Matrices with hyperbolical Krein space numerical range

被引：0
作者：
Bebiano, N. [1 ,2 ]
Lemos, R. [3 ,4 ]
Soares, G. [5 ,6 ]
机构：
[1] Univ Coimbra, CMUC, P-3001501 Coimbra, Portugal
[2] Univ Coimbra, Math Dept, P-3001501 Coimbra, Portugal
[3] Univ Aveiro, CIDMA, P-3810193 Aveiro, Portugal
[4] Univ Aveiro, Math Dept, P-3810193 Aveiro, Portugal
[5] Univ Tras Os Montes & Alto Douro, CMAT UTAD, P-5000801 Vila Real, Portugal
[6] Univ Tras Os Montes & Alto Douro, Math Dept, P-5000801 Vila Real, Portugal
来源：
ADVANCES IN OPERATOR THEORY | 2025年 / 10卷 / 01期
关键词：
Numerical range; Krein space; Centrosymmetric matrices; Tridiagonal matrices; Hyperbolical range theorem; KIPPENHAHN CURVES; OPERATORS; GEOMETRY;
D O I：
10.1007/s43036-024-00399-6
中图分类号：
O1 [数学];
学科分类号：
0701 ; 070101 ;
摘要：
This paper is devoted to matrices with hyperbolical Krein space numerical range. This shape characterizes the 2-by-2 case and persists for certain classes of matrices, independently of their size. Necessary and sufficient conditions for low dimensional tridiagonal matrices to have this shape are obtained involving only the matrix entries.
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页数：19
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