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In mathematics, particularly the theory of C *-algebras, a graph C *-algebra is a universal C *-algebra associated to a directed graph. They form a rich class of C *-algebras encompassing Cuntz algebras, Cuntz-Krieger algebras, the Toeplitz algebra, etc. Also every AF-algebra is Morita equivalent〔D. Drinen,''Viewing AF-algebras as graph algebras'', Proc. Amer. Math. Soc., 128 (2000), pp. 1991–2000.〕 to a graph C *-algebra. As the structure of graph C *-algebras is fairly tractable with computable invariants, they play an important part in the classification theory of C *-algebras. ==Definition== Let be a directed graph with a countable set of vertices , a countable set of edges , and maps identifying the range and source of each edge, respectively. The graph C *-algebra corresponding to , denoted by , is the universal C *-algebra generated by mutually orthogonal projections and partial isometries with mutually orthogonal ranges such that : (i) for all (ii) whenever (iii) for all . 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Graph C*-algebra」の詳細全文を読む スポンサード リンク
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