Lie algebras generated by Jordan operators
It is proved that if is a Jordan operator on a Hilbert space with the Jordan decomposition , where is normal and is compact and quasinilpotent, i = 1,2, and the Lie algebra generated by J₁,J₂ is an Engel Lie algebra, then the Banach algebra generated by J₁,J₂ is an Engel algebra. Some results for normal operators and Jordan operators on Banach spaces are given.