Monomial group: Difference between revisions

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{{group property}}
{{group property}}
{{basicdef in|linear representation theory}}


==Definition==
==Definition==
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===Symbol-free definition===
===Symbol-free definition===


A [[group]] is termed '''monomial''' (or sometimes, a '''M-group''') if every [[irreducible representation]] of the group over the complex numbers is induced from a one-dimensional representation of a subgroup. Thus, any representation can, with a suitable choice of basis, be made into a representation with all the linear transformations being expressed by monomial matrices.
A [[finite group]] is termed '''monomial''' (or sometimes, a '''M-group''' or <math>M_1</math>-group) with respect to a field <math>k</math> (whose characteristic does not divide the group order) if it satisfies the following equivalent conditions:
 
# Every [[irreducible representation]] of the group over <math>k</math> is induced from a one-dimensional representation of a subgroup, i.e., a [[linear character]].
# Every finite-dimensional linear representation of the group over <math>k</math> is a [[defining ingredient::monomial linear representation]]: it is a direct sum of representations induced from one-dimensional representations of subgroups.


==Relation with other properties==
==Relation with other properties==
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===Stronger properties===
===Stronger properties===


* [[Finite nilpotent group]]
* [[Weaker than::Elementary group]]
* [[Finite supersolvable group]]
* [[Weaker than::Finite nilpotent group]]
* [[Weaker than::Finite supersolvable group]]: {{proofat|[[Finite supersolvable implies monomial]]}}


===Weaker properties===
===Weaker properties===


* [[Solvable group]]: This follows from the [[Taketa theorem]]
* [[Solvable group]]: This follows from the [[Taketa theorem]]

Latest revision as of 22:48, 10 November 2023

This article defines a group property: a property that can be evaluated to true/false for any given group, invariant under isomorphism
View a complete list of group properties
VIEW RELATED: Group property implications | Group property non-implications |Group metaproperty satisfactions | Group metaproperty dissatisfactions | Group property satisfactions | Group property dissatisfactions


This article gives a basic definition in the following area: linear representation theory
View other basic definitions in linear representation theory |View terms related to linear representation theory |View facts related to linear representation theory

Definition

Symbol-free definition

A finite group is termed monomial (or sometimes, a M-group or -group) with respect to a field (whose characteristic does not divide the group order) if it satisfies the following equivalent conditions:

  1. Every irreducible representation of the group over is induced from a one-dimensional representation of a subgroup, i.e., a linear character.
  2. Every finite-dimensional linear representation of the group over is a monomial linear representation: it is a direct sum of representations induced from one-dimensional representations of subgroups.

Relation with other properties

Stronger properties

Weaker properties