Lie Algebras

Course Aim

Students wanting to learn graduate-level algebra, and especially representation theory. A solid grasp of linear algebra will be assumed, as well as an ability to understand and construct quite sophisticated mathematical proofs.

Course Description

Learn the fundamental objects in algebra, especially representation theory, with hands-on experience in computing representations and constructing sophisticated proofs for some powerful (and quite beautiful!) results. Practice focuses on the basic structures of simple Lie algebras over the complex numbers, as well as the theory of highest weight representation including Verma modules and enveloping algebras, concluding with Weyl's character formula for finite-dimensional simple modules. Additional topics include root systems, Cartan subalgebras, Cartan/triangular decomposition, Dynkin diagrams, and the Killing form.   

This is an alternating years course.

Course Contents

1) Definition and key examples of Lie algebras
2) Structure theory of Lie algebras
3) Root systems, Dynkin diagrams, and Weyl groups
4) Classification of finite-dimensional (semi-)simple Lie algebras
5) Highest weight modules, simple modules, and Verma modules
6) Weyl's character formula for finite-dimensional simple modules

Assessment

Homework: 100%. There will be roughly 6 sets of homework problems during the term.

Prerequisites or Prior Knowledge

Solid undergraduate linear algebra. Confident in following and constructing proofs. Some prior knowledge of the representation theory of finite groups is helpful but not completely necessary. Discuss this carefully with your academic mentor.

Textbooks

Introduction to Lie Algebras and Representation Theory, by James Humphreys

Reference Books

Representation Theory: A first course, by William Fulton and Joe Harris
Introduction to Lie algebras, by Karin Erdmann and Mark Wildon

Notes

Alternate years course: AY2024

Research Specialties