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# One remark about the unconditional exponential bases and cosine bases, connected with them

### Abstract

In the paper we consider examples of basis families $\{\cos \lambda_k t\}^\infty_1$, $\lambda_k>0$, in the space $L_2(0,\sigma)$, such that systems $\{e^{i\lambda_kt},e^{-i\lambda_kt}\}^\infty_1$ don't form an unconditional basis in space $L_2(-\sigma,\sigma)$.

### Article Information

 Title One remark about the unconditional exponential bases and cosine bases, connected with them Source Methods Funct. Anal. Topology, Vol. 14 (2008), no. 4, 330-333 MathSciNet MR2469072 Copyright The Author(s) 2008 (CC BY-SA)

### Authors Information

G. M. Gubreev
Poltava National Technical University, 24 Pervomaiskii prospect, Poltava, 36011, Ukraine

M. G. Volkova
South-Ukrainian Pedagogical University, Odessa, Ukraine

### Citation Example

G. M. Gubreev and M. G. Volkova, One remark about the unconditional exponential bases and cosine bases, connected with them, Methods Funct. Anal. Topology 14 (2008), no. 4, 330-333.

### BibTex

@article {MFAT482,
AUTHOR = {Gubreev, G. M. and Volkova, M. G.},
TITLE = {One remark about the unconditional exponential bases and cosine bases, connected with them},
JOURNAL = {Methods Funct. Anal. Topology},
FJOURNAL = {Methods of Functional Analysis and Topology},
VOLUME = {14},
YEAR = {2008},
NUMBER = {4},
PAGES = {330-333},
ISSN = {1029-3531},
URL = {http://mfat.imath.kiev.ua/article/?id=482},
}