Spectral constants for the quantum annulus

Fuente: arXiv
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Hauptverfasser: Pal, Sourav, Pascoe, James E., Tomar, Nitin
Format: Preprint
Veröffentlicht: 2026
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author Pal, Sourav
Pascoe, James E.
Tomar, Nitin
author_facet Pal, Sourav
Pascoe, James E.
Tomar, Nitin
contents We find several new estimates for the spectral constants $K(\mathbb A_r)$ for which a closed annulus $\overline{\mathbb A}_r$ or closed polyannulus $\overline{\mathbb A}^n_r$ is a $K$-spectral set for operators in the quantum annulus $\mathbb Q \mathbb A_r$. We give two alternative proofs to an existing estimate of spectral constant. The first proof capitalizes a dilation theorem due to McCullough and Pascoe, while the second proof involves a certain variety in the Euclidean biball. For commuting and doubly commuting operators in $\mathbb Q \mathbb A_r$, we find upper and lower bounds for the smallest spectral constants.
format Preprint
id arxiv_https___arxiv_org_abs_2601_17560
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Spectral constants for the quantum annulus
Pal, Sourav
Pascoe, James E.
Tomar, Nitin
Functional Analysis
Complex Variables
Operator Algebras
We find several new estimates for the spectral constants $K(\mathbb A_r)$ for which a closed annulus $\overline{\mathbb A}_r$ or closed polyannulus $\overline{\mathbb A}^n_r$ is a $K$-spectral set for operators in the quantum annulus $\mathbb Q \mathbb A_r$. We give two alternative proofs to an existing estimate of spectral constant. The first proof capitalizes a dilation theorem due to McCullough and Pascoe, while the second proof involves a certain variety in the Euclidean biball. For commuting and doubly commuting operators in $\mathbb Q \mathbb A_r$, we find upper and lower bounds for the smallest spectral constants.
title Spectral constants for the quantum annulus
topic Functional Analysis
Complex Variables
Operator Algebras
url https://arxiv.org/abs/2601.17560