Fixed subgroups and computation of auto-fixed closures in free-abelian times free groups

The classical result by Dyer–Scott about fixed subgroups of finite order automor-phisms of Fnbeing free factors of Fn is no longer true inZm×Fn. Within this more generalcontext, we prove a relaxed version in the spirit of Bestvina–Handel Theorem: the rank of fixed subgroups of finite order automorph...

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Detalles Bibliográficos
Autores: Roy, Mallika|||0000-0002-9730-5980, Ventura Capell, Enric|||0000-0003-3519-4135
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:2117/184934
Acceso en línea:https://hdl.handle.net/2117/184934
https://dx.doi.org/10.1016/j.jpaa.2019.106210
Access Level:acceso abierto
Palabra clave:Free-abelian times free
Automorphism
Fixed subgroup
Periodic subgroup
Auto-fixed closure
Classificació AMS::20 Group theory and generalizations::20E Structure and classification of infinite or finite groups
Àrees temàtiques de la UPC::Matemàtiques i estadística
Descripción
Sumario:The classical result by Dyer–Scott about fixed subgroups of finite order automor-phisms of Fnbeing free factors of Fn is no longer true inZm×Fn. Within this more generalcontext, we prove a relaxed version in the spirit of Bestvina–Handel Theorem: the rank of fixed subgroups of finite order automorphisms is uniformly bounded in terms of m, n. We also studyperiodic points of endomorphisms of Zm×Fn, and give an algorithm to compute auto-fixed closures of finitely generated subgroups of Zm×Fn. On the way, we prove the analog of Day’sTheorem for real elements in Zm×Fn, contributing a modest step into the project of doing sofor any right angled Artin group (as McCool did with respect to Whitehead’s Theorem in the free context).