A generalisation of Amitsur's A-polynomials Adam Owen; Susanne Pumplün — 2021 Communications in Mathematics We find examples of polynomials f ∈ D [ t ; σ , δ ] whose eigenring ℰ ( f ) is a central simple algebra over the field F = C ∩ Fix ( σ ) ∩ Const ( δ ) .
Sums of d th powers in non-commutative rings. Pumplün, Susanne — 2007 Beiträge zur Algebra und Geometrie