Non-existence and splitting theorems for normal integral bases
Cornelius Greither, Henri Johnston (2012)
Annales de l’institut Fourier
Similarity:
We establish new conditions that prevent the existence of (weak) normal integral bases in tame Galois extensions of number fields. This leads to the following result: under appropriate technical hypotheses, the existence of a normal integral basis in the upper layer of an abelian tower forces the tower to be split in a very strong sense.