Theoretische Physik IV: Statistische Mechanik

B.Sc. Physik

Wintersemester 2026/27

Beginning of course

The first class will take place on Wednesday, October 14, 2026. The first tutorials will take place on Wednesday, October 28, and the first sheet will be due on Monday, October 26.

Spacetime

  • Wednesday, 11:30 - 13:00, Hörsaal V57.02, Pfaffenwaldring 57
  • Friday, 11:30 - 13:00, Hörsaal V57.02, Pfaffenwaldring 57

General Information

  • The lecture will be given in German.
  • The registration for the exercise groups will be open from Friday, October 16, 2026, 1:30 PM. To do so, you need the Lecture Key given in the first and second lecture. Note that the registration is only possible from within the university network.
  • If you assign a password at the registration, you can request your current scores here. This is highly recommended as it will allow you to monitor your points.

Recordings of the lectures can be accessed via ILIAS. The recordings should be seen as a service to those of you who cannot come on a specific date (e.g., due to sickness etc.) or want to recap later. However, I highly recommend attending as many lectures as possible, to take advantage of the interactive nature of the classroom and learn with/from your peers.

Examination

There will be a written exam at the end of the course (spacetime to be announced) on the content covered by the lecture. The exam will be 2h and you will be allowed to bring one A4 page (both sides) with handwritten notes.

To qualify for the written exam, you have to pass the exercise class (see below). Students who have already obtained a suitable certificate from another lecturer must have it recognized by December 7, 2026 by sending it via E-Mail to Prof. Scheurer.

Literature

  1. Schwabl, Statistische Mechanik, Springer
  2. Fließbach, Statistische Physik, Spektrum
  3. Nolting, Grundkurs Theoretische Physik 4+6, Springer
  4. Bartelmann, Feuerbacher, Krüger, Lüst, Rebhan & Wipf, Theoretische Physik 4: Thermodynamik und Statistische Physik, Springer
  5. Huang, Statistical Mechanics, John Wiley & Sohns
  6. Landau & Lifschitz, Lehrbuch der Theoretischen Physik V, Akademie Verlag

Topics

Vorwort und Motivation. Das Vielteilchenproblem. Emergenz.

Thermodynamik. Zustandsgrößen. Ideales und van-der-Waals-Gas. Hauptsätze der Thermodynamik. Carnot-Prozess. Entropie. Thermodynamische Potentiale. Response Funktionen. Maxwell-Relationen.

Klassische stochastische Prozesse. Grundlagen der Wahrscheinlichkeitstheorie. Zentraler Grenzwertsatz. Markov-Prozesse. Mastergleichung. Detailliertes Gleichgewicht. H-Funktion. Zwei-Zustands-System. Stochastische Irrfahrt und Diffusion. Fokker-Planck-Gleichung. Langevin Gleichung.

Klassische statistische Mechanik. Fundamentale Prinzipien. Mikrokanonisches, kanonisches, und großkanonisches Ensemble. Entropie. Ideals Gas. Klassischer Gleichverteilungssatz. Klassische Spin-Modelle.

Quantenmechanische Statistische Physik. Dichte-Matrix. Quantenmechanische Ensembles. Ununterscheidbare Teilchen. Ideale Fermigase. Sommerfeld-Entwicklung. Ideale Bosegase. Bose-Einstein-Kondensation. Phononen.

Phasenübergänge. Landau-Theorie der Phasenübergänge. Klassisches Ising Modell. Molekularfeldnäherung.

Je nach Zeit am Ende des Semesters besprechen wir weitere ausgewählte Themen.

You can find the online lecture notes here.

Requirements to pass exercise class

The weekly exercises class will involve: "Virtual presentations": at the beginning of every tutorial, you can indicate on a list which parts of the exercises you have prepared and are willing to present. While everyone will get points for the parts signed up for, only one person will have to present it.

There is one special "lecture-hall sheet": on January 8, 2027, instead of the lecture, you will be given a sheet to solve during the about 1,5 h of the lecture time (in V57.02) – by yourself, without any form of help (no notes, not computer/phone etc.). The questions will be closely related to the previous exercise sheets while compatible with the time constraints. The points of that sheet count just as those of any other normal sheet. We highly recommend that you use this opportunity to test yourself and get feedback (and add points to your total score).

If any question on the exercise lists is not clear enough, please feel free to contact your tutor for clarifications.

In order to pass the exercises, you need at least 66% of the total points; furthermore, every student is required to present at least two times on the blackboard.

Problem Sets

No. Published Due Download Comments
1 19.10.2026 28.10.2026 Problem set 1  
2 26.10.2026 04.11.2026 Problem set 2  
3 01.11.2026 11.11.2026 Problem set 3  

Tutorials

Tutor Room Day Time

Bernhard Putzer (Gruppe 1a)

 5.331 Wed 9:45 AM

Ali Can Yildirim (Gruppe 1b)

 4.342 Wed 9:45 AM

Simon Fell (Gruppe 2)

 5.331 Wed 2:00 PM

Chris Bühler (Gruppe 3a)

 5.331 Thu 11:30 AM

Denis Sedov (Gruppe 3b)

 2.328 Thu 11:30 AM
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