arXiv subjects
Publications and source records attributed to Karen Acquista.
We give a criterion for the cohomological dimension of a field, involving norm maps on Milnor K-theory; this criterion was originally formulated by Kato. The theorem we prove is a generalization of a theorem in Serre's book on Galois cohomology.
In the setting of generalized class field theory, one has a field K with a hyper-class formation C, a complex of G_K-modules that plays the role of a class formation. Letting C(L) denote H^0(G_L, C), there is a distinguished cohomology class in H^2(Gal(L/K), C(L)), the hyper-fundamental class. In this paper, we prove that a group extension of Gal(L/K) by C(L) whose corresponding cohomology class is the hyper-fundamental class satisfies the classical axioms of a Weil group.