Primitive Normal Bases for Towers of Field Extensions

Given an extension E/F of Galois fields and an intermediate field K, we consider the problem whether the (E, K)-trace of a primitive F-normal element of E can be a prescribed F-normal element of K. An interesting application is the existence of trace-compatible sequences of primitive F-normal elements for certain towers of Galois fields. In this respect, particular emphasis is laid on extensions having prime power degree.