Lecture Description
Section 31: highest weight of irreducible representation
Section 32, just result
Section 35, compact Lie algebras: decomposition into simple ideals.
Course Index
- Lec 1A - Introduction to Lie Groups
- Lec 1B - Lie Groups Definitions and Basic Properties
- Lec 2A - Invariant Vector Fields & The Exponential Map
- Lec 2B - The Lie Algebra of a Lie Group
- Lec 3A - The Lie Algebra of a Lie Group II
- Lec 3B - Commuting Elements & Component of the Identity
- Lec 4A - Commutative Lie Groups
- Lec 4B - Lie Subgroups & Analytic Subgroup Theorem
- Lec 5A - Closed Subgroups
- Lec 5B - The Groups SU(2) and SO(3)
- Lec 6A - Group Actions and Orbit Spaces
- Lec 6B - Actions of Principal Fiber Bundle Type & Smoothness Principle
- Lec 7A - Proper and Free Actions & Coset Spaces
- Lec 7B - Baire Property, Normal Subgroups, and Isomorphism Theorem
- Lec 8A - Densities and Integration
- Lec 8B - Densities and Integration II
- Lec 9A - left Haar measure, bi-invariant Haar measure
- Lec 9B - Finite Dimensional Continuous Representations
- Lec 10A - Schur's Lemma & Orthogonality
- Lec 10B - Formulation of the Peter-Weyl theorem
- Lec 11A - Characters and Multiplicities
- Lec 11B - Class Functions and Classical Fourier Series
- Lec 12A - Lie Algebra Representations
- Lec 12B - Irreducible Representations of sl(2,C)
- Lec 13A - Highest Weight of Irreducible Representation
- Lec 13B - Compact Lie Algebras
- Lec 14A - Automorphisms and Derivations
- Lec 14B - Characterization of Compact Semisimple Lie Algebras by Killing form
- Lec 15A - Reflections and the Weyl group
- Lec 15B - Classification of Irreducible Representations
- Lec 16A - Cartan Integers
- Lec 16B - Dynkin Diagrams & Classification of Root Systems
Course Description
In this course we will begin by studying the basic properties of Lie groups. Much of the structure of a connected Lie group is captured by its Lie algebra, which may be defined as the algebra of left invariant vector fields. The exponential map will be introduced, and the relation between the structure of a Lie group and its Lie algebra will be investigated. Actions of Lie groups will be studied.
After this introduction we will focus on compact Lie groups and the integration theory on them. The groups SU(2) and SO(3) will be discussed as basic examples. We will study representation theory and its role in the harmonic analysis on a Lie group. The classification of the irreducible representations of SU(2) will be studied.
The final part of the course will be devoted to the classification of compact Lie algebras. Key words are: root system, finite reflection group, Cartan matrix, Dynkin diagram. The course will be concluded with the formulation of the classification of irreducible representations by their highest weight and with the formulation of Weyl's character formula.
A Lie group is a group with the additional structure of a differentiable manifold for which the group operation is differentiable. The name Lie group comes from the Norwegian mathematician M. Sophus Lie (1842-1899) who was the first to study these groups systematically in the context of symmetries of partial differential equations.
The theory of Lie groups has developed vastly in the course of the previous century. It plays a vital role in the description of symmetries in Physics (quantum physics, elementary particles), Geometry and Topology, and Number Theory (automorphic forms).