English

Non-associative Ore extensions

Rings and Algebras 2016-09-20 v3

Abstract

We introduce non-associative Ore extensions, S=R[X;σ,δ]S = R[X ; \sigma , \delta], for any non-associative unital ring RR and any additive maps σ,δ:RR\sigma,\delta : R \rightarrow R satisfying σ(1)=1\sigma(1)=1 and δ(1)=0\delta(1)=0. In the special case when δ\delta is either left or right RδR_{\delta}-linear, where Rδ=ker(δ)R_{\delta} = \ker(\delta), and RR is δ\delta-simple, i.e. {0}\{ 0 \} and RR are the only δ\delta-invariant ideals of RR, we determine the ideal structure of the non-associative differential polynomial ring D=R[X;idR,δ]D = R[X ; \mathrm{id}_R , \delta]. Namely, in that case, we show that all ideals of DD are generated by monic polynomials in the center Z(D)Z(D) of DD. We also show that Z(D)=Rδ[p]Z(D) = R_{\delta}[p] for a monic pRδ[X]p \in R_{\delta}[X], unique up to addition of elements from Z(R)δZ(R)_{\delta}. Thereby, we generalize classical results by Amitsur on differential polynomial rings defined by derivations on associative and simple rings. Furthermore, we use the ideal structure of DD to show that DD is simple if and only if RR is δ\delta-simple and Z(D)Z(D) equals the field RδZ(R)R_{\delta} \cap Z(R). This provides us with a non-associative generalization of a result by \"{O}inert, Richter, and Silvestrov. This result is in turn used to show a non-associative version of a classical result by Jordan concerning simplicity of DD in the cases when the characteristic of the field RδZ(R)R_{\delta} \cap Z(R) is either zero or a prime. We use our findings to show simplicity results for both non-associative versions of Weyl algebras and non-associative differential polynomial rings defined by monoid/group actions on compact Hausdorff spaces.

Keywords

Cite

@article{arxiv.1509.01436,
  title  = {Non-associative Ore extensions},
  author = {Patrik Nystedt and Johan Öinert and Johan Richter},
  journal= {arXiv preprint arXiv:1509.01436},
  year   = {2016}
}

Comments

19 pages

R2 v1 2026-06-22T10:49:14.504Z