Abstract
We study the completeness of the system of exponents exp(−λ n t), Re λ n > 0, in spaces L p with the power weight on the semiaxis ℝ+. We prove a sufficient condition for the completeness; one can treat it as a modification of the well-known Szász condition. With p = 2 it is unimprovable (in a sense). The proof is based on the results (which are also obtained in this paper) on the distribution of zeroes of functions of the Bergman classes in a half-plane.
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References
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Dedicated to the memory of Petr Lavrent’evich Ul’yanov on the occasion of his 80th anniversary
Original Russian Text © A.M. Sedletskii, 2008, published in Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika, 2008, No. 5, pp. 92–100.
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Sedletskii, A.M. Approximation of the Müntz-Szász type in weight spaces L p and zeroes of functions of Bergman classes in a half-plane. Russ Math. 52, 80–87 (2008). https://doi.org/10.3103/S1066369X08050101
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DOI: https://doi.org/10.3103/S1066369X08050101