English

Patching subfields of division algebras

Rings and Algebras 2009-10-23 v2 Algebraic Geometry

Abstract

Given a field F, one may ask which finite groups are Galois groups of field extensions E/F such that E is a maximal subfield of a division algebra with center F. This question was originally posed by Schacher, who gave partial results over the field of rational numbers. Using patching, we give a complete characterization of such groups in the case that F is the function field of a curve over a complete discretely valued field with algebraically closed residue field of characteristic zero, as well as results in related cases.

Keywords

Cite

@article{arxiv.0904.1594,
  title  = {Patching subfields of division algebras},
  author = {David Harbater and Julia Hartmann and Daniel Krashen},
  journal= {arXiv preprint arXiv:0904.1594},
  year   = {2009}
}

Comments

20 pages. In Section 3 some statements were strengthened and proofs simplified. At the end of Section 4 the definition of the rank two valuation was fixed

R2 v1 2026-06-21T12:49:57.874Z