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arXiv · 1008.3733

Leibniz Seminorms and Best Approximation from C*-subalgebras

Marc A. Rieffel
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Abstract

We show that if B is a C*-subalgebra of a C*-algebra A such that B contains a bounded approximate identity for A, and if L is the pull-back to A of the quotient norm on A/B, then L is strongly Leibniz. In connection with this situation we study certain aspects of best approximation of elements of a unital C*-algebra by elements of a unital C*-subalgebra.

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Marc A. Rieffel. 2010-08-23. Leibniz Seminorms and Best Approximation from C*-subalgebras. https://doi.org/10.1007/s11425-011-4318-2

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