LieAlgebra17

Lie Algebra - MTH430

August-November 2017

Instructor : Dr. Anupam Singh

Audience : UG, iPhD, and PhD

Schedule : Thursday 2-3 and Friday 10:50-11:50. Optional tutorial will be run by Dr. Uday Sharma and Dr. Dilpreet Kaur.

Evaluation : Test I - 20%

Mid-sem examination- 30%

Test II- 20%

End-sem examination- 30%

Prerequisite : Linear Algebra

Goal of the course : To understand Lie algebras and classification of simple Lie algebras---- This subject has wide application in Physics (for example, standard model SU(2)), Chemistry (for example, Crystallography), and forms backbone to the topics such as Number Theory, Algebraic Groups, Lie Groups, Differential Geometry, Dynamical Systems, Kac-Moody Lie algebras, Quantum Groups etc.

Proposed content : Lie algebra, solvable and nilpotent Lie algebras, simple and semisimple Lie algebras, Root systems and classification of simple Lie algebras.

Courses taught related to this topic in past: Linear Algebraic Groups (in 2015) and Classical Groups (in 2007)

References :

3 August 2017 Definition and example of gl(n)

4 August 2017 Examples gl(n), sl(n), t(n), n(n) etc

Recommended reading - Missed Opportunities by Freeman Dyson

Assignment I

10 August 2017 Story of Classification of Finite Simple Groups, example of classical Lie algebras, A_l, B_l, C_l, D_l

11 August 2017 Definitions: Ideals, homomorphism, Solvable Lie algebra, Simple Lie algebra etc.

17 August 2017 Solvable Lie algebra

18 August 2017 Tutorial

24 August 2017 Nilpotent Lie algebra, ad-nilpotent

25 August 2017 Holiday

31 August 2017 Engel's Theorem -Characterization of nilpotent Lie algebra

01 September 2017 Lie's theorem - Characterization of solvable Lie algebra

Assignment II - Test your linear algebra

02 September 2017 Test - I

07 September 2017 - Cartan's criteria, Killing form

08 September 2017 - classification of Semisimple Lie algebras vs. Killing form

Assignment III

14 September 2017 Semisimple Lie algebra as direct sum of simple Lie algebras

15 September 2017 Representations of sl(2)

20-27 September - Mid sem exam

5 October 2017 More on Representations of sl(2,C)

6 October 2017 Cartan decomposition of a semisimple Lie algebra

7 October 2017 (extra class - 2 hours) Associating root system to a semisimple Lie algebra

Assignment IV

12 October 2017 Associating a root system to a semisimple Lie algebra

13 October 2017 Associating a root system to a semisimple Lie algebra

19 October 2017 Holiday

20 October 2017 No class

26 October 2017 Tutorial - root systems of classical Lie algebras

27 October 2017 Tutorial - roots systems of classical Lie algebras

28 October 2017 Test - II

2 November 2017 Root system, classification of 2-dimensional root systems

3 November 2017 Classical root system, demo of rank 2 and 3 root systems

see Brian Hall - Instructions for building roots systems in Zometool: kit.pdf

9 November 2017 Weyl group of a root system, Base and positive roots, Coxeter graphs

10 November 2017 Dynkin diagrams, Classification of root systems

16 November 2017 Tutorial - Write down all classical roots systems, simple root system and compute Dynkin diagram and Weyl groups

17 November 2017 Tutorial

30 November 2017 End Semester Examination

What next?

  • Chevalley groups (Simple groups of Lie type : Carter)

  • Representation theory of semisimple Lie algebras, highest weight theory, Verma modules etc (Continue with Humphreys book)

  • Lie groups, compact Lie groups (Warner or Adams : Lie groups)

  • Algebraic groups (Humphreys)