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Feb 20, 2016 at 17:01 vote accept John N.
Feb 20, 2016 at 16:38 answer added Nik Weaver timeline score: 4
Feb 20, 2016 at 13:47 comment added John N. Thank you very much for the help. I'll read Abrams' paper.
Feb 20, 2016 at 13:36 comment added Benjamin Steinberg I am not sure where to find a reference for the operator case. You can find this for Leavitt path algebras in the survey of Abrams on the first decade of Leavitt path algebras. I am sure the operator theory proof is essentially the same but as an algebraist I wouldn't know how to write it in a technically correct way.
Feb 20, 2016 at 13:28 comment added John N. Ok. So we can choose 1, and say that it is a generator of the K_0 group. Could you give me a reference or expand your comment in an answer that proves that the class of 1 is not zero? Thank you for the help
Feb 20, 2016 at 12:25 comment added Benjamin Steinberg Yes you are right it is equivalent to 1. But isn't the class of 1 the generator not 0 for n>2? All n of those idempotents are equivalent to 1 so the cuntz relation gives n[1]=[1].
Feb 20, 2016 at 12:19 comment added John N. @ Benjamin Steinberg: I am not sure. Probably I am wrong, but S_S_1^* is equivalent to 1 (S_1 is an isometry). However, the class of [1] is 0.
Feb 20, 2016 at 12:16 comment added Benjamin Steinberg I think it should correspond to the idempotent s_1s_1*
Feb 20, 2016 at 9:46 history asked John N. CC BY-SA 3.0