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Linear representations of algebras and groups, Lie theory, associative algebras, multilinear algebra.

58 votes

How many square roots can a non-identity element in a group have?

Here is an elementary way to prove that there can´t be a finite group $G$ and non-identity $g\in G$ with $r_2(g)>\frac{5}{6}|G|$. Suppose that happens and call $S=\{x\in G; x^2=g\}$. Then of course th …
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