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Dimension of Null Spaces with Applications to Group Rings

Published online by Cambridge University Press:  20 November 2018

David Promislow
David Promislow*
Affiliation:
York University, Downsview, Ontario
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In this paper we investigate methods for estimating the dimension of the null space of operators in a finite W* algebra, the dimension being measured by the trace τ. For the most part we are concerned with operators A which are a finite linear combination of orthogonal unitaries. We give various results which show how certain information about the unitaries and the coefficients can be utilized to derive an upper bound for τ(NA) where NA is the null space of A.

Type
Research Article
Information
Canadian Journal of Mathematics , Volume 30 , Issue 2 , 01 April 1978 , pp. 289 - 300
Copyright
Copyright © Canadian Mathematical Society 1978

References

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