Fine gradings on simple classical Lie algebras
arXiv:0906.0655
Abstract
The fine abelian group gradings on the simple classical Lie algebras (including D4) over algebraically closed fields of characteristic 0 are determined up to equivalence. This is achieved by assigning certain invariant to such gradings that involve central graded division algebras and suitable sesquilinear forms on free modules over them.
40 pages. A few arguments have been expanded and some misprints corrected