CIRCULARITY OF THE NUMERICAL RANGE

Authors
CHIEN MT TAM BS
Citation
Mt. Chien et Bs. Tam, CIRCULARITY OF THE NUMERICAL RANGE, Linear algebra and its applications, 201, 1994, pp. 113-133
Citations number
7
Categorie Soggetti
Mathematics,Mathematics
Journal title
Linear algebra and its applications → ACNP
ISSN journal
00243795
Volume
201
Year of publication
1994
Pages
113 - 133
Database
ISI
SICI code
0024-3795(1994)201:<113:COTNR>2.0.ZU;2-S
Abstract
An equivalent condition on a 3-square complex or a 4-square real upper triangular matrix is found for its numerical range to be a circular d isk centered at the origin. Sufficient conditions for the circularity of the numerical range of certain sparse matrices are also given in te rms of graphs.