On the Polya type of an entire function
Автор: Malyutin K.G.
Журнал: Владикавказский математический журнал @vmj-ru
Статья в выпуске: 1 т.27, 2025 года.
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Let f be an entire function and let M(r,f)=max|z|=r|f(z)| be maximum of the modulus of the function f in disk |z|≤r. The article considers the density functions of the maximum modulus of the function f, which are calculated using the formulas M(α)=lim¯¯¯¯¯¯¯r→∞M(r+αr,f)-M(r,f)rρ(r),M--(α)=lim---r→∞M(r+αr,f)-M(r,f)rρ(r),α≥0, where ρ(r) is proximate order in the sense of Valiron, limr→+∞ρ(r)=ϱ≥0. It is proved, that M(α) and M--(α) are ϱ-semi-additive functions. The definition of the type σp(f) and the minimum type σ--p(f) in the sense of Polia of the function f is introduced by the formulas σp(f)=limα→+0M(α)α,σ--p(f)=limα→+0M--(α)α. These quantities give more information about the behavior of the function than its type and lower type in the classical sense. This definition is an extension of the concepts of maximum and minimum density of a sequence of positive numbers introduced by Polya, who proved their existence if the growth of the counting function of a sequence of numbers has normal type with respect to r. The existence of the quantities σp(f) and σ--p(f) is proved if the growth ln|f| has type not higher than normal type with respect to rρ(r) in the classical sense, i. e. lnM(r,f)≤Krρ(r) for some K>0. Some properties of functions M(α) and M--(α) are considered.
Entire function, density function, semi-additive function, polya theorem, maximum type, minimum type
Короткий адрес: https://sciup.org/143184106
IDR: 143184106 | DOI: 10.46698/k4349-9424-9818-w