English

Jacobson radicals of Ore extensions

Rings and Algebras 2024-06-17 v2

Abstract

Let RR be a ring, σ\sigma be an automorphism of RR, and DD be a σ\sigma-derivation on RR. We will show that if RR is an algebra over a field of characteristic 00 and DD is qq-skew, then J(R[x;σ,D])=IR+I0J(R[x;\sigma,D])=I\cap R+I_0 where I={rR:rxJ(R[x;σ,D])}I=\{r\in R : rx\in J(R[x;\sigma,D])\} and I0={i1rixi:riI}I_0=\{\sum_{i\geq 1}r_ix^i: r_i\in I\}. We will prove that J(R[x;σ,D])RJ(R[x;\sigma,D])\cap R is nil if σ\sigma is locally torsion and one of the following conditions is given: (1) RR is a PI-ring, (2) RR is an algebra over a field of characteristic p>0p>0 and DD is a locally nilpotent derivation such that σD=Dσ\sigma D=D\sigma. This answers partially an open question by Greenfeld, Smoktunowicz and Ziembowski.

Keywords

Cite

@article{arxiv.2405.16342,
  title  = {Jacobson radicals of Ore extensions},
  author = {Jooyoung Shin},
  journal= {arXiv preprint arXiv:2405.16342},
  year   = {2024}
}

Comments

The proofs of Theorem 2 and Theorem 3 were corrected