Completeness of the exponential system on a segment of the real axis
Eurasian mathematical journal, Tome 13 (2022) no. 2, pp. 37-42.

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Let $\Lambda=\{\lambda_n\}$ be the sequence of all zeros of the entire function $\Delta(\lambda)=1-i\lambda\int_0^1f(t)e^{i\lambda t}dt$ of exponential type. We consider exponential system of functions $e(\Lambda)=\{t^{p-1}e^{i\lambda_nt}, 1\leqslant p\leqslant m_n\}$, where $m_n$ — is the multiplicity of the zero $\lambda_n$. The question is: for which $a$$b$ ($a$) is the system $e(\Lambda)$ complete (incomplete) in the space $L^2(a, b)$? Let $D$ be the length of the indicator conjugate diagram of the entire function $\Delta(\lambda)$. Then the following statements are valid: when $b-a>D$ the system $e(\Lambda)$ is incomplete in $L^2(a,b)$; when $b-a$ the system $e(\Lambda)$ is complete in $L^2(a,b)$; if we remove from $\Lambda$ any two points $\lambda$ and $\mu$, then the system $e(\Omega)$, $\Omega=\Lambda\setminus\{\lambda,\mu\}$ is incomplete in $L^2(a,b)$ also when $b-a=D$.
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A. M. Gaisin; B. E. Kanguzhin; A. A. Seitova. Completeness of the exponential system on a segment of the real axis. Eurasian mathematical journal, Tome 13 (2022) no. 2, pp. 37-42. http://geodesic.mathdoc.fr/item/EMJ_2022_13_2_a2/

[1] N. F. Abuzyarova, “On properties of functions invertible in the sense of Ehrenpreis in the Schwartz algebra”, Eurasian Math. J., 13:1 (2022), 9–18 | DOI | MR | Zbl

[2] A. Beurling, P. Malliavin, “On Fourier transforms of measures with compact support”, Acta Mathematica, 107:3-4 (1962), 291–309 | DOI | MR | Zbl

[3] B. N. Khabibullin, “Zero sequences of holomorphic functions, representation of meromorphic functions. II. Entire functions”, Matematicheskii Sbornik, 200:2 (2009), 283–312 (in Russian) | DOI | MR | Zbl

[4] A. N. Kolmogorov, S. V. Fomin, Elements of the theory of functions and functional analysis, Nauka, M., 1976 (in Russian) | MR

[5] I. F. Krasichkov-Ternovskii, “Interpretation of the Beurling Malliavin theorem on the radius of completeness”, Matematicheskii Sbornik, 180:3 (1989), 397–423 (in Russian) | MR | Zbl

[6] A. F. Leont'ev, Exponential series, Nauka, M., 1976 (in Russian) | MR | Zbl

[7] E. M. Nikishin, V. N. Sorokin, Rational approximations and orthogonality, Nauka, M., 1988 (in Russian) | MR | Zbl