International Journal of Mathematics and Mathematical Sciences
Volume 2003 (2003), Issue 68, Pages 4263-4323
doi:10.1155/S0161171203203458
Abstract
A correspondence between quartic étale algebras over a
field and quadratic étale extensions of cubic étale
algebras is set up and investigated. The basic
constructions are laid out in general
for sets with a profinite group action and for torsors,
and translated in terms of étale algebras and Galois
algebras. A parametrization of cyclic
quartic algebras is given.