Some structure theories of Leibniz triple systems

In this paper, we investigate the Leibniz triple system $T$ and its universal Leibniz envelope $U(T)$. The involutive automorphism of $U(T)$ determining $T$ is introduced, which gives a characterization of the $\Z_2$-grading of $U(T)$. We give the relationship between the solvable radical $R(T)$ of $T$ and $Rad(U(T))$, the solvable radical of $U(T)$. Further, Levi's theorem for Leibniz triple systems is obtained. Moreover, the relationship between the nilpotent radical of $T$ and that of $U(T)$ is studied. Finally, we introduce the notion of representations of a Leibniz triple system.