A condition that a normal operator have a closed numerical range
نویسندگان
چکیده
منابع مشابه
Spectrum, Numerical Range and Davis-wielandt Shell of a Normal Operator
We denote the numerical range of the normal operator T by W (T). A characterization is given to the points inW (T) that lie on the boundary. The collection of such boundary points together with the interior of the the convex hull of the spectrum of T will then be the set W (T). Moreover, it is shown that such boundary points reveal a lot of information about the normal operator. For instance, s...
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متن کاملبررسی اختلال معادلات ماتریسی x+a^*f(x)a=q
در این پایان نامه ابتدا شرایط وجود جواب برای معادلات ماتریسی و غیر خطی x+a^*f(x)a=q را بررسی نموده سپس به تحلیل اختلال در معادلات مذکور می پردازیم. در هر مبحث برای بیان و توضیح مطالب قضایا و مثال های عددی متعدد آورده شده است.
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ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 1957
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-1957-0094711-2