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arXiv · 2606.18369

Amenable traces and the joint numerical radius

Vern I. Paulsen·Mizanur Rahaman·Ebrahim Samei
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Abstract

We provide necessary and sufficient characterizations of the existence of an amenable trace on a C$^*$-algebra in terms of the joint free numerical radius of tuples of unitaries, isometries, and partial isometries in the algebra. We apply these results to obtain new obstructions to various lifting properties.

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Vern I. Paulsen, Mizanur Rahaman, Ebrahim Samei. 2026-06-16. Amenable traces and the joint numerical radius. https://arxiv.org/abs/2606.18369

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