English

Reconstructing the Bost--Connes semigroup actions from K-theory

Operator Algebras 2018-07-16 v2 Number Theory

Abstract

We complete the classification of Bost--Connes systems. We show that two Bost--Connes C*-algebras for number fields are isomorphic if and only if the original semigroups actions are conjugate. Together with recent reconstruction results in number theory by Cornelissen--de Smit--Li--Marcolli--Smit, we conclude that two Bost--Connes C*-algebras are isomorphic if and only if the original number fields are isomorphic.

Keywords

Cite

@article{arxiv.1709.03281,
  title  = {Reconstructing the Bost--Connes semigroup actions from K-theory},
  author = {Yosuke Kubota and Takuya Takeishi},
  journal= {arXiv preprint arXiv:1709.03281},
  year   = {2018}
}

Comments

28 pages. Section 2 and 4 are rewritten

R2 v1 2026-06-22T21:38:46.512Z