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On the completeness of the system \(\{t^{\lambda _{n}}\log ^{m_{n}}t\}\) in \(C_{0}(E)\). (English) Zbl 1265.30177

Summary: Let \(E=\bigcup _{n=1}^{\infty }I_{n}\) be the union of infinitely many disjoint closed intervals, where \(I_{n}=[a_{n}\), \(b_{n}]\), \(0<a_{1}<b_{1}<a_{2}<b_{2}<\dots <b_{n}<\dots \), \(\lim _{n\rightarrow \infty }b_{n}=\infty\). Let \(\alpha (t)\) be a nonnegative function and \(\{\lambda _{n}\}_{n=1}^{\infty }\) a sequence of distinct complex numbers. In this paper, a theorem on the completeness of the system \(\{t^{\lambda _{n}}\log ^{m_{n}}t\}\) in \(C_{0}(E)\) is obtained, where \(C_{0}(E)\) is the weighted Banach space consisting of complex functions continuous on \(E\) with \(f(t)\text{e}^{-\alpha (t)}\) vanishing at infinity.

MSC:

30E10 Approximation in the complex plane
41A10 Approximation by polynomials
Full Text: DOI

References:

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