Lie Groups and Lie Algebra

Video Lectures

Displaying all 32 video lectures.
Lecture 1
Lec 1A - Introduction to Lie Groups
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Lec 1A - Introduction to Lie Groups
Lecture 2
Lec 1B - Lie Groups Definitions and Basic Properties
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Lec 1B - Lie Groups Definitions and Basic Properties
Lecture 3
Lec 2A - Invariant Vector Fields & The Exponential Map
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Lec 2A - Invariant Vector Fields & The Exponential Map
Lecture 4
Lec 2B - The Lie Algebra of a Lie Group
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Lec 2B - The Lie Algebra of a Lie Group
Lecture 5
Lec 3A - The Lie Algebra of a Lie Group II
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Lec 3A - The Lie Algebra of a Lie Group II
Lecture 6
Lec 3B - Commuting Elements & Component of the Identity
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Lec 3B - Commuting Elements & Component of the Identity
Lecture 7
Lec 4A - Commutative Lie Groups
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Lec 4A - Commutative Lie Groups
Lecture 8
Lec 4B - Lie Subgroups & Analytic Subgroup Theorem
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Lec 4B - Lie Subgroups & Analytic Subgroup Theorem
Lecture 9
Lec 5A - Closed Subgroups
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Lec 5A - Closed Subgroups
Lecture 10
Lec 5B - The Groups SU(2) and SO(3)
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Lec 5B - The Groups SU(2) and SO(3)
Lecture 11
Lec 6A - Group Actions and Orbit Spaces
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Lec 6A - Group Actions and Orbit Spaces
Lecture 12
Lec 6B - Actions of Principal Fiber Bundle Type & Smoothness Principle
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Lec 6B - Actions of Principal Fiber Bundle Type & Smoothness Principle
Lecture 13
Lec 7A - Proper and Free Actions & Coset Spaces
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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
Lecture 14
Lec 7B - Baire Property, Normal Subgroups, and 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
Lecture 15
Lec 8A - Densities and Integration
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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
Lecture 16
Lec 8B - Densities and Integration II
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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
Lecture 17
Lec 9A - left Haar measure, bi-invariant Haar measure
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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
Lecture 18
Lec 9B - Finite Dimensional Continuous Representations
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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
Lecture 19
Lec 10A - Schur's Lemma & Orthogonality
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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!
Lecture 20
Lec 10B - Formulation of the Peter-Weyl theorem
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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!
Lecture 21
Lec 11A - Characters and Multiplicities
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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)
Lecture 22
Lec 11B - Class Functions and Classical Fourier Series
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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)
Lecture 23
Lec 12A - Lie Algebra Representations
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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
Lecture 24
Lec 12B - Irreducible Representations of sl(2,C)
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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
Lecture 25
Lec 13A - Highest Weight of Irreducible Representation
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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.
Lecture 26
Lec 13B - Compact Lie Algebras
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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.
Lecture 27
Lec 14A - Automorphisms and Derivations
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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.
Lecture 28
Lec 14B - Characterization of Compact Semisimple Lie Algebras by Killing form
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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.
Lecture 29
Lec 15A - Reflections and the Weyl group
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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.
Lecture 30
Lec 15B - Classification of Irreducible Representations
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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.
Lecture 31
Lec 16A - Cartan Integers
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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
Lec 16B - Dynkin Diagrams & Classification of Root Systems
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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.