Lie Groups and Lie Algebra
Video Lectures
Displaying all 32 video lectures.
Lecture 1![]() Play Video |
Lec 1A - Introduction to Lie Groups |
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Lec 1B - Lie Groups Definitions and Basic Properties |
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Lec 2A - Invariant Vector Fields & The Exponential Map |
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Lec 2B - The Lie Algebra of a Lie Group |
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Lec 3A - The Lie Algebra of a Lie Group II |
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Lec 3B - Commuting Elements & Component of the Identity |
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Lec 4A - Commutative Lie Groups |
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Lec 4B - Lie Subgroups & Analytic Subgroup Theorem |
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Lec 5A - Closed Subgroups |
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Lec 5B - The Groups SU(2) and SO(3) |
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Lec 6A - Group Actions and Orbit Spaces |
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Lec 6B - Actions of Principal Fiber Bundle Type & Smoothness Principle |
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Lec 7A - Proper and Free Actions & Coset Spaces Section 12: existence of Thm 12.5; principal fiber bundles Section 13: proper and free actions Section 14: coset spaces skipped Section 15: orbits of smooth actions. Section 16: the Baire property: background reading Section 17: normal subgroups, the isomorphism theorem |
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Lec 7B - Baire Property, Normal Subgroups, and Isomorphism Theorem Section 12: existence of Thm 12.5; principal fiber bundles Section 13: proper and free actions Section 14: coset spaces skipped Section 15: orbits of smooth actions. Section 16: the Baire property: background reading Section 17: normal subgroups, the isomorphism theorem |
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Lec 8A - Densities and Integration A few comments on Section 15: orbits of smooth actions. Prepare by reading this section in advance. Section 18: skipped Section 19: Densities and integration |
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Lec 8B - Densities and Integration II A few comments on Section 15: orbits of smooth actions. Prepare by reading this section in advance. Section 18: skipped Section 19: Densities and integration |
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Lec 9A - left Haar measure, bi-invariant Haar measure Section 19: left Haar measure, bi-invariant Haar measure Section 20: finite dimensional continuous representations: basic notions: invariant subspace, intertwining operator, equivalence, irreducibility, unitary representation, unitarizability |
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Lec 9B - Finite Dimensional Continuous Representations Section 19: left Haar measure, bi-invariant Haar measure Section 20: finite dimensional continuous representations: basic notions: invariant subspace, intertwining operator, equivalence, irreducibility, unitary representation, unitarizability |
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Lec 10A - Schur's Lemma & Orthogonality Section 20: Schur's lemma, example: irreducible representations for SU(2) Section 21: Schur orthogonality: for matrix coefficients, done in class. Section 23: Formulation of the Peter-Weyl theorem. Sections 24 and 25: proof of Peter-Weyl not done in class. Read on your own! |
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Lec 10B - Formulation of the Peter-Weyl theorem Section 20: Schur's lemma, example: irreducible representations for SU(2) Section 21: Schur orthogonality: for matrix coefficients, done in class. Section 23: Formulation of the Peter-Weyl theorem. Sections 24 and 25: proof of Peter-Weyl not done in class. Read on your own! |
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Lec 11A - Characters and Multiplicities Corollary 21.5 and equivariant form of Peter-Weyl theorem Section 22: characters and multiplicities Sections 26, 27: class functions and classical Fourier series. Read by yourself: Section 28: 28.1, 28.2, 28.3, 28.4, 28.6: classification of the irreducible representations of SU(2) |
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Lec 11B - Class Functions and Classical Fourier Series Corollary 21.5 and equivariant form of Peter-Weyl theorem Section 22: characters and multiplicities Sections 26, 27: class functions and classical Fourier series. Read by yourself: Section 28: 28.1, 28.2, 28.3, 28.4, 28.6: classification of the irreducible representations of SU(2) |
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Lec 12A - Lie Algebra Representations Section 29: Lie algebra representations Section 30: irreducible representations of sl(2,C) Section 31: roots and weights |
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Lec 12B - Irreducible Representations of sl(2,C) Section 29: Lie algebra representations Section 30: irreducible representations of sl(2,C) Section 31: roots and weights |
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Lec 13A - Highest Weight of Irreducible Representation Section 31: highest weight of irreducible representation Section 32, just result Section 35, compact Lie algebras: decomposition into simple ideals. |
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Lec 13B - Compact Lie Algebras Section 31: highest weight of irreducible representation Section 32, just result Section 35, compact Lie algebras: decomposition into simple ideals. |
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Lec 14A - Automorphisms and Derivations Section 33, automorphisms and derivations (study yourselves). Section 34, characterization of compact semisimple Lie algebras by Killing form. Section 36: root systems for compact algebras; up to Proposition 36.6. Read the proof of Prop. 36.6 by yourself. |
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Lec 14B - Characterization of Compact Semisimple Lie Algebras by Killing form Section 33, automorphisms and derivations (study yourselves). Section 34, characterization of compact semisimple Lie algebras by Killing form. Section 36: root systems for compact algebras; up to Proposition 36.6. Read the proof of Prop. 36.6 by yourself. |
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Lec 15A - Reflections and the Weyl group Section 36: additional properties of root systems: reflections and the Weyl group. Section 37: classification of irreducible representations by highest weight and Weyl's formulas. In the lecture notes, only the results are discussed. Read this on your own. Section 38.1, up to Lemma 38.4. |
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Lec 15B - Classification of Irreducible Representations Section 36: additional properties of root systems: reflections and the Weyl group. Section 37: classification of irreducible representations by highest weight and Weyl's formulas. In the lecture notes, only the results are discussed. Read this on your own. Section 38.1, up to Lemma 38.4. |
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Lec 16A - Cartan Integers (Final lecture) Section 38.1 from Lemma 38.4: Cartan integers. 38.2: positive and fundamental systems 38.3: the rank two root systems 38.5: Dynkin diagrams The classification of root systems, hence of compact semisimple algebras. |
Lecture 32![]() Play Video |
Lec 16B - Dynkin Diagrams & Classification of Root Systems (Final Lecture) Section 38.1 from Lemma 38.4: Cartan integers. 38.2: positive and fundamental systems 38.3: the rank two root systems 38.5: Dynkin diagrams. The classification of root systems, hence of compact semisimple algebras. |