Essentially Convexoid Operators
Keyword(s):
Let H be a separable complex Hilbert space and let B(H) denote the algebra of all bounded linear operators on H. Let π be the quotient mapping from B(H) onto the Calkin algebra B(H)/K(H), where K(H) denotes all compact operators on B(H). An operator T ∈ B(H) is said to be convexoid[14] if the closure of its numerical range W(T) coincides with the convex hull co σ(T) of its spectrum σ(T). T ∈ B(H) is said to be essentially normal, essentially G1, or essentially convexoid if π(T) is normal, G1 or convexoid in B(H)/K(H) respectively.
1974 ◽
Vol 26
(1)
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pp. 115-120
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1985 ◽
Vol 26
(2)
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pp. 141-143
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1977 ◽
Vol 29
(5)
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pp. 1010-1030
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2015 ◽
Vol 17
(05)
◽
pp. 1450042
1980 ◽
Vol 21
(1)
◽
pp. 75-79
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