Line segments and elliptic arcs on the boundary of a numerical range
| dc.citation.epage | 142 | en_US |
| dc.citation.issue | 1-2 | en_US |
| dc.citation.spage | 131 | en_US |
| dc.citation.volume | 56 | en_US |
| dc.contributor.author | Gau, Hwa-Long | en_US |
| dc.contributor.author | Wu, Pei Yuan | en_US |
| dc.contributor.department | 應用數學系 | zh_TW |
| dc.contributor.department | Department of Applied Mathematics | en_US |
| dc.date.accessioned | 2014-12-08T15:45:11Z | |
| dc.date.available | 2014-12-08T15:45:11Z | |
| dc.date.issued | 2008 | en_US |
| dc.description.abstract | For an n-by-n complex matrix A, we consider the numbers of line segments and elliptic arcs on the boundary partial derivative W(A) of its numerical range. We show that (a) if n >= 4 and A has an (n-1)-by-(n-1) submatrix B with W(B) an elliptic disc, then there can be at most 2n-2 line segments on partial derivative W(A), and (b) if n >= 3, then partial derivative W(A) contains at most (n-2) arcs of any ellipse. Moreover, both upper bounds are sharp. For nilpotent matrices, we also obtain analogous results with sharper bounds. | en_US |
| dc.identifier.doi | 10.1080/03081080701396051 | en_US |
| dc.identifier.issn | 0308-1087 | en_US |
| dc.identifier.journal | LINEAR & MULTILINEAR ALGEBRA | en_US |
| dc.identifier.uri | http://dx.doi.org/10.1080/03081080701396051 | en_US |
| dc.identifier.uri | https://ir.lib.nycu.edu.tw/handle/11536/30453 | |
| dc.identifier.wosnumber | WOS:000251676600009 | |
| dc.language.iso | en_US | en_US |
| dc.subject | numerical range | en_US |
| dc.subject | nilpotent matrix | en_US |
| dc.title | Line segments and elliptic arcs on the boundary of a numerical range | en_US |
| dc.type | Article; Proceedings Paper | en_US |