Some Estimates of Certain Subnormal and Hyponormal Derivations
We prove that if 𝐴 and 𝐵∗ are subnormal operators and 𝑋 is a bounded linear operator such that 𝐴𝑋−𝑋𝐵 is a Hilbert-Schmidt operator, then 𝑓(𝐴)𝑋−𝑋𝑓(𝐵) is also a Hilbert-Schmidt operator and ‖𝑓(𝐴)𝑋−𝑋𝑓(𝐵)‖2≤𝐿‖𝐴𝑋−𝑋𝐵‖2 for 𝑓 belongs to a certain class of functions. Furthermore, we investigate the simil...
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| Format: | Article |
| Language: | English |
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Hindawi Limited
2008-01-01
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| Series: | International Journal of Mathematics and Mathematical Sciences |
| Online Access: | http://dx.doi.org/10.1155/2008/362409 |