| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4632513 | Applied Mathematics and Computation | 2010 | 7 Pages |
Abstract
The problem formulated in the title is investigated. The case of nilpotent matrices of size at most 4 allows a unitary treatment. The numerical range of a nilpotent matrix M of size at most 4 is circular if and only if the traces tr MâM2 and tr MâM3 are null. The situation becomes more complicated as soon as the size is 5. The conditions under which a 5Ã5 nilpotent matrix has circular numerical range are thoroughly discussed.
Related Topics
Physical Sciences and Engineering
Mathematics
Applied Mathematics
Authors
Valentin Matache, Mihaela T. Matache,