Trivial group: Difference between revisions

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The '''trivial group''' is the group with only one element, which is its identity element.
The '''trivial group''' is the group with only one element, which is its identity element.
===Alternative definitions===
* The {{cyclic group}} on one element
* The {{symmetric group}} on one element
* The {{projective general linear group}} of order 1 over any field
* The {{special linear group}} of order 1 over any field


==Importance==
==Importance==

Revision as of 23:58, 23 September 2007

This article is about a particular group, i.e., a group unique upto isomorphism. View specific information (such as linear representation theory, subgroup structure) about this group
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Definition

The trivial group is the group with only one element, which is its identity element.

Alternative definitions

Importance

The trivial group is important in the following ways:

  • For any group, there is a unique homomorphism from the trivial group to that group, namely the homomorphism sending it to the identity element. Thus, the trivial group occurs in a unique way as a subgroup for any given group, namely the one-element subgroup comprising the identity element. This is termed the trivial subgroup.
  • For any group, there is a unique homomorphism to the trivial group from that group, namely the homomorphism sending everything to the identity element. Thus, the trivial group occurs in a unique way as a quotient group of any given group, namely its quotient by itself. This is termed the trivial quotient.