Positive combinations of projections in von Neumann algebras and purely infinite simple C*-algebras

V. Kaftal; P. W. Ng; S. Zhang

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arXiv · 1201.4844

Positive combinations of projections in von Neumann algebras and purely infinite simple C*-algebras

V. Kaftal·P. W. Ng·S. Zhang

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Abstract

We give an overview of the question: which positive elements in an operator algebra can be written as a linear combination of projections with positive coefficients. A special case of independent interest is the question of which positive elements can be written as a sum of finitely many projections. We focus on von Neumann algebras, on purely infinite simple C*-algebras, and on their associated multiplier algebras.

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BibTeX RIS

V. Kaftal, P. W. Ng, S. Zhang. 2012-01-23. Positive combinations of projections in von Neumann algebras and purely infinite simple C*-algebras. https://arxiv.org/abs/1201.4844

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