Xd. Leng et J. Patera, GRADED CONTRACTIONS OF REPRESENTATIONS OF ORTHOGONAL AND SYMPLECTIC LIE-ALGEBRAS WITH RESPECT TO THEIR MAXIMAL PARABOLIC SUBALGEBRAS, Journal of physics. A, mathematical and general, 28(13), 1995, pp. 3785-3807
Parabolic gradings of the classical simple Lie algebras o(N,C), (N gre
ater than or equal to 5) and sp(2n, C), (n greater than or equal to 2)
with complex parameters are described for all maximal parabolic subal
gebras. All contractions which leave a maximal parabolic subalgebra in
tact and which preserve a parabolic grading (parabolic contractions of
Lie algebras) are found. Contractions of the irreducible representati
ons for each parabolic contraction of the Lie algebra are the main res
ults of the article.