An envelope for the spectrum of a matrix

Psarrakos, PJ; Tsatsomeros, MJ

dc.contributor.author	Psarrakos, PJ	en
dc.contributor.author	Tsatsomeros, MJ	en
dc.date.accessioned	2014-03-01T02:07:37Z
dc.date.available	2014-03-01T02:07:37Z
dc.date.issued	2012	en
dc.identifier.issn	18951074	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29597
dc.subject	Cubic curve	en
dc.subject	Eigenvalue bounds	en
dc.subject	Numerical range	en
dc.title	An envelope for the spectrum of a matrix	en
heal.type	journalArticle	en
heal.identifier.primary	10.2478/s11533-011-0111-2	en
heal.identifier.secondary	http://dx.doi.org/10.2478/s11533-011-0111-2	en
heal.publicationDate	2012	en
heal.abstract	We introduce and study an envelope-type region e{open}(A) in the complex plane that contains the eigenvalues of a given n×n complex matrix A. e{open}(A) is the intersection of an infinite number of regions defined by cubic curves. The notion and method of construction of e{open}(A) extend the notion of the numerical range of A, F(A), which is known to be an intersection of an infinite number of half-planes; as a consequence, e{open}(A) is contained in F(A) and represents an improvement in localizing the spectrum of A. © 2012 Versita Warsaw and Springer-Verlag Wien.	en
heal.journalName	Central European Journal of Mathematics	en
dc.identifier.doi	10.2478/s11533-011-0111-2	en
dc.identifier.volume	10	en
dc.identifier.issue	1	en
dc.identifier.spage	292	en
dc.identifier.epage	302	en