1 6 Ju n 20 04 Intersections of finite families of finite index
نویسنده
چکیده
We prove that finiteness of the index of the intersection of a finite set of finite index subalgebras in a von Neumann algebra (with small centre) is equivalent to the finite dimensionality of the algebra generated by the conditional expectations onto the subalgebras. Supported in part by NSF gramt DMS-9322675 and Marsden grant UOA520. Supported in part by NSF grant DMS-0200770.
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متن کامل4 Intersections of finite families of finite index
We prove that finiteness of the index of the intersection of a finite set of finite index subalgebras in a von Neumann algebra (with small centre) is equivalent to the finite dimensionality of the algebra generated by the conditional expectations onto the subalgebras. 2000 Mathematics Subject Classification. 46S99, 81R10.
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