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Bibliographic Details
Main Authors: Koval, Vadym, Pagacz, Patryk
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2402.00673
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author Koval, Vadym
Pagacz, Patryk
author_facet Koval, Vadym
Pagacz, Patryk
contents We investigate the relation between the spectrum of matrix (or operator) polynomials and the Taylor spectrum of its coefficients. We prove that the polynomial of commuting matrices is singular, i.e. its spectrum is the whole complex plane, if and only if (0, 0, ... , 0) belongs to the Taylor spectrum of its coefficients. On the other hand we prove that this equivalence is not longer true if we consider the operators on infinite dimensional Hilbert space as coefficients of polynomial. As a consequence we could propose a new description of (Taylor) spectrum of k-tuple of matrices and we could disprove the conjecture previously proposed in the literature. Additionally, we pointed out the Kronecker forms of the pencils with commuting coefficients.
format Preprint
id arxiv_https___arxiv_org_abs_2402_00673
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On singular pencils with commuting coefficients
Koval, Vadym
Pagacz, Patryk
Spectral Theory
15A22, 15A27, 47A13, 15A60
We investigate the relation between the spectrum of matrix (or operator) polynomials and the Taylor spectrum of its coefficients. We prove that the polynomial of commuting matrices is singular, i.e. its spectrum is the whole complex plane, if and only if (0, 0, ... , 0) belongs to the Taylor spectrum of its coefficients. On the other hand we prove that this equivalence is not longer true if we consider the operators on infinite dimensional Hilbert space as coefficients of polynomial. As a consequence we could propose a new description of (Taylor) spectrum of k-tuple of matrices and we could disprove the conjecture previously proposed in the literature. Additionally, we pointed out the Kronecker forms of the pencils with commuting coefficients.
title On singular pencils with commuting coefficients
topic Spectral Theory
15A22, 15A27, 47A13, 15A60
url https://arxiv.org/abs/2402.00673