Foundations of Mathematical Physics

Course number: CA-MATH-806

Jacobs University, Fall 2021

News

Contact Information

Instructor: Prof. Sören Petrat
Email: s.petrat AT jacobs-university.de
Office: 112, Research I

Teaching Assistant: Martin Irungu

Time and Place

Class:
Wed. 09:45 - 11:00, WH-8 Seminar
Fri. 09:45 - 11:00, WH-8 Seminar
Tutorial/Office hour:
Fri. 11:15 - 12:30, WH-8 Seminar

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. Note that this class uses gradescope for grading exams, see here for more information. (Note: Just talk to the instructor if you prefer that gradescope is not used for your exam.)

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:

New: Here you can find the final exam and a model solution.

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 15, 2021 Sheet 1 Sep 22, 2021
Sep 22, 2021 Sheet 2 Sep 29, 2021
Sep 29, 2021 Sheet 3 Oct 06, 2021
Oct 06, 2021 Sheet 4 Oct 13, 2021
Oct 15, 2021 Sheet 5 Oct 22, 2021
Oct 22, 2021 Sheet 6 Oct 29, 2021
Oct 29, 2021 Sheet 7 Nov 05, 2021
Nov 05, 2021 Sheet 8 Nov 12, 2021
Nov 12, 2021 Sheet 9 Nov 19, 2021
Nov 19, 2021 Sheet 10 Nov 26, 2021
Nov 26, 2021 Sheet 11 Dec 03, 2021

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. 03, 2021 Introduction and motivation for quantum mechanics; double slit
See Gustafson, Sigal: Ch.s 1.1, 1.2, 1.3.
Sep. 08, 2021 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. 10, 2021 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, 2021 The free Schrödinger equation; 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. 17, 2021 Fourier transform; Schwartz space
See Teufel lecture notes.
Sep. 22, 2021 Schwartz space as a complete metric 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. 24, 2021 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 the Schwartz space in detail, but aims more directly at defining it on L^p).
Sep. 29, 2021 Solution to the free Schrödinger equation in Schwartz space; multiplication and pseudo-differential operators
See Teufel lecture notes.
Oct. 01, 2021 Pseudo-differential operators and convolution; Tempered distributions (dual spaces, examples)
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. 06, 2021 Weak and weak* convergence; Adjoints (Fourier transform, derivatives, multiplication, and convolution for tempered distributions)
See Teufel lecture notes.
Oct. 08, 2021 Solution to the free Schrödinger equation in the sense of distributions; Long-time asymptotics of the free Schrödinger equation and the momentum operator
See Teufel lecture notes.
Oct. 13, 2021 Long-time asymptotics of the free Schrödinger equation and the momentum operator; the free Schrödinger equation in the classical limit
See Teufel lecture notes.
Oct. 15, 2021 Velocity vector field
See Teufel lecture notes. See the book "Dürr, Teufel - Bohmian Mechanics. The Physics and Mathematics of Quantum Theory" for more about the particle law of motion.
Oct. 20, 2021 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. 22, 2021 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).
Oct. 27, 2021 Bounded operators; the Fourier transform on L2
See Teufel lecture notes.
Oct. 29, 2021 Unitary operators; free propagator on L2
See Teufel lecture notes.
Nov. 03, 2021 Sobolev spaces; unitary groups and their generators
See Teufel lecture notes.
Nov. 05, 2021 Translation operator and its generator; Riesz Representation Theorem
See Teufel lecture notes.
Nov. 10, 2021 Self-adjoint operators; bounded generators
See Teufel lecture notes.
Nov. 12, 2021 Unbounded operators; Kato-Rellich
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, 2021 Mean-field dynamics for bosons: Hartree Theory
A good introductory paper is Pickl - A simple derivation of mean field limits for quantum systems.
Nov. 19, 2021 Mean-field dynamics for bosons: reduced density matrix, counting functional
See Pickl paper.
Nov. 24, 2021 Mean-field dynamics for bosons: Gronwall lemma
See Pickl paper.
Nov. 26, 2021 Mean-field dynamics for bosons: Gronwall lemma
Dec. 01, 2021 Fock space and second quantization; Bogoliubov Theory: dynamics
Dec. 03, 2021 Creation and annihilation operators; Bogoliubov Theory: dynamics
Dec. 22, 2021 Final exam

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