The possible shapes of numerical ranges
نویسنده
چکیده
Which convex subsets of C are the numerical range W (A) of some matrix A? This paper gives a precise characterization of these sets. In addition to this we show that for any A there exists a symmetric B of the same size such that W (A) = W (B) thereby settling an open question from [2]. Mathematics Subject Classification (2000). Primary 47A12.
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تاریخ انتشار 2011