The representation theory of groups investigates the different ways in which a given group acts on vector spaces.
In this lecture, we first explain the classification theory of the (finite-dimensional) irreducible representations of symmetric groups over the complex numbers, and then give an explicit realization of the irreducible representations.
For this purpose, rather than following the classical route by Frobenius, Schur, and Young, we take an elegant, novel approach devised by Okounkov-Vershik.
This course is followed by "Advanced topics in Algebra H1" in the fourth quarter.
Students are expected to:
- obtain basic notions and methods in the representation theory of symmetric groups,
- understand the classification theory of the irreducible representations of symmetric groups,
- understand how to construct explicitly irreducible representations of symmetric groups.
symmetric groups, irreducible representations, branching graph, Young graph
✔ Specialist skills | Intercultural skills | Communication skills | Critical thinking skills | Practical and/or problem-solving skills |
This is a standard lecture course. There will be some homework assignments.
Course schedule | Required learning | |
---|---|---|
Class 1 | Symmetric groups and their (finite-dimensional) irreducible representations | Details will be provided during each class session |
Class 2 | Gelfand-Zetlin algebras and the structure theorem | Details will be provided during each class session |
Class 3 | Branching graph and its properties: part 1 | Details will be provided during each class session |
Class 4 | Branching graph and its properties: part 2 | Details will be provided during each class session |
Class 5 | Young graph and its properties | Details will be provided during each class session |
Class 6 | hook length formula and its proof | Details will be provided during each class session |
Class 7 | Graph isomorphism theorem: part 1 | Details will be provided during each class session |
Class 8 | Graph isomorphism theorem: part 2 | Details will be provided during each class session |
To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.
None required.
T. Ceccherini-Silberstein, F. Scarabotti, F. Tolli, Representation Theory of the Symmetric Groups, Cambridge University Press, 2010.
M. Lorenz, A Tour of Representation Theory, American Mathematical Society, 2018.
Course scores are evaluated by homework assignments (100%). Details will be announced during the course.
Advanced linear algebra and basic undergraduate algebra
naito[at]math.titech.ac.jp