English

Probl\`emes de plongement finis sur les corps non commutatifs

Number Theory 2021-03-23 v2

Abstract

We extend finite embedding problems over fields, a central notion in inverse Galois theory, to the situation of a skew field HH of finite dimension over its center hh. First, we show that solving a finite embedding problem over HH is equivalent to finding a solution to some finite embedding problem over hh fulfilling a polynomial constraint. Next, we show that every constant finite split embedding problem over the skew field of fractions H(t)H(t) with central indeterminate tt has a solution, if hh is an ample field. This is a non-commutative analogue of a deep result of Pop. More generally, we solve such finite embedding problems over the skew field of fractions H(t,σ)H(t, \sigma) of the twisted polynomial ring H[t,σ]H[t, \sigma], for some automorphisms σ\sigma of HH of finite order. Our results extend previous works on the inverse Galois problem over skew fields.

Keywords

Cite

@article{arxiv.2008.08333,
  title  = {Probl\`emes de plongement finis sur les corps non commutatifs},
  author = {Angelot Behajaina and Bruno Deschamps and François Legrand},
  journal= {arXiv preprint arXiv:2008.08333},
  year   = {2021}
}

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