On Conjugacy of Subalgebras of Graph C-Algebras

  • Piotr Kielanowski
  • Anatol Odzijewicz
  • Emma Previato
Conference paper
Part of the Trends in Mathematics book series (TM)


The problem of inner vs outer conjugacy of subalgebras of certain graph C*-algebras is investigated. For a large class of finite graphs E, we show that whenever α is a vertex-fixing quasi-free automorphism of the corresponding graph C*-algebra C* (E) such that α(DE) ≠ DE where DE is the canonical MASA in C*(E), then α(DE) ≠ ωDEω* for all unitaries ωC* (E). That is, the two MASAs DE and α(DE) of C*(E) are outer but not inner conjugate. For the Cuntz algebras On, we find a criterion which guarantees that a polynomial automorphism moves the canonical UHF subalgebra to a non-inner conjugate UHF subalgebra. The criterion is phrased in terms of rescaling of trace on diagonal projections.


C-functions S-functions graph C*-algebra Cuntz algebra MASA UHF-subalgebra automorphism inner and outer conjugacy. 

Mathematics Subject Classification (2000)

Primary 46L05 46L40. 


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Piotr Kielanowski
    • 1
  • Anatol Odzijewicz
    • 2
  • Emma Previato
    • 3
  1. 1.Departamento de FísicaCINVESTAVCiudad de MéxicoMexico
  2. 2.Institute of MathematicsUniversity of BialystokBialystokPoland
  3. 3.Department of Mathematics and StatisticsBoston UniversityBostonUSA

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