Conditions for the generalized numerical range to be real
type: Item
instance of: scholarly article
title: Conditions for the generalized numerical range to be real
zbMATH Open document ID: 0583.15015
DOI: 10.1016/0024-3795(85)90249-6
author: Marvin Marcus
author: Markus Sandy
published in: Linear Algebra and its Applications
publication date: 1985-01-01T00:00:00Z
review text: Let C and A be given \(n\times n\) matrices. The classical numerical range \(W(CU^*AU)\) is contained in the real axis for all unitary U iff at least one of C and A is scalar and their product is Hermitian. The authors also investigate two generalized numerical ranges and describe the situations where these are real, or contained in a line parallel to the real axis.
Mathematics Subject Classification ID: 15A60
Mathematics Subject Classification ID: 15B57
zbMATH DE Number: 3933240
zbMATH Keywords: numerical range
zbMATH Keywords: Hermitian
reviewed by: Jaroslav Zemánek
MaRDI profile type: Publication
full work available at URL: 0024-3795(85)90249-6
OpenAlex ID: W1981731879
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description: scientific article; zbMATH DE number 3933240