摘要
Let A be an n × n (complex) matrix. Recall that the numerical range W (A) of A is the set {〈Ax, x〉: x ∈ ℂn, ||x|| = 1} in the plane, where 〈·, ·) denotes the usual inner product in ℂn. In this paper a series of tests is given, allowing one to determine when the numerical range of a 4 × 4 matrix A is an elliptic disc.
| 原文 | ???core.languages.en_GB??? |
|---|---|
| 頁（從 - 到） | 117-128 |
| 頁數 | 12 |
| 期刊 | Taiwanese Journal of Mathematics |
| 卷 | 10 |
| 發行號 | 1 |
| DOIs | |
| 出版狀態 | 已出版 - 1月 2006 |