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Licensed Unlicensed Requires Authentication Published by De Gruyter August 10, 2012

Free products and wild nearfields à la B. H. Neumann and Hans Zassenhaus

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From the journal Forum Mathematicum


The modular group PSL2 ℤ contains many subgroups that are sharply transitive on the rational projective line ℚ ∪ ∞. If the field E is a purely transcendental extension of transcendency degree |E|, then PSL2E contains free subgroups that are sharply transitive on the projective line E ∪ ∞. This yields wild infinite nearfields and sharply two-transitive permutation groups.

Received: 2012-5-10
Published Online: 2012-8-10
Published in Print: 2014-11-1

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