On the continuity of the J -spectral factorization mapping
نویسنده
چکیده
The continuity of the mapping which associates a J-spectral factor to a spectral density is analyzed. For the class of essentially bounded functions on the imaginary axis that are bounded away from zero it is well known that this mapping, even for the scalar case, is not continuous. In this paper three results concerning the continuity of the mapping which associates a J-spectral factor to a spectral density are provided for matrix-valued functions in the Wiener class. One of them is well known, and the other two are extensions of theorems concerning the continuity of the spectral factorization mapping.
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