Math 128, Spring 2014
Current problems in combinatorics:
Combinatorial representation theory of complex Lie algebras and related topics



Professor: Zajj Daugherty
Office hours: 314 Kemeny, by appointment or drop-in (see calendar below).
Class: MWF 1:45-2:50 in 028 Haldeman Center


Main file (last updated: 5/19)
TeX files for the notes: m128s14Notes.tex, preamble.tex
(Notes handed out on the first day)

Monday 3/24: Introduction, survey of the symmetric group
Wednesday 3/26: Lie algebras and their enveloping algebras
Friday 3/28: Representations and Hopf algebras
Monday 3/31: Representations of sl_2
Wednesday 4/2: Finishing sl_2, semisimple Lie algebras, forms
Friday 4/4: Jordan-Chevalley, Cartan subalgebras, weights, roots
Monday 4/7: Some facts about roots
Wednesday 4/9: More facts about roots
Monday 4/14: More on roots
Wednesday 4/16: A first look at root systems, reps of g
Thursday 4/17: Representations of g continued
Friday 4/18: Representations of g continued
Monday 4/21: Representations of g continued
Wednesday 4/30: Bases and Weyl groups
Friday 5/2: Weyl groups
Monday 5/5: More on representation theory
Wednesday 5/7: Weyl character formula
Friday 5/9: Littelmann path model and crystals
Monday 5/12: More on Littelmann path model and crystals
Wednesday 5/14: Centralizer algebras
Friday 5/16: Schur-Weyl duality
Monday 5/19: Idempotents and the Temperley-Lieb algebra
Wednesday 5/21: Diagram algebras
Thursday 5/22: Quantum groups
Friday 5/23: Braid groups and their quotients

Tex files for slides can be found by replacing .pdf with .tex for most of the files above. You'll also need the BeamerPreamble.


Complete a minimum of five of the following.

  1. Due Friday 4/4: Some things about the classical Lie algebras. (.pdf) (.tex) (answers)
  2. Due Wednesday 4/9: Some things about sl2. (.pdf) (.tex) (answers)
  3. Due Monday 4/14: Some things about NIBS forms. (.pdf) (.tex) (answers)
  4. Due Monday 4/21: Some things about roots. (.pdf) (.tex) (answers)
  5. Due Tuesday 4/29: Some things about mathematicians. [Credit given for CRT attendance] (.pdf) (.tex)
  6. Due Friday 5/2: Some things about weights and representations. (.pdf) (.tex) (answers)
  7. Due Friday 5/9: Some things about classification. (.pdf) (.tex) (answers)
  8. Due Monday 5/19: Some things about crystals. (.pdf) (.tex)
  9. Due Monday 6/2: Some things about centralizer algebras. (.pdf) (.tex)
  10. Due Monday 6/2: Some things about combinatorial representation theory. (.pdf) (.tex)

Preamble for homework tex files.


As people make appointments with me for general help, I will add them here so that others can also drop in.


Discrete Math Day at Dartmouth, April 12.
Conference on CRT at CRM, April 21-25.

Papers and books

[CP94] A guide to quantum groups (Introduction), V. Chari and A. Pressley, Cambridge University Press (1994).

[DRV1] Affine and degenerate affine BMW algebras: The center, Z. Daugherty, A. Ram, and R. Virk, Osaka J. Math., 51-1 (2014).

[DRV2] Affine and degenerate affine BMW algebras: actions on tensor space, Z. Daugherty, A. Ram, and R. Virk, Selecta Math., 19-2 (2013) 611--653.

[GP00] Characters of finite Coxeter groups and Iwahori-Hecke algebras, Sections 7.1--7.2, M. Geck, G. Pfeiffer, London Mathematical Society Monographs. New Series, 21. The Clarendon Press, Oxford University Press, New York, 2000.

[GW10] Symmetry, Representations, and Invariants, Sections 4.1--4.3, R. Goodman, N. Wallach, Graduate Texts in Mathematics, Springer, New York, 2010.

[HK02] Introduction to Quantum Groups and Crystal Bases, section 3, J. Hong and S-J. Kang, Graduate Studies in Mathematics, Vol 43, American Mathematical Society (2002).

[KR02] Representations of Graded Hecke algebras, C. Kriloff and A. Ram, Representation Theory (6) (2002), 31-69.

[Li95] Paths and root operators in representation theory, P. Littelmann, Ann. of Math. (2) 142 (1995), no. 3, 499--525.

[Na96] Young's orthogonal form for Brauer's centralizer algebra, M. Nazarov, Journal of Algebra 182 (3), 664-693.

[Ra06] Alcove Walks, Hecke Algebras, Spherical Functions, Crystals and Column Strict Tableaux, A. Ram, Pure Appl. Math. Q. 2 (2006), no. 4, part 2, 963--1013.