%0 Journal Article %T On the structure of maximal solvable extensions and of Levi extensions of nilpotent algebras %A Libor Snobl %J Physics %D 2010 %I arXiv %R 10.1088/1751-8113/43/50/505202 %X We establish an improved upper estimate on dimension of any solvable algebra s with its nilradical isomorphic to a given nilpotent Lie algebra n. Next we consider Levi decomposable algebras with a given nilradical n and investigate restrictions on possible Levi factors originating from the structure of characteristic ideals of n. We present a new perspective on Turkowski's classification of Levi decomposable algebras up to dimension 9. %U http://arxiv.org/abs/1003.4223v2