A construction of complete minimal,but not uniformly minimal,exponential systems with real separable spectrum inL p andC

We construct real separable sequences { _n } such that the corresponding systems of exponentials exp(i _n t) are complete and minimal, but not uniformly minimal, in the spacesL ^p (–, ), 1p<, orC[–, ].Translated fromMatematicheskie Zametki, Vol. 58, No. 4, pp. 582–595, October, 1995.The work was supported by the Russian Foundation for Basic Research under grant No. 93-011-205     

Excesses of systems of exponential functions

Conditions on the closeness of real sequences {_n} and {_n} are studied which imply the equality of the excesses of the systems {exp(i_nx)} and {exp(i_nx)} in the space L²(–a, a). A theorem is formulated in terms of the difference of the sequences {_n} and {_n} enumerating the functions. In the corollaries of the theorem, conditions are given in terms of the behavior of the difference _n–_n0. An example is constructed showing that the condition _n–_n0 alone is not sufficient for equality of the excesses.Translated from Matematicheskie Zametki, Vol. 22, No. 6, pp. 803–814, December, 1977.     

On Zeros of Functions of Mittag--Leffler Type

As is well known, the asymptotics of zeros of functions of Mittag--Leffler type $$E_\rho \left( {z;\mu } \right) = \sum\limits_{n = 0}^\infty {\frac{{z^n }}{{\Gamma \left( {\mu + {n \mathord{\left/ {\vphantom {n \rho }} \right. \kern-\nulldelimiterspace} \rho }} \right)}}} ,{\text{ }}\rho >0,{\text{ }}\mu \in \mathbb{C},$$ describes the behavior of zeros outside a disk of sufficiently large radius. In the paper we solve the problem of finding the number of zeros inside such a disk; this allows us to indicate the numeration of all zeros $E_\rho \left( {z;\mu } \right)$ that agrees with the asymptotics. We study the problem of the distribution of zeros of two functions that can be expressed in terms of $E_1 \left( {z;\mu } \right)$ , namely of the incomplete gamma-function and of the error function.     

Rate of decrease of eigenvalues of a Fredholm operator

Moscow. Translated from Sibirskii Matematicheskii Zhurnal, Vol. 31, No. 5, pp. 120–127, September–October, 1990.     

Asymptotic behavior of zeros of Mittag-Leffler functions of order 1/2

Let z _n denote the sequence of zeros of the Mittag-Leffler function E _ρ (z; μ), ρ > 0, μ ∈ ?, which is an entire function of order ρ. With the exception of the case ρ = 1/2, Re μ = 3 an asymptotic behavior of the sequence z _n ^ρ was known earlier up to infinitesimals o(1) having a sharply defined rate of decrease. In this paper the behavior of the sequence z _n ^1/2 is studied just in this exceptional case. Furthermore, for ρ = 1/2, μ > 3 we give the form of a curvilinear half-plane which is free of the points z _n .     

Bases of exponentials,sines, and cosines in weighted spaces on a finite interval

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