English

Extensions and Pullbacks in QB-rings

Rings and Algebras 2007-05-23 v1 Operator Algebras

Abstract

We prove a new extension result for QBQB-rings that allows us to examine extensions of rings where the ideal is purely infinite and simple. We then use this result to explore various constructions that provide new examples of QBQB-rings. More concretely, we show that a surjective pullback of two QBQB-rings is usually again a QBQB-ring. Specializing to the case of an extension of a semi-prime ideal II of a unital ring RR, the pullback setting leads naturally to the study of rings whose multiplier rings are QBQB-rings. For a wide class of regular rings, we give necessary and sufficient conditions for their multiplier rings to be QBQB-rings. Our analysis is based on the study of extensions and the use of non-stable KK-theoretical techniques.

Keywords

Cite

@article{arxiv.math/0107104,
  title  = {Extensions and Pullbacks in QB-rings},
  author = {Pere Ara and Gert K. Pedersen and Francesc Perera},
  journal= {arXiv preprint arXiv:math/0107104},
  year   = {2007}
}

Comments

20 pages