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Постійне посилання на розділhttps://dspace.nuft.edu.ua/handle/123456789/7372

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  • Ескіз
    Документ
    Properties of solutions of a heterogeneous differential equation of the second order
    (2019) Mulyava, Oksana; Sheremeta, Miroslav; Trukhan, Yu. S.
    Suppose that a power seriesA(z) =∑∞n=0anznhas the radius of convergenceR[A]∈[1,+∞].For a heterogeneous differential equationz2w′′+ (β0z2+β1z)w′+ (γ0z2+γ1z+γ2)w=A(z)with complex parameters geometrical properties of its solutions (convexity, starlikeness and close-to-convexity) in the unit disk are investigated. Two cases are considered: ifγ26=0 andγ2=0. Wealso consider cases when parameters of the equation are realnumbers. Also we prove that for asolutionfof this equation the radius of convergenceR[f]equals toR[A]and the recurrent formulasfor the coefficients of the power series off(z)are found. For entire solutions it is proved that theorder of a solutionfis not less then the order ofA(̺[f]≥̺[A]) and the estimate is sharp. The sameinequality holds for generalized orders (̺αβ[f]≥̺αβ[A]). For entire solutions of this equation thebelonging to convergence classes is studied. Finally, we consider a linear differential equation of theendless order∞∑n=0ann!w(n)=Φ(z), and study a possible growth of its solutions.
  • Ескіз
    Документ
    On Hadamard compositions of Dirihlet series and Dirihlet series absolutely converging in half-plane
    (2019) Mulyava, Oksana; Sheremeta, Miroslav
    In terms of generalized orders the growth of this composition and their derivatives is investigated. A relation between the behavior of the maximal terms of the Hadamard composition of the derivatives and of the derivative of the Hadamard composition is established.
  • Ескіз
    Документ
    Remarks to relative growth of entire dirichlet series
    (2019) Mulyava, Oksana; Sheremeta, Miroslav
    The growth of F with respect to G is studied through the generalized order. Formulas are found for the finding these quantities.
  • Ескіз
    Документ
    On Hadamard composition of Gelfond-Leont’ev derivatives of entire and analytic functions in the unit disk
    (2021) Mulyava, Oksana; Sheremeta, Miroslav
    For an entire function and an analytic in the unit disk function the growth of the Hadamard composition of their Gelfond-Leont'ev derivatives is investigated in terms of generalized orders. A relationship between the behaviors of the maximal terms of Hadamard composition of Gelfond-Leont'ev derivatives and of the Gelfond-Leont'ev derivative of Hadamard composition is established.
  • Ескіз
    Документ
    On the Relative Growth of Dirichlet Series with Zero Abscissa of Absolute Convergence
    (2021) Mulyava, Oksana
    Let F and G be analytic functions given by Dirichlet series with exponents increasing to + ∞ and zero abscissa of absolute convergence.The growth of F with respect to G is studied through the generalized order. Formulas are found for the finding these quantities.
  • Ескіз
    Документ
    On belonging of characteristic functions of probability laws to a convergence class
    (2013) Kulyavetc, Lubov; Mulyava, Oksana; Sheremeta, Miroslav
    It is investigated the condition on a probability law, under which its characteristic function belongs to a convergence class. Досліджено умову на ймовірнісний закон відповідно до якого характеристична функція належить до класу збіжності.
  • Ескіз
    Документ
    Relation between the maximum modulus and the maximal term of Dirichlet series in terms of a convergence class
    (2012) Mulyava, Oksana; Sheremeta, Miroslav; Sumyk, O.
    A relation between the growth of maximum modulus and the growth maximal term of Dirichlet series in terms of a convergence class is investigated.Досліджено зв’язок між зростанням максимуму модуля і зростанням максимального члена ряду Діріхле в термінах класів збіжності.
  • Ескіз
    Документ
    On a convergence class for Dirichlet series
    (2000) Mulyava, Oksana; Sheremeta, Miroslav
    A relation between the maximum of the modulus, the maximal term and coefficients of Dirichlet series in terms of a convergence class is investigated. Досліджено зв’язок між максимумом модуля, максимальним членом і коефіцієнтами ряду Діріхле в термінах класів збіжності.
  • Ескіз
    Документ
    On belonging of Naftalevich-Tsuji products to a generalized convergence class
    (2002) Gal, Yuriy; Mulyava, Oksana; Sheremeta, Miroslav
    In terms of the zeros distribution, a class of Naftalevich-Tsuji products defined by the convergence of the integral is described, where and are positive continuous increasing to functions. В термінах розподілу нулів описаний клас добутків Нафталевича-Цудзі, визначений збіжністю інтеграла, де і – додатні неперервні зростаючі до функції.
  • Ескіз
    Документ
    A convergence class for entire Dirichlet series of slow growth
    (2000) Mulyava, Oksana
    For an entire Dirichlet series with nonnegative increasing to infinity exponents a connection between the growth of maximum modulus and the behavior of coefficients is established in the terms of certain convergence class.