Orbits of automorphism groups of fields

dc.creatorKedlaya, Kiran S.
dc.creatorPoonen, Bjorn
dc.date2004-07-27
dc.date2005-06-28
dc.date.accessioned2026-07-07T05:10:45Z
dc.date.available2026-07-07T05:10:45Z
dc.descriptionWe address several specific aspects of the following general question: can a field K have so many automorphisms that the action of the automorphism group on the elements of K has relatively few orbits? We prove that any field which has only finitely many orbits under its automorphism group is finite. We extend the techniques of that proof to approach a broader conjecture, which asks whether the automorphism group of one field over a subfield can have only finitely many orbits on the complement of the subfield. Finally, we apply similar methods to analyze the field of Mal'cev-Neumann "generalized power series" over a base field; these form near-counterexamples to our conjecture when the base field has characteristic zero, but often fall surprisingly far short in positive characteristic.
dc.description15 pages; v2: refereed version
dc.identifierhttps://arxiv.org/abs/math/0407473
dc.identifierhttp://arxiv.org/abs/math/0407473
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/72028
dc.subjectCommutative Algebra
dc.subjectNumber Theory
dc.subject12F10 (Primary) 12J25 (Secondary)
dc.titleOrbits of automorphism groups of fields
dc.typetext

Files

Collections