufel lecture notes.
Nov. 03, 2023 Sobolev spaces; unitary groups and their generators
See Teufel lecture notes.
Nov. 08, 2023 Translation operator and its generator
See Teufel lecture notes.
Nov. 10, 2023 Riesz Representation Theorem; Self-adjoint operators
See Teufel lecture notes.
Nov. 15, 2023 Bounded generators; Unbounded operators
See Teufel lecture notes. For further reading: see Reed, Simon - I Functional Analysis, Ch.s VIII.1 and VIII.2 (Unbounded Operators); and Reed, Simon - II Fourier Analysis, Self-adjointness, Ch.s X.1 and X.2 (Self-adjointness and the Existence of Dynamics).
Nov. 17, 2023 No class
Nov. 22, 2023 Unbounded operators; Kato-Rellich; Friedrichs extension
See Teufel lecture notes.
Nov. 24, 2023 (Session 24) Mean-field dynamics for bosons: Hartree Theory; reduced density matrix, counting functional
A good introductory paper is Pickl - A simple derivation of mean field limits for quantum systems.
Nov. 29, 2023 Mean-field dynamics for bosons: reduced density matrix, counting functional
See above.
Dec. 01, 2023 Mean-field dynamics for bosons: Gronwall lemma
See above.
Dec. 06, 2023 Mean-field dynamics for bosons: Conclusion and Coulomb interaction
See above. See also some previous class notes on Bogoliubov theory: Session 26, 2021, Session 27, 2021.
Dec. 15, 2023 Final exam

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