Quotient-subisomorph-containing 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]
Definition
The following are some equivalent definitions of quotient-subisomorph-containing subgroup.
No. | Shorthand | A subgroup of a group is termed a quasiverbal subgroup if ... |
---|---|---|
1 | contained in the kernel of any homomorphism to the quotient | for any homomorphism of groups , is contained in the kernel of . |
2 | intersection of normal subgroups whose quotients satisfy a subgroup-closed group property | there exists a subgroup-closed group property such that is the intersection of all normal subgroups of for which the quotient group satisfies property . |
3 | smallest normal subgroup whose quotient satisfies a subgroup-closed group property | there exists a subgroup-closed group property such that is the unique smallest normal subgroup of for which the quotient group satisfies . Note that every that works for the preceding definition need not work for this definition. |
Relation with other properties
Stronger properties
Property | Meaning | Proof of implication | Proof of strictness (reverse implication failure) | Intermediate notions |
---|---|---|---|---|
verbal subgroup | union of the images of word maps | |FULL LIST, MORE INFO | ||
pseudoverbal subgroup | intersection of normal subgroups with quotients in a pseudovariety | |FULL LIST, MORE INFO | ||
quasiverbal subgroup | intersection of normal subgroups with quotients in a quasivariety | |FULL LIST, MORE INFO | ||
normal subgroup having no nontrivial homomorphism to its quotient group | no nontrivial homomorphism from the subgroup to the quotient group | |FULL LIST, MORE INFO | ||
normal Sylow subgroup | normal and a Sylow subgroup | |FULL LIST, MORE INFO | ||
Normal Hall subgroup | normal and a Hall subgroup | quotient-subisomorph-containing subgroup|normal Hall subgroup}} |
Weaker properties
- Weakly image-closed fully invariant subgroup
- Fully invariant subgroup
- Strictly characteristic subgroup
- Characteristic subgroup