Some Factorizations in Universal Enveloping Algebras of Three Dimensional Lie Algebras and Generalizations

摘要

We introduce the notion of Lie algebras with plus-minus pairs as wellas regular plus-minus pairs. These notions deal with certain factorizationsin universal enveloping algebras. We show that many important Lie algebrashave such pairs and we classify, and give a full treatment of, the threedimensional Lie algebras with plus-minus pairs.