Representation Theory of Finite Groups WS 2024/25


Schedule


Lecture: Wednesdays 12:45 - 13:15 Room 48-538 Lecturer: Prof. Dr Caroline Lassueur
Fridays 10:15 - 11:45 Room 48-538 Lecturer: Prof. Dr Caroline Lassueur
Exercises: Thursdays 12:15 - 13:45 Room 48-438 Instructor: Prof. Dr Caroline Lassueur
Office hour: Upon request


Public holidays / Exceptional schedule:
  • Thursday, the 31st of October: Reformation Day - no lecture

Exam Dates: TBA


Lecture Notes


My lecture notes can be downloaded from the following seafile folder:


Exercises


The exercise sheets can be downloaded from the following seafile folder:


Studienleistung


In order to obtain a Studienleistung the following criteria are fulfilled.

You must hand in to me 3 fully worked out exercises over the semester (1x in weeks 4 to 6, 1x in weeks 7 to 10, 1x in weeks 11 to 14);
  • Your written solutions must be detailed and complete.
  • You need to present orally your solution to me and your fellow students + possibly answer questions


References


Textbooks you can use are the following. However, the lectures do not follow any of them faithfully.
  • [JL01] G. James and M. Liebeck, Representations and characters of groups. See [zbMATH].
  • [Ser77] J.-P. Serre, Linear representations of finite groups. See [zbMATH].
    The original text is:
    [Ser98] J.-P. Serre, Représentations linéaires des groupes finis. See [zbMATH].
  • ([Isa06] M. Isaacs, Character theory of finite groups. See [zbMATH].)
  • [Web16] P. Webb, A course in finite group representation theory. See [zbMATH].
  • [CCNPW85] J.H. Conway, R.T. Curtis, S.P. Norton, R. Parker, R.A. Wilson, Atlas of Finite Groups. Clarendon Press, Oxford, 1985.
As a complement to my lecture notes, I strongly recommend Peter Webb's book, whose pre-print version is available at his webpage.

Oral Exam


In principle one should be able to explain the content of the lecture.
  • Definitions, statements of the theorems/propositions/lemmata should be known.
  • You should be able to explain short proofs as well as the main arguments of the longer proofs.
  • The Exercises mentioned in the lecture are important for the understanding of the theory.
  • There won't be any direct questions on the content of the Appendices.
  • You should also be able to give concrete examples/counter-examples to illustrate the results.
  • There will also be questions on concrete examples.
  • Also be ready to write down formally the concepts and results you are explaining.

A typical exam question would be as follows: Explain all entries in the character table on the page picture and find the missing entries. (Several methods are possible!)



Contents of the Lecture


Part I: Ordinary Representation Theory
  • Linear representations and characters
  • Modules over the group algebra
  • Character tables, orthogonality relations
  • Burnside's \(p^aq^b\)-theorem
  • Restriction, induction, inflation, tensor products
  • Clifford theory
  • Frobenius groups
Part II: TBA

Prerequisites: elementary group theory and linear algebra


Workload


Lecture : 4 SWS, i.e. 56 contact hours
Exercises : 2 SWS, i.e. 28 contact hours


Further Documents