Regular functions of restricted growth and their zeros in tangential regions
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- by C. N. Linden PDF
- Trans. Amer. Math. Soc. 275 (1983), 679-686 Request permission
Abstract:
For a given function $k$, positive, continuous, nondecreasing and unbounded on $[0,1)$, let ${A^{(k)}}$ denote the class of functions regular in the unit disc for which log $|f(z)| < k(|z|)$ when $|z| < 1$. Hayman and Korenblum have shown that a necessary and sufficient condition for the sets of positive zeros of all functions in ${A^{(k)}}$ to be Blaschke is that \[ \int _0^1 {\sqrt {(k(t)/(1 - t)) dt} } \] is finite. It is shown that the imposition of a further regularity condition on the growth of $k$ ensures that in some tangential region the zero set of each function in ${A^{(k)}}$ is also Blaschke.References
- W. K. Hayman and B. Korenblum, A critical growth rate for functions regular in a disk, Michigan Math. J. 27 (1980), no. 1, 21–30. MR 555833
- C. N. Linden, Functions regular in the unit circle, Proc. Cambridge Philos. Soc. 52 (1956), 49–60. MR 73695 E. C. Titchmarsh, The theory of functions, Oxford Univ. Press, London, 1939.
Additional Information
- © Copyright 1983 American Mathematical Society
- Journal: Trans. Amer. Math. Soc. 275 (1983), 679-686
- MSC: Primary 30C15; Secondary 30D15, 30D50
- DOI: https://doi.org/10.1090/S0002-9947-1983-0682724-9
- MathSciNet review: 682724