2007/02/13 by Katsunori Kawamura, Kawamura, Katsunori
Mathematics · #47L55 #81T05 #FOS: Mathematics #Operator Algebras (math.OA) #math.OA #msc:47L55 #msc:81T05
paper · pdf · doi:10.48550/arxiv.math/0702355
18 pages
arxiv created 2007/03/14 · arxiv updated 2009/12/01
We show that a tensor product among representation of certain C*-algebras induces a bialgebra. Let \cal O* be the smallest unitization of the direct sum of Cuntz algebras \cal O*≡ \bf C⊕ \cal O2⊕ \cal O3⊕\cal O4⊕ .... We show that there exists a non-cocommutative comultiplication Δ and a counit ε of \cal O*. From Δ,\vep and the standard algebraic structure, \cal O* is a C*-bialgebra. Furthermore we show the following: (i) The antipode on \cal O* never exist. (ii) There exists a unique Haar state on \cal O*. (iii) For a certain one-parameter bialgebra automorphism group of \cal O*, a KMS state on \cal O* exists.