Group of prime power order: Difference between revisions

From Groupprops
No edit summary
 
(4 intermediate revisions by 2 users not shown)
Line 1: Line 1:
[[importance rank::2| ]]
{{prime-parametrized group property}}
{{prime-parametrized group property}}
{{finite group property}}
{{finite group property}}


==Definition==
==Definition==


A '''group of prime power order''' is defined as a [[finite group]] whose order is a power of a prime.
===Symbol-free definition===
A '''group of prime power order''' is defined in the following equivalent ways:
 
* It is a [[finite group]] whose order is a power of a prime.
* It is a [[finite group]] that is also a [[p-group]] for some prime <math>p</math>: the [[order of an element|order]] of every element is a power of that same prime <math>p</math>
 
===Equivalence of definitions===
{{proofat|[[Equivalence of definitions of group of prime power order]]}}


==Relation with other properties==
==Relation with other properties==
Line 15: Line 22:
* [[Group whose order has at most two prime factors]]
* [[Group whose order has at most two prime factors]]


==Distribution of orders==
==Specific information==
 
===Groups of prime order===
 
For every prime <math>p</math>, there is only one group of order <math>p</math>, viz the cyclic group of <math>p</math> elements.
 
===Groups of prime-squared order===
 
Any group whose order is the square of a prime must be Abelian. {{proofat|[[Prime squared is Abelianness-forcing]]}}
 
Hence there are two possibilities for such a group: the cyclic group of order <math>p^2</math> and the [[elementary Abelian group]] of order <math>p^2</math>.
 
===Groups of prime-cubed order===
 
For the order a cube of a prime, there are three Abelian possibilities (corresponding to the three possible unordered partitions of 3). There are two non-Abelian possibilities, the [[group of prime-cubed order:U3p|group of unipotent matrices of order 3 over the prime field]] and the semidirect product of the cyclic group of order <math>p^2</math> by a cyclic group of order <math>p</math>.
 
===For higher orders===
 
{{further|[[enumeration of groups of prime power order]]}}
 
The number of groups of order <math>16 = 2^4</math> is 14. For an odd prime <math>p</math>, the number of groups of order <math>p^4</math> is 15.
 
For higher powers of the prime, the number of groups of prime power order depends on the prime (in general, the larger the prime, the greater the number of groups).
 
Higman and Sims have studied in detail the function:
 
<math>f(n,p)</math>


which measures the number of isomorphism classes of groups of order <math>p^n</math>.
See [[groups of prime power order]] for more specific information.

Latest revision as of 03:35, 17 December 2011

The article defines a property of groups, where the definition may be in terms of a particular prime that serves as parameter
View other prime-parametrized group properties | View other group properties

This article defines a property that can be evaluated for finite groups (and hence, a particular kind of group property)
View other properties of finite groups OR View all group properties

Definition

Symbol-free definition

A group of prime power order is defined in the following equivalent ways:

Equivalence of definitions

For full proof, refer: Equivalence of definitions of group of prime power order

Relation with other properties

Weaker properties

Specific information

See groups of prime power order for more specific information.