Conjugate-commensurable subgroup: Difference between revisions

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===Symbol-free definition===
===Symbol-free definition===


A subgroup of a group is termed '''conjugate-commensurable''' if it is [[defining ingredient::commensurable subgroups|commensurable]] with each of its [[defining ingredient::conjugate subgroups]].
A subgroup of a group is termed '''conjugate-commensurable''' if it is [[defining ingredient::commensurable subgroups|commensurable]] with each of its [[defining ingredient::conjugate subgroups]]. Equivalently, its [[defining ingredient::commensurator of a subgroup|commensurator]] in the whole group is the whole group.


===Definition with symbols===
===Definition with symbols===

Revision as of 21:00, 26 May 2010

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This article defines a subgroup property: a property that can be evaluated to true/false given a group and a subgroup thereof, invariant under subgroup equivalence. View a complete list of subgroup properties[SHOW MORE]

This is a variation of normal subgroup|Find other variations of normal subgroup | Read a survey article on varying normal subgroup

Definition

Symbol-free definition

A subgroup of a group is termed conjugate-commensurable if it is commensurable with each of its conjugate subgroups. Equivalently, its commensurator in the whole group is the whole group.

Definition with symbols

A subgroup of a group is termed a conjugate-commensurable subgroup if, for any , has finite index in both and .

Relation with other properties

Stronger properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
Normal subgroup |FULL LIST, MORE INFO
Subgroup of finite group
Finite subgroup
Subgroup of finite index |FULL LIST, MORE INFO
Nearly normal subgroup
Isomorph-commensurable subgroup commensurable with every isomorphic subgroup
Automorph-commensurable subgroup commensurable with every automorphic subgroup