Abstract
We prove that von Neumann’s inequality holds for circulant contractions. We show that every complex polynomial over is associated to a constant such that von Neumann’s inequality can hold up to , for -tuples of commuting contractions on a Hilbert space. We characterise complex polynomials over in which . We introduce the properties of upper (or lower) complex triangular Toeplitz matrices. We show that von Neumann’s inequality holds for -tuples of upper (or lower) complex triangular Toeplitz contractions. We construct contractive homomorphisms.
Citation
Joachim Moussounda Mouanda. "On von Neumann's inequality for complex triangular Toeplitz contractions." Rocky Mountain J. Math. 50 (1) 213 - 224, Febuary 2020. https://doi.org/10.1216/rmj.2020.50.213
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