Title :
Elliptic Numerical Ranges of 4 x 4 Matrices
Author :
Li, Hongkui ; Liu, Xueting
Author_Institution :
Coll. of Sci., Shandong Univ. of Technol., Zibo, China
Abstract :
Let A be a ntimesn complex matrix associated with f(z)=zn+a1zn-1+...+an-1z+an. Then the numerical range of A is defined to be W(A)={x* Ax:xisinCm /|x|=1}. In this paper, we study some properties of the Kippenhahn curve CR(A) firstly, and then discuss the necessary condition of W(A) (A is 4times4 reducible companion matrices) being an elliptic disc by making use of matrices Kronecker product and the Kippenhahn curve CR(A).
Keywords :
computational complexity; matrix algebra; Kippenhahn curve; Kronecker product; complex matrix; elliptic numerical ranges; reducible companion matrices; Algebra; Chromium; Educational institutions; Linear matrix inequalities; Matrices; Numerical analysis; Physics; Polynomials; Quantum mechanics; Companion matrix; Kronecker product; Numerical range; elliptic disc;
Conference_Titel :
Future Computer and Communication, 2009. FCC '09. International Conference on
Conference_Location :
Wuhan
Print_ISBN :
978-0-7695-3676-7
DOI :
10.1109/FCC.2009.56