Subisomorph-containing subgroup: Difference between revisions
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==Definition== | ==Definition== | ||
A [[subgroup]] <math>H</math> of a [[group]] <math>G</math> is termed '''subisomorph-containing''' if whenever <math>K</math> is a subgroup of <math> | A [[subgroup]] <math>H</math> of a [[group]] <math>G</math> is termed '''subisomorph-containing''' if whenever <math>K</math> is a subgroup of <math>H</math> and <math>L</math> is a subgroup of <math>G</math> such that <math>K</math> and <math>L</math> are [[isomorphic groups|isomorphic]], then <math>L</math> is also a subgroup of <math>H</math>. | ||
==Relation with other properties== | ==Relation with other properties== | ||
===In groups with specific properties=== | |||
* [[Finite group]] and [[periodic group]]: In a finite group and more generally in a [[periodic group]], the notion of subisomorph-containing subgroup coincides with the notions of [[subhomomorph-containing subgroup]] and [[variety-containing subgroup]]. {{further|[[Equivalence of definitions of variety-containing subgroup of finite group]], [[Equivalence of definitions of variety-containing subgroup of periodic group]]}} | |||
* [[Group of prime power order]]: For groups of prime power order, subisomorph-containing subgroups must be [[omega subgroups of group of prime power order]], though the converse, while true for [[regular p-group]]s, is not always true. {{proofat|[[Variety-containing implies omega subgroup in group of prime power order]], [[omega subgroups are variety-containing in regular p-group]], [[omega subgroups not are variety-containing]]}} | |||
===Stronger properties=== | ===Stronger properties=== | ||
{| class="sortable" border="1" | |||
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions | |||
|- | |||
| [[Weaker than::variety-containing subgroup]] || contains every subgroup of the whole group in the variety generated by it || || || {{intermediate notions short|subisomorph-containing subgroup|variety-containing subgroup}} | |||
|- | |||
| [[Weaker than::subhomomorph-containing subgroup]] || contains every subgroup of the whole group isomorphic to a subquotient of it || || || {{intermediate notions short|subisomorph-containing subgroup|subhomomorph-containing subgroup}} | |||
|- | |||
| [[Weaker than::normal Sylow subgroup]] || normal subgroup of prime power order whose order and index are relatively prime || || || {{intermediate notions short|subisomorph-containing subgroup|normal Sylow subgroup}} | |||
|- | |||
| [[Weaker than::normal Hall subgroup]] || subgroup whose order and index are relatively prime || || || {{intermediate notions short|subisomorph-containing subgroup|normal Hall subgroup}} | |||
|} | |||
===Weaker properties=== | ===Weaker properties=== | ||
{| class="sortable" border="1" | |||
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions | |||
|- | |||
| [[Stronger than::isomorph-containing subgroup]] || contains every isomorphic subgroup || || || {{intermediate notions short|isomorph-containing subgroup|subisomorph-containing subgroup}} | |||
|- | |||
| [[Stronger than::injective endomorphism-invariant subgroup]] || invariant under all injective endomorphisms || || || {{intermediate notions short|injective endomorphism-invariant subgroup|subisomorph-containing subgroup}} | |||
|- | |||
| [[Stronger than::intermediately injective endomorphism-invariant subgroup]] || injective endomorphism-invariant in every intermediate subgroup || || || {{intermediate notions short|intermediately injective endomorphism-invariant subgroup|subisomorph-containing subgroup}} | |||
|- | |||
| [[Stronger than::characteristic subgroup]] || invariant under every automorphism || || || {{intermediate notions short|characteristic subgroup|subisomorph-containing subgroup}} | |||
|- | |||
| [[Stronger than::intermediately characteristic subgroup]] || characteristic in every intermediate subgroup || || || {{intermediate notions short|intermediately characteristic subgroup|subisomorph-containing subgroup}} | |||
|- | |||
| [[Stronger than::transfer-closed characteristic subgroup]] || intersection with any subgroup is characteristic in that subgroup || || || {{intermediate notions short|transfer-closed characteristic subgroup|subisomorph-containing subgroup}} | |||
|} | |||
Latest revision as of 14:06, 1 June 2020
BEWARE! This term is nonstandard and is being used locally within the wiki. [SHOW MORE]
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]
If the ambient group is a finite group, this property is equivalent to the property: variety-containing subgroup
View other properties finitarily equivalent to variety-containing subgroup | View other variations of variety-containing subgroup |
Definition
A subgroup of a group is termed subisomorph-containing if whenever is a subgroup of and is a subgroup of such that and are isomorphic, then is also a subgroup of .
Relation with other properties
In groups with specific properties
- Finite group and periodic group: In a finite group and more generally in a periodic group, the notion of subisomorph-containing subgroup coincides with the notions of subhomomorph-containing subgroup and variety-containing subgroup. Further information: Equivalence of definitions of variety-containing subgroup of finite group, Equivalence of definitions of variety-containing subgroup of periodic group
- Group of prime power order: For groups of prime power order, subisomorph-containing subgroups must be omega subgroups of group of prime power order, though the converse, while true for regular p-groups, is not always true. For full proof, refer: Variety-containing implies omega subgroup in group of prime power order, omega subgroups are variety-containing in regular p-group, omega subgroups not are variety-containing
Stronger properties
| Property | Meaning | Proof of implication | Proof of strictness (reverse implication failure) | Intermediate notions |
|---|---|---|---|---|
| variety-containing subgroup | contains every subgroup of the whole group in the variety generated by it | |FULL LIST, MORE INFO | ||
| subhomomorph-containing subgroup | contains every subgroup of the whole group isomorphic to a subquotient of it | |FULL LIST, MORE INFO | ||
| normal Sylow subgroup | normal subgroup of prime power order whose order and index are relatively prime | |FULL LIST, MORE INFO | ||
| normal Hall subgroup | subgroup whose order and index are relatively prime | |FULL LIST, MORE INFO |
Weaker properties
| Property | Meaning | Proof of implication | Proof of strictness (reverse implication failure) | Intermediate notions |
|---|---|---|---|---|
| isomorph-containing subgroup | contains every isomorphic subgroup | |FULL LIST, MORE INFO | ||
| injective endomorphism-invariant subgroup | invariant under all injective endomorphisms | |FULL LIST, MORE INFO | ||
| intermediately injective endomorphism-invariant subgroup | injective endomorphism-invariant in every intermediate subgroup | |FULL LIST, MORE INFO | ||
| characteristic subgroup | invariant under every automorphism | |FULL LIST, MORE INFO | ||
| intermediately characteristic subgroup | characteristic in every intermediate subgroup | |FULL LIST, MORE INFO | ||
| transfer-closed characteristic subgroup | intersection with any subgroup is characteristic in that subgroup | |FULL LIST, MORE INFO |