AUTOMORPHISMS OF UNIFORM LATTICES OF NILPOTENT LIE GROUPS UP TO DIMENSION FOUR

摘要

In this paper, when G is a connected and simply connected nilpotent Lie group of dimension less than or equal to four, we study the uniform lattices Gamma of G up to isomorphism and then we study the structure of the automorphism group Aut(Gamma) of Gamma from the viewpoint of splitting as a natural extension.