HOW WELL DEVELOPED IS THE DYNAMO THEORY OF FLAT OBJECTS

The existing models of disk dynamos are reviewed and an attempt is made to assess the reliability of their predictions. We analyze key questions such as whether the infinitely extended layer is a proper approximation of the finite disk, or whether it overlooks the possibility of “forgotten modes”, i.e. whether there is a guarantee that, when the model is used in applications, the mode it predicts as the most easily excited is truly such.What we find is that all existing models of disk dynamos have shortcomings in these respects, so that the analysis of improved models is worth the effort. © 1990, Taylor & Francis Group, LLC. All rights reserved.