English

All dihedral division algebras of degree five are cyclic

Rings and Algebras 2014-02-04 v1

Abstract

Rowen and Saltman proved that every division algebra which is split by a dihedral extension of degree 2n2n of the center, nn odd, is in fact cyclic. The proof requires roots of unity of order nn in the center. We show that for n=5n=5, this assumption can be removed. It then follows that 5 ⁣ ⁣ ⁣Br(F){}_{5\!\!\!\:}Br(F), the 55-torsion part of the Brauer group, is generated by cyclic algebras, generalizing a result of Merkurjev on the 22 and 33 torsion parts.

Keywords

Cite

@article{arxiv.1402.0340,
  title  = {All dihedral division algebras of degree five are cyclic},
  author = {Eliyahu Matzri},
  journal= {arXiv preprint arXiv:1402.0340},
  year   = {2014}
}