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Dual exponential polynomials and a problem of Ozawa

Part of: Entire and meromorphic functions, and related topics

Published online by Cambridge University Press:  16 June 2021

Janne Heittokangas ,
Katsuya Ishizaki ,
Kazuya Tohge  and
Zhi-Tao Wen
Janne Heittokangas
Affiliation:
Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland (janne.heittokangas@uef.fi)
Katsuya Ishizaki
Affiliation:
Faculty of Liberal Arts, The Open University of Japan, Mihama-ku, Chiba, Japan (ishizaki@ouj.ac.jp)
Kazuya Tohge
Affiliation:
College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan (tohge@se.kanazawa-u.ac.jp)
Zhi-Tao Wen*
Affiliation:
Department of Mathematics, Shantou University, Daxue Road No. 243, Shantou 515063, China (zhtwen@stu.edu.cn)
*
*Corresponding author
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Abstract

Complex linear differential equations with entire coefficients are studied in the situation where one of the coefficients is an exponential polynomial and dominates the growth of all the other coefficients. If such an equation has an exponential polynomial solution $f$, then the order of $f$ and of the dominant coefficient are equal, and the two functions possess a certain duality property. The results presented in this paper improve earlier results by some of the present authors, and the paper adjoins with two open problems.

Keywords

Dual exponential polynomialsexponential sumfinite orderlinear differential equationOzawa's problemvalue distribution

MSC classification

Primary: 30D15: Special classes of entire functions and growth estimates
Secondary: 30D35: Distribution of values, Nevanlinna theory
Type
Research Article
Information
Proceedings of the Royal Society of Edinburgh Section A: Mathematics , Volume 152 , Issue 3 , June 2022 , pp. 701 - 719
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Copyright
Copyright © The Author(s) 2021. Published by Cambridge University Press on behalf of The Royal Society of Edinburgh

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