Field of values and spectra of positive definite multiples
Charles R. Johnson · Journal of Research of the National Bureau of Standards Section B Mathematical Sciences · 1974
Suppose 0 ~AEC ad AEM,,(C).We show constructively that A is an eigenva lue of HA for some H *= H > 0 if and only if A=x*Ax for some XEC".The characterization of H-stable mat rices is then an e asy coro ll ary. Key words: Eigenva lu es; field of values; H-