摘要
Let g be a complex simple Lie algebra.We consider subalgebras m which are Levi factors of parabolic subalgebras of g, or equivalently m is the centralizer of its center. We introduced the notion of admissible systems on finite order g-automorphisms θ, and show that θ has admissible systems if and only if its fixed point set is a Levi factor.We then use the extended Dynkin diagrams to characterize such automorphisms, and look for automorphisms of minimal order.