@article{be270b1eba574350b26a775593b469d3,
title = "On the magic square C*-algebra of size 4",
abstract = "In this paper, we investigate the structure of the magic square C*-algebra A(4) of size 4. We show that a certain twisted crossed product of A(4) is isomorphic to the homogeneous C*-algebra M4 (FORMULA PRESENT (RP3 )). Using this result, we show that A(4) is isomorphic to the fixed point algebra of M4 (C (RP3 )) by a certain action. From this concrete realization of A(4), we compute the K-groups of A(4) and their generators.",
keywords = "46L55, 46L80, C*-algebra, K-theory. 2020 Mathematics Subject Classification: 46L05, magic square C*-algebra, twisted crossed product",
author = "Takeshi Katsura and Masahito Ogawa and Airi Takeuchi",
note = "Funding Information: The first named author is supported by JSPS KAKENHI Grant Number JP18K03345. The third named author is supported by Masason Foundation. Keywords: C*-algebra, magic square C*-algebra, twisted crossed product, K-theory. 2020 Mathematics Subject Classification: 46L05, 46L55, 46L80. Publisher Copyright: {\textcopyright} 2022, Universite Clermont Auvergne. All rights reserved.",
year = "2022",
doi = "10.5802/ambp.408",
language = "English",
volume = "29",
pages = "99--148",
journal = "Annales Mathematiques Blaise Pascal",
issn = "1259-1734",
publisher = "Universite Clermont Auvergne",
number = "1",
}