Induced Hopf Galois structures and their local Hopf Galois modules

The regular subgroup determining an induced Hopf Galois structure for a Galois extension L/K is obtained as direct product of the corresponding regular groups of the inducing subextensions. We describe here the attached Hopf algebra and Hopf action of an induced structure and we prove that they are...

Descripción completa

Detalles Bibliográficos
Autores: Gil Muñoz, Daniel, Río Doval, Ana|||0000-0003-4785-8760
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/366323
Acceso en línea:https://hdl.handle.net/2117/366323
https://dx.doi.org/10.5565/PUBLMAT6612204
Access Level:acceso abierto
Palabra clave:Algebraic number theory
Field theory (Physics)
Hopf Galois structure
Hopf Galois module theory
Associated order
Nombres, Teoria algebraica de
Teoria de camps (física)
Classificació AMS::11 Number theory::11R Algebraic number theory: global fields
Classificació AMS::12 Field theory and polynomials::12F Field extensions
Àrees temàtiques de la UPC::Matemàtiques i estadística::Àlgebra::Teoria de nombres
Àrees temàtiques de la UPC::Matemàtiques i estadística::Àlgebra::Teoria de cossos i polinomis
Descripción
Sumario:The regular subgroup determining an induced Hopf Galois structure for a Galois extension L/K is obtained as direct product of the corresponding regular groups of the inducing subextensions. We describe here the attached Hopf algebra and Hopf action of an induced structure and we prove that they are obtained by tensoring the corresponding inducing objects. We give a general matrix description of the Hopf action which is useful to compute bases of associated orders. In case of an induced Hopf Galois structures it allows us to decompose the associated order, assuming that inducing subextensions are arithmetically disjoint.