Abstract
We compute the monoid V(L K (E)) of isomorphism classes of finitely generated projective modules over certain graph algebras L K (E), and we show that this monoid satisfies the refinement property and separative cancellation. We also show that there is a natural isomorphism between the lattice of graded ideals of L K (E) and the lattice of order-ideals of V(L K (E)). When K is the field \(\mathbb C\) of complex numbers, the algebra \(L_{\mathbb C}(E)\) is a dense subalgebra of the graph C *-algebra C *(E), and we show that the inclusion map induces an isomorphism between the corresponding monoids. As a consequence, the graph C*-algebra of any row-finite graph turns out to satisfy the stable weak cancellation property.
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The first author was partially supported by the DGI and European Regional Development Fund, jointly, through Project BFM2002-01390, the second and the third by the DGI and European Regional Development Fund, jointly, through Project MTM2004-00149 and by PAI III grant FQM-298 of the Junta de Andalucía. Also, the first and third authors are partially supported by the Comissionat per Universitats i Recerca de la Generalitat de Catalunya.
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Ara, P., Moreno, M.A. & Pardo, E. Nonstable K-theory for Graph Algebras. Algebr Represent Theor 10, 157–178 (2007). https://doi.org/10.1007/s10468-006-9044-z
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DOI: https://doi.org/10.1007/s10468-006-9044-z
Key words
- graph algebra
- weak cancellation
- separative cancellation
- refinement monoid
- nonstable K-theory
- ideal lattice