English

Baire categories and classes of analytic functions in which the Wiman-Valiron type inequality can be almost surely improved

Complex Variables 2012-06-19 v1

Abstract

Let f(z)=n=0+anznf(z)=\sum_{n=0}^{+\infty} a_nz^n\ (zC)(z\in\mathbb{C})\ be an analytic function in the unit disk and ftf_t be an analytic function of the form ft(z)=n=0+aneiθntzn,f_t(z)=\sum_{n=0}^{+\infty} a_ne^{i\theta_nt}z^n, where tR,t\in\mathbb{R}, θnN,\theta_n\in\mathbb{N}, and hh be a positive continuous function on (0,1)(0, 1) increasing to ++\infty and such that r01h(r)dr=+,r0(0,1). \int_{r_0}^1h(r)dr=+\infty, r_0\in(0,1).\ If the sequence (θn)n0(\theta_n)_{n\geq0} satisfies the inequality limn+1lnnlnθnθn+1θnδ[0,1/2), \varlimsup_{n\to+\infty}\frac1{\ln n}\ln\frac{\theta_n}{\theta_{n+1}-\theta_n}\leq\delta\in[0,1/2), then for all analytic functions ftf_t almost surely for tt there exists a set E=E(δ,t)(0,1)E=E(\delta,t)\subset(0,1) such that Eh(r)dr<+\int_Eh(r)dr<+\infty and limsubstackr10rEsubstacklnMf(r,t)lnμf(r)2lnh(r)+lnln{h(r)μf(r)}1+2δ4+3δ, \varlimsup_{{substack} {r\to1-0 r\notin E}{substack}} \frac{\ln M_f(r,t)-\ln\mu_f(r)}{2\ln h(r)+\ln\ln\{h(r)\mu_f(r)\}}\leq\frac{1+2\delta}{4+3\delta}, where Mf(r,t)=max{ft(z) ⁣:z=r},M_f(r,t)=\max\{|f_t(z)|\colon |z|=r\},\ μf(r)=max{anrn ⁣:n0}\mu_f(r)=\max\{|a_n|r^n\colon n\geq 0\}\ for r[0,1).r\in[0, 1).

Keywords

Cite

@article{arxiv.1206.3655,
  title  = {Baire categories and classes of analytic functions in which the Wiman-Valiron type inequality can be almost surely improved},
  author = {A. O. Kuryliak and O. B. Skaskiv and I. E. Chyzhykov},
  journal= {arXiv preprint arXiv:1206.3655},
  year   = {2012}
}

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17 pages