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Let V be a representation of a finite group G, and $v\in V$ - a nonzero vector. Put $u = \sum_{g\in G} gv.$ Then for any $g\in G$ we have $gu = u$ and therefore $$ is a subrepresentation of V.

I know there is an error here since there are irreducible representations of finite groups which are not one dimensional, but I can't see it. Could someone point it out?

Thank you.

1 Answers 1

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It is possible that $u$ is zero.

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    @Artem, You could have found this out by yourself by picking *any* irreducible representation of dimesion larger than one of *any* group! You should *always* look at examples.2012-09-03