Abstract
We prove that if G is an analytic function in the unit disc such that G(z)→∞, as z→1, and B is an infinite Blaschke product whose sequence of zeros is contained in a Stolz angle with vertex at 1 then the function f=B⋅G is not a normal function.
We prove also some results on the asymptotic cluster set of a thin Blaschke product with positive zeros which are related with the question of the existence of non-normal outer functions with restricted mean growth of the derivative.
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The authors thankfully acknowledge partial support from the following grants. The first author: MTM2007-60854 (MICINN, Spain ); FQM-210 and P06-FQM01504 (Junta de Andalucía) and “Harmonic and Complex Analysis and Its Applications” (European Networking Programme, ESF). The second author: The Ramón and Cajal program and grants MTM2008-00145 and 2009SGR00420 (MICINN, Spain ). Both authors: MTM2008-02829-E and Ingenio Mathematica (i-MATH) No. CSD2006-00032 (MICINN, Spain).
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Girela, D., Suárez, D. On Blaschke products, Bloch functions and normal functions. Rev Mat Complut 24, 49–57 (2011). https://doi.org/10.1007/s13163-010-0027-6
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DOI: https://doi.org/10.1007/s13163-010-0027-6
Keywords
- Blaschke product
- Interpolating Blaschke sequence
- Thin Blaschke product
- Bloch function
- Normal function
- Outer function
- Mean Lipschitz spaces
