Obere und untere Schranken vollergodischer dynamischer Systeme mit quasidiskretem Spektrum

Abstract

For every class of dynamical systems the factor conception induces an order structure. With respect to this structure one can regard common factors and common multiples of any two dynamical systems. In the following this question is studied for the class $\mathcal{H}\ast$ of totally ergodic dynamical systems with quasidiscrete spectrum and conditions of existence and of uniqueness are considered for maximal lower and minimal upper bounds for any two systems of $\mathcal{H}\ast$.