Definition
Elementary abelian group C_p^n
Additive group of a finite vector space over the prime field.
Let be prime and let be an integer. The elementary abelian group is the additive group of , with coordinatewise addition. Equivalently it is the direct product of copies of the cyclic group of order .
Order and simplicity
Its order is , and every nonzero element has order . The case is cyclic of prime order and simple. For , a one-dimensional subspace is proper nontrivial normal, so simplicity fails.
Structure being selected
This record selects the additive group structure. Linear maps over and group homomorphisms between elementary abelian -groups agree, because repeated addition supplies scalar multiplication by every element of the prime field.