Vektoren minimaler Länge in Gittern mit einem Automorphismus.
Let be an algebraic unit of the degree . Assume that the extension is Galois. We would like to determine when the order of is -invariant, i.e. when the complex conjugates of are in , which amounts to asking that , i.e., that these two orders of have the same discriminant. This problem has been solved only for by using an explicit formula for the discriminant of the order . However, there is no known similar formula for . In the present paper, we put forward and motivate three...