Some properties for random power series $ (\mathcal{R}f)(z) = \sum\limits_{n = 0}^\infty a_n\epsilon_n z^n $ in $ Q_K $ spaces and $ Q_{K, 0} $ spaces were studied in this paper. It was proved that if the condition $ \sum\limits_{n = 1}^\infty n|a_n|^2 K(\frac{1}{n}) < \infty $ holds, then $ \mathcal{R}f\in Q_K $ a.s. Furthermore, this condition actually implied that $ \mathcal{R}f\in Q_{K, 0} $ a.s. As an application, the relationship between mean Lipschitz spaces and $ Q_K $ spaces was shown.
Citation: RuiLan ZhuGe, Xinxin Zhao, Yan Wu. Taylor coefficients condition and mean growth of random series in $ Q_K $ spaces[J]. AIMS Mathematics, 2026, 11(7): 21961-21972. doi: 10.3934/math.2026887
Some properties for random power series $ (\mathcal{R}f)(z) = \sum\limits_{n = 0}^\infty a_n\epsilon_n z^n $ in $ Q_K $ spaces and $ Q_{K, 0} $ spaces were studied in this paper. It was proved that if the condition $ \sum\limits_{n = 1}^\infty n|a_n|^2 K(\frac{1}{n}) < \infty $ holds, then $ \mathcal{R}f\in Q_K $ a.s. Furthermore, this condition actually implied that $ \mathcal{R}f\in Q_{K, 0} $ a.s. As an application, the relationship between mean Lipschitz spaces and $ Q_K $ spaces was shown.
| [1] |
R. Aulaskari, D. Girela, H. Wulan, Taylor coefficients and mean growth of the derivative of $Q_p$ functions, J. Math. Anal. Appl., 258 (2001), 415–428. https://doi.org/10.1006/jmaa.2000.7259 doi: 10.1006/jmaa.2000.7259
|
| [2] |
R. Aulaskari, D. A. Stegenga, J. Xiao, Some subclasses of BMOA and their characterization in terms of Carleson measures, Rocky Mountain J. Math., 26 (1996), 485–506. https://doi.org/10.1216/rmjm/1181072070 doi: 10.1216/rmjm/1181072070
|
| [3] | R. Aulaskari, D. A. Stegenga, R. Zhao, Random power series and $Q_p$, Proceedings of XVI Rolf Nevanlinna Colloquium at Joensuu, Walter de Gruyter Co, Berlin, New York, 1996. |
| [4] |
R. Aulaskari, J. Xiao, R. Zhao, On subspaces and subsets of BMOA and UBC, Analysis, 15 (1995), 101–121. https://doi.org/10.1524/anly.1995.15.2.101 doi: 10.1524/anly.1995.15.2.101
|
| [5] |
P. Duren, Random series and bounded mean oscillation, Michigan Math. J., 32 (1985), 81–86. https://doi.org/10.1307/mmj/1029003134 doi: 10.1307/mmj/1029003134
|
| [6] | P. L. Duren, Theory of $H^p$ spaces, Pure and Applied Mathematics, Academic Press New York-London, 1970. |
| [7] |
M. Essén, H. Wulan, On analytic and meromorphic functions and spaces of $Q_K$-type, Illinois J. Math., 46 (2002), 1233–1258. https://doi.org/10.1215/ijm/1258138477 doi: 10.1215/ijm/1258138477
|
| [8] |
M. Essén, H. Wulan, J. Xiao, Several function-theoretic characterizations of Möbius invariant $Q_K$ spaces, J. Funct. Anal., 230 (2006), 78–115. https://doi.org/10.1016/j.jfa.2005.07.004 doi: 10.1016/j.jfa.2005.07.004
|
| [9] | J. B. Garnett, Bounded analytic functions, Graduate Texts in Mathematics, Springer New York, 2007. https://doi.org/10.1007/0-387-49763-3 |
| [10] | J. P. Kahane, Some random series of functions, Cambridge: Cambridge University Press, 1985. |
| [11] |
C. Liu, Multipliers for Dirichlet type spaces by randomization, Banach J. Math. Anal., 14 (2020), 935–949. https://doi.org/10.1007/s43037-019-00046-w doi: 10.1007/s43037-019-00046-w
|
| [12] |
J. E. Littlewood, Mathematical notes (13): on mean values of power series (Ⅱ), J. London Math. Soc., s1-5 (1930), 179–182. https://doi.org/10.1112/jlms/s1-5.3.179 doi: 10.1112/jlms/s1-5.3.179
|
| [13] | H. Li, Y. Wu, Random power series in $Q_{p, 0}$ spaces, J. Funct. Spaces, 2021, 1–5. https://doi.org/10.1155/2021/1449080 |
| [14] |
R. E. A. C. Paley, A. Zygmund, On some series of functions(1), Math. Proc. Cambridge Philos. Soc., 26 (1930), 337–357. https://doi.org/10.1017/s0305004100016078 doi: 10.1017/s0305004100016078
|
| [15] |
C. Pommerenke, On Bloch functions, J. London Math. Soc., 2 (1970), 689–695. https://doi.org/10.1112/jlms/2.part_4.689 doi: 10.1112/jlms/2.part_4.689
|
| [16] |
Y. Qi, Y. Wu, On $Q_K(p)$-Teichmüller spaces, Acta Math. Sci., 44 (2024), 2283–2295. https://doi.org/10.1007/s10473-024-0613-1 doi: 10.1007/s10473-024-0613-1
|
| [17] |
W. T. Sledd, Random series which are BMO or Bloch, Michigan Math. J., 28 (1981), 259–266. https://doi.org/10.1307/mmj/1029002557 doi: 10.1307/mmj/1029002557
|
| [18] |
H. Wulan, K. Zhu, Lacunary series in $Q_K$ spaces, Studia Math., 178 (2007), 217–230. https://doi.org/10.4064/sm178-3-2 doi: 10.4064/sm178-3-2
|
| [19] | H. Wulan, K. Zhu, Möbius invariant $Q_K$ spaces, Springer, 2017. https://doi.org/10.1007/978-3-319-58287-0 |
| [20] | J. Xiao, Holomorphic $Q$ classes, Lecture Notes in Mathematics, Springer Berlin, 2001. https://doi.org/10.1007/b87877 |