Noetherian not implies finitely presented: Difference between revisions

From Groupprops
(Created page with '{{group property non-implication| stronger = Noetherian group| weaker = finitely presented group}} ==Statement== A Noetherian group (also called ''slender group'', and defi...')
 
 
Line 20: Line 20:
==Proof==
==Proof==


===Example of the Tarski monster===
===Example of the Tarski group===


{{further|[[Particular example::Tarski monster]], [[Tarski monster is not finitely presented]]}}
{{further|[[Particular example::Tarski group]], [[Tarski group is not finitely presented]]}}


For a sufficiently large [[prime number]] <math>p</math>, we can construct a [[Tarski monster]]: an infinite simple group in which the only proper nontrivial subgroups are cyclic of order <math>p</math>. Clearly, the group is Noetherian and in fact has [[subgroup rank of a group|subgroup rank]] <math>2</math>: the whole group needs two generators and every proper nontrivial subgroup needs <math>1</math> generator.
For a sufficiently large [[prime number]] <math>p</math>, we can construct a [[Tarski group]] (also called ''Tarski monster''): an infinite simple group in which the only proper nontrivial subgroups are cyclic of order <math>p</math>. Clearly, the group is Noetherian and in fact has [[subgroup rank of a group|subgroup rank]] <math>2</math>: the whole group needs two generators and every proper nontrivial subgroup needs <math>1</math> generator.


However, Tarski monsters are not finitely presented.
However, Tarski monsters are not finitely presented.

Latest revision as of 18:00, 27 May 2010

This article gives the statement and possibly, proof, of a non-implication relation between two group properties. That is, it states that every group satisfying the first group property (i.e., Noetherian group) need not satisfy the second group property (i.e., finitely presented group)
View a complete list of group property non-implications | View a complete list of group property implications
Get more facts about Noetherian group|Get more facts about finitely presented group

Statement

A Noetherian group (also called slender group, and defined as a group in which every subgroup is finitely generated) need not be a finitely presented group, i.e., it need not possess any finite presentation. In particular, it need not be a Group in which every subgroup is finitely presented (?).

Related facts

Similar facts

Opposite facts

Proof

Example of the Tarski group

Further information: Tarski group, Tarski group is not finitely presented

For a sufficiently large prime number , we can construct a Tarski group (also called Tarski monster): an infinite simple group in which the only proper nontrivial subgroups are cyclic of order . Clearly, the group is Noetherian and in fact has subgroup rank : the whole group needs two generators and every proper nontrivial subgroup needs generator.

However, Tarski monsters are not finitely presented.