Minimum size of generating set: Difference between revisions
(Created page with '{{arithmetic function on groups}} ==Definition== Let <math>G</math> be a finitely generated group. The '''minimum size of generating set''' for <math>G</math>, often called…') |
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==Definition== | ==Definition== | ||
Let <math>G</math> be a [[ | Let <math>G</math> be a [[group]]. The '''minimum size of generating set''' for <math>G</math>, often called the '''rank''' or '''generating set-rank''' of <math>G</math>, and sometimes denoted <math>d(G)</math> or <math>r(G)</math>, is defined as the minimum possible size of a [[defining ingredient::generating set of a group|generating set]] for <math>G</math>. | ||
This number is finite if and only if the group is a [[finitely generated group]]. | |||
==Related notions== | ==Related notions== | ||
Revision as of 20:27, 31 July 2009
This article defines an arithmetic function on groups
View other such arithmetic functions
Definition
Let be a group. The minimum size of generating set for , often called the rank or generating set-rank of , and sometimes denoted or , is defined as the minimum possible size of a generating set for .
This number is finite if and only if the group is a finitely generated group.
Related notions
- Subgroup rank of a group: This is the maximum of the generating set-ranks over all subgroups of the group.
- Rank of a p-group: For a group of prime power order, this is the maximum of the ranks of all the abelian subgroups of the group.