Gelfand-Tsetlin bases for Lie groups over finite fields There is a method of constructing representations of classical Lie algebras via Gelfand-Tsetlin bases. It has also been applied to Symmetric groups by Vershik and Okounkov. Does anybody know of any application of the method to complex representations of $GL_n(\mathbb F_q)$? Or, at least, any results in this directions, like what is the centralizer of $GL_{n-1}$ in $\mathbb C[GL_n]$?
 A: My earlier comment was not at all well-focused.    After more thought, I'm inclined to be pessimistic about using a Gelfand-Tsetlin approach here (even if it has some success for symmetric groups).  Though of course it would be interesting to be proven wrong.    
As Matt Davis reminds me, my offhand reference to Schur-Weyl duality is not helpful here since the work of Benson, Doty, and others deals mainly with the representations of various groups over fields of prime characteristic.   (See especially Doty's papers on arXiv.)    Irreducible representations of finite general linear groups over $\mathbb{C}$ are very difficult to construct directly and have very little in common with the finite dimensional representations of general linear groups or their Lie algebras in characteristic 0.    Instead, the theory imitates more closely the infinite dimensional Harish-Chandra approach to Lie group representations in which parabolic induction is exploited together with a study of "discrete series".   
J.A. Green's 1955 TAMS paper followed somewhat this pattern in developing combinatorially the character theory of finite general linear groups.   But there is little insight here into constructing the elusive discrete series characters; instead orthogonality relations and the like are exploited.   The best approach to an actual construction of discrete series representations was given in Lusztig's 1974 Annals of Mathematics Studies No. 81.   Soon after that, Deligne and Lusztig pioneered a more sophisticated method for constructing generalized characters of arbitrary finite groups of Lie type.   This has become the dominant influence in the subject, since Lusztig's earlier techniques don't go far enough beyond the finite general linear case.
A: Not an answer either, but in response to Jim - Schur-Weyl duality doesn't always apply over finite fields. See http://www.ams.org/mathscinet-getitem?mr=2563588 for one result and some discussion of the related issues. 
