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  • Fixed point free automorphi...
    Childs, Lindsay N.

    Finite fields and their applications, July 2012, 2012-07-00, Volume: 18, Issue: 4
    Journal Article

    Let G=Fq⋊〈β〉 be the semidirect product of the additive group of the field of q=pn elements and the cyclic group of order d generated by the invertible linear transformation β defined by multiplication by a power of a primitive root of Fq. We find an arithmetic condition on d so that every endomorphism of G is determined by its values on (1,1) and (0,β). When that is the case, we determine the fixed point free automorphisms of G. If d equals the odd part of q−1 then we count the fixed point free automorphisms of G—such exist only when p is a Fermat prime.