1-isomorphic groups: Difference between revisions
(Created page with '{{wikilocal}} {{group eqrel}} ==Definition== Suppose <math>G_1</math> and <math>G_2</math> are groups. We say that <math>G_1</math> and <math>G_2</math> are '''1-isomorphic...') |
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==Definition== | ==Definition== | ||
Suppose <math>G_1</math> and <math>G_2</math> are [[group]]s. We say that <math>G_1</math> and <math>G_2</math> are '''1-isomorphic''' if there exists a [[1-isomorphism of groups|1-isomorphism]] between | Suppose <math>G_1</math> and <math>G_2</math> are [[group]]s. We say that <math>G_1</math> and <math>G_2</math> are '''1-isomorphic''' if there exists a [[1-isomorphism of groups|1-isomorphism]] between <math>G_1</math> and <math>G_2</math>, i.e., a [[1-homomorphism of groups]] from <math>G_1</math> to <math>G_2</math> whose inverse is also a 1-homomorphism. In other words, there is a bijection between <math>G_1</math> and <math>G_2</math> whose restriction to any cyclic subgroup on either side is an isomorphism to its image. | ||
== | ===Historical term=== | ||
=== | G. A. Miller used the term ''conformal groups'' to describe what are referred to here are 1-isomorphic groups. However, the term "conformal group" has a different, much more famous meaning as the group of angle-preserving symmetries of a geometric space. | ||
==Finite version== | |||
Two finite groups that are 1-isomorphic are termed [[1-isomorphic finite groups]]. There are many equivalent characterizations of 1-isomorphic finite groups. | |||
==Facts== | |||
Any [[Lazard Lie group]] is 1-isomorphic to the additive group of its Lazard Lie ring. This shows that many [[group of prime power order|groups of small prime power order]] are 1-isomorphic to [[abelian group of prime power order|abelian groups]]. {{further|[[Lazard Lie group is 1-isomorphic to the additive group of its Lazard Lie ring]]}} | Any [[Lazard Lie group]] is 1-isomorphic to the additive group of its Lazard Lie ring. This shows that many [[group of prime power order|groups of small prime power order]] are 1-isomorphic to [[abelian group of prime power order|abelian groups]]. {{further|[[Lazard Lie group is 1-isomorphic to the additive group of its Lazard Lie ring]]}} | ||
==Relation with other relations== | |||
===Stronger relations=== | |||
{| class="sortable" border="1" | |||
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions | |||
|- | |||
| [[Weaker than::isomorphic groups]] || || || || {{intermediate notions short|1-isomorphic groups|isomorphic groups}} | |||
|} | |||
===Weaker relations=== | |||
{| class="sortable" border="1" | |||
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions | |||
|- | |||
| [[Stronger than::directed power graph-equivalent groups]] || || || || {{intermediate notions short|directed power graph-equivalent groups|1-isomorphic groups}} | |||
|- | |||
| [[Stronger than::undirected power graph-equivalent groups]] || || || || {{intermediate notions short|undirected power graph-equivalent groups|1-isomorphic groups}} | |||
|} | |||
See also [[1-isomorphic finite groups#Weaker properties]]. | |||
Latest revision as of 19:38, 24 June 2013
BEWARE! This term is nonstandard and is being used locally within the wiki. [SHOW MORE]
This article defines an equivalence relation over the collection of groups. View a complete list of equivalence relations on groups.
Definition
Suppose and are groups. We say that and are 1-isomorphic if there exists a 1-isomorphism between and , i.e., a 1-homomorphism of groups from to whose inverse is also a 1-homomorphism. In other words, there is a bijection between and whose restriction to any cyclic subgroup on either side is an isomorphism to its image.
Historical term
G. A. Miller used the term conformal groups to describe what are referred to here are 1-isomorphic groups. However, the term "conformal group" has a different, much more famous meaning as the group of angle-preserving symmetries of a geometric space.
Finite version
Two finite groups that are 1-isomorphic are termed 1-isomorphic finite groups. There are many equivalent characterizations of 1-isomorphic finite groups.
Facts
Any Lazard Lie group is 1-isomorphic to the additive group of its Lazard Lie ring. This shows that many groups of small prime power order are 1-isomorphic to abelian groups. Further information: Lazard Lie group is 1-isomorphic to the additive group of its Lazard Lie ring
Relation with other relations
Stronger relations
| Property | Meaning | Proof of implication | Proof of strictness (reverse implication failure) | Intermediate notions |
|---|---|---|---|---|
| isomorphic groups | |FULL LIST, MORE INFO |
Weaker relations
| Property | Meaning | Proof of implication | Proof of strictness (reverse implication failure) | Intermediate notions |
|---|---|---|---|---|
| directed power graph-equivalent groups | |FULL LIST, MORE INFO | |||
| undirected power graph-equivalent groups | |FULL LIST, MORE INFO |