Degree of a linear representation: Difference between revisions
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==Definition== | ==Definition== | ||
===Symbol-free definition=== | |||
The degree of a linear representation is defined as the dimension of the vector space to which the representation's map is defined. | The degree of a linear representation is defined as the dimension of the vector space to which the representation's map is defined. | ||
It also equals the value of the [[defining ingredient::character of a linear representation|character]] at the identity element. | |||
===Definition with symbols=== | |||
Suppose <math>(V,\rho)</math> is a linear representation of a group <math>G</math> over a field <math>k</math>, i.e. we have a homomorphism <math>\rho:G \to GL(V)</math>, where <math>V</math> is a vector space over <math>k</math>. Then, the degree of the representation <math>(V,\rho)</math> is defined as the dimension of <math>V</math> as a <math>k</math>-vector space. | |||
For a finite group, the degrees of irreducible representations are important numbers. {{further|[[degrees of irreducible representations]]}} | |||
Latest revision as of 16:16, 22 June 2008
This article gives a basic definition in the following area: linear representation theory
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Definition
Symbol-free definition
The degree of a linear representation is defined as the dimension of the vector space to which the representation's map is defined.
It also equals the value of the character at the identity element.
Definition with symbols
Suppose is a linear representation of a group over a field , i.e. we have a homomorphism , where is a vector space over . Then, the degree of the representation is defined as the dimension of as a -vector space.
For a finite group, the degrees of irreducible representations are important numbers. Further information: degrees of irreducible representations