## Essential norm of the difference of composition operators on Bloch space.(English)Zbl 1220.47045

Summary: Let $$\varphi$$ and $$\psi$$ be holomorphic self-maps of the unit disk, and denote by $$C_{\varphi }$$, $$C_{\psi }$$ the induced composition operators. This paper gives some simple estimates of the essential norm for the difference of composition operators $$C_{\varphi }-C_{\psi }$$ from Bloch spaces to Bloch spaces in the unit disk. Compactness of the difference is also characterized.

### MSC:

 47B38 Linear operators on function spaces (general) 47B33 Linear composition operators 46E15 Banach spaces of continuous, differentiable or analytic functions 30H30 Bloch spaces
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### References:

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