Linear representation theory of cyclic group:Z3: Difference between revisions

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===Character table===
===Character table===


Let <math>\omega</math> be a primitive cube root of unity.
Let <math>\omega</math> be a primitive cube root of unity. In terms of the <math>i</math>-notation, <math>\omega</math> can be taken as <math>e^{2\pi i/3}</math> or <math>\cos(2\pi/3) + i\sin(2\pi/3)</math>, which is <math>(-1 + i\sqrt{3})/2</math>. <math>\omega^2</math> is the other primitive cube root of unity, and is given as <math>e^{-2\pi i/3}</math> or <math>\cos(2\pi/3) - i\sin(2\pi/3)</math> or <math>(-1 - i\sqrt{3))/2</math>.


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Revision as of 22:20, 3 February 2011

This article gives specific information, namely, linear representation theory, about a particular group, namely: cyclic group:Z3.
View linear representation theory of particular groups | View other specific information about cyclic group:Z3

Over the complex numbers

The cyclic group of order three, being an Abelian group, has the property that all its irreducible representations are one-dimensional, and all representations are thus completely reducible in terms of one-dimensional representations. There are three irreducible representations, the trivial representation, and two representations sending the generators to the cube roots of unity, in different orders.

Character table

Let ω be a primitive cube root of unity. In terms of the i-notation, ω can be taken as e2πi/3 or cos(2π/3)+isin(2π/3), which is (−1+i3)/2. ω2 is the other primitive cube root of unity, and is given as e−2πi/3 or cos(2π/3)−isin(2π/3) or Failed to parse (syntax error): {\displaystyle (-1 - i\sqrt{3))/2} .

Representation/Conjugacy class e (identity element) x (generator) x2 (generator)
trivial representation 1 1 1
one nontrivial representation 1 ω ω2
the other (conjugate) nontrivial representation 1 ω2 ω