Submitted:
24 August 2026
Posted:
25 August 2026
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Abstract
In this paper, we obtain new criteria for the norm and the essential norm of composition
operators acting from the space \(\mathcal{H}^{\infty}\) of bounded harmonic mappings into
weighted harmonic Bloch spaces \(\mathcal{B}^{\alpha}_H\), \(0< \alpha< \infty\), on the unit disk.
These criteria are expressed in terms of the asymptotic behavior of the sequence
\(\{\|C_{\psi}q_k\|_{\mathcal{B}^{\alpha}_H}\}_{k\ge0}\) and of a family
of M\"obius-invariant test functions, yielding symbol-based characterizations of boundedness and of compactness, and hence of the essential norm for
\(C_{\psi}:\mathcal{H}^{\infty} \to \mathcal{B}^{\alpha}_H\).
Keywords:
omposition operators
; essential norm
; weighted harmonic Bloch space
; harmonic \(\mathcal{H}^{\infty}\) space
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