S-structures on Lie algebras, introduced by Vinberg, represent a broad generalization of the notion of gradings by abelian groups. Gradings by, not necessarily reduced, root systems provide many examples of natural S-structures. Here we deal with a situation not covered by these gradings: the short (SL2 x SL2)-structures, where the reductive group is the simplest semisimple but not simple reductive group. The algebraic objects that coordinatize these structures are the J-ternary algebras of Allison, endowed with a nontrivial idempotent.
机构:
Belgorod State Univ, Dept Math & Informat Technol, Belgorod 308015, RussiaBelgorod State Univ, Dept Math & Informat Technol, Belgorod 308015, Russia
机构:
Chongqing Normal Univ, Sch Math & Comp Sci, Operat Res Lab, Chongqing 400047, Peoples R ChinaChongqing Normal Univ, Sch Math & Comp Sci, Operat Res Lab, Chongqing 400047, Peoples R China