%0 Journal Article %T Factorizations in Universal Enveloping algebras of three dimensional Lie algebras and generalizations %A S. Berman %A J. Morita %A Y. Yoshii %J Mathematics %D 2001 %I arXiv %X We introduce the notion of Lie algebras with plus-minus pairs as well as regular plus-minus pairs. These notions deal with certain factorizations in universal enveloping algebras. We show that many important Lie algebras have such pairs and we classify, and give a full treatment of, the three dimensional Lie algebras with plus-minus pairs. %U http://arxiv.org/abs/math/0109139v1