A more general framework for coGalois theory

Abstract

The paper is an extended version of a talk given at the International Conference: Experimental and Theoretical Methods in Algebra, Geometry and Topology, which took place June 21--24, 2013 in Eforie Nord (Romania). Its purpose is to present a more general framework for a fairly new theory in Field Theory, called coGalois Theory, which is somewhat dual to the very classical Galois Theory and is more general than the Kummer Theory. The main object of investigation in this more general framework is the coGalois connexion naturally associated to any triple $\,(Γ, \frak{G}, η)\,$, where $\,Γ\,$ is a profinite group, $\,\frak{G}\,$ is a profinite operator $\,Γ$-group, and $\,η: Γ\longrightarrow \frak{G}\,$ is a continuous $\,1$-cocycle with the property that the profinite group $\,\frak{G}\,$ is topologically generated by the image $\,η(Γ)$.