Conjugate-commensurable subgroup
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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 | subgroup of finite index in its normal closure | |||
isomorph-commensurable subgroup | commensurable with every isomorphic subgroup | |||
automorph-commensurable subgroup | commensurable with every automorphic subgroup |