The growth of Dirichlet series

We define Knopp-Kojima maximum modulus and the Knopp-Kojima maximum term of Dirichlet series on the right half plane by the method of Knopp-Kojima, and discuss the relation between them. Then we discuss the relation between the Knopp-Kojima coefficients of Dirichlet series and its Knopp-Kojima order defined by Knopp-Kojima maximum modulus. Finally, using the above results, we obtain a relation between the coefficients of the Dirichlet series and its Ritt order. This improves one of Yu Jia-Rong’s results, published in Acta Mathematica Sinica 21 (1978), 97–118. We also give two examples to show that the condition under which the main result holds can not be weakened.     

Growth of horizontal rays of analytic functions represented by Dirichlet series

The question is investigated of the coincidence on a ray and in a half-plane of generalized orders of growth of analytic functions represented by Dirichlet series absolutely convergent in the half-plane.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 3, pp. 363–371, March, 1990.     

Convergence and growth of multiple Dirichlet series

This article investigates the convergence and growth of multiple Dirichlet series. The Valiron formula of Dirichlet series is extended to n-tuple Dirichlet series and an equivalence relation between the order of n-tuple Dirichlet series and its coefficients and exponents is obtained.     

Chromatic series for functions of slow growth

The theory of chromatic derivatives leads to chromatic series which replace Taylor's series for bandlimited functions. For such functions, these series have a global convergence property not shared by Taylor's series. In this work the theory is extended to bandlimited functions of slow growth. This includes many signals of practical importance such as polynomials, periodic functions and almost periodic functions. This extension also enables us to get improved local convergence results for chromatic series.     

Behavior on the real line of entire functions represented by Dirichlet series

Conditions are found under which for an entire function f represented by a Dirichlet series with finite Ritt order on some sequence (x_k), 0 < x_k , as k one has ¦f(x_k)¦=M_t((1 + 0(1) x_k), M_f(x)=sup {¦ f (z) ¦:Re z x}.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 2, pp. 265–269, February, 1991.     

Estimation on curves of Dirichlet series with a convex growth majorant

For a class of Dirichlet series defined by a certain convex growth majorant we establish conditions for a sequence of indices which provide the implementation of precise estimates for their increase and decrease on curves that tend to infinity in a special way.     

On the growth of analytic functions represented by the Dirichlet series on semistrips

The behavior of the Dirichlet series with null abscissa of absolute convergence is studied on semistrips.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 45, No. 5, pp. 681–693, May, 1993.     

Behavior of maximum term of a multiple Dirichlet series defining an entire function

Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 8, pp. 1047–1053, August, 1989.     

Behavior on the real line of entire functions represented by Dirichlet series with complex exponents

It is shown, in particular, that if _{n k} when n k, Re _n > 0, and , then an entire function F that is bounded on the real line and represented by a Dirichlet series d_n exp (_nz) that is uniformly and absolutely convergent on each compactum in is identically zero.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 7, pp. 882–888, July, 1990.     

Dirichlet series of Rankin-Cohen brackets

Given modular forms f and g of weights k and ?, respectively, their Rankin-Cohen bracket corresponding to a nonnegative integer n is a modular form of weight k+?+2n, and it is given as a linear combination of the products of the form f(r)g(n−r) for 0?r?n. We use a correspondence between quasimodular forms and sequences of modular forms to express the Dirichlet series of a product of derivatives of modular forms as a linear combination of the Dirichlet series of Rankin-Cohen brackets.     

A class of Dirichlet series

Two theorems are proved on Dirichlet series of a special type related to multiplicative functions f(n), ¦f(n)¦1. These theorems develop well-known results of Halász (G. Halász, Acta Math. Acad. Sci. Hungar.,19, Nos. 3–4, 365#x2013;404 (1968)).Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 50, pp. 187–194, 1975.