Abstract
In this note it is proved that if a complete orthonormal system {ϕ n} in L2[0, 1] contains a subsystem {ϕ nk} of a lacunary order p>2, then for some bounded measurable function h(x) the system {h(x)ϕ n(x)}n≠nk is complete in L2[0, 1].
Similar content being viewed by others
Literature cited
R. P. Boas and H. Pollard, “The multiplicative completion of sets of functions,” Bull. Amer. Math. Soc.,54, 518–522 (1948).
A. A. Talalyan, “Representation of measurable functions by series,” Usp. Matem. Nauk,15, No. 5, 77–141 (1960).
N. K. Bari, Trigonometrical Series [in Russian], Fizmatgiz, Moscow (1961).
Author information
Authors and Affiliations
Additional information
Translated from Matematicheskie Zametki, Vol. 18, No. 6, pp. 815–824, December, 1975.
In conclusion the author thanks E. M. Nikishin for useful discussions regarding this note.
Rights and permissions
About this article
Cite this article
Pogosyan, N.B. Systems of functions which are complete in measure. Mathematical Notes of the Academy of Sciences of the USSR 18, 1075–1080 (1975). https://doi.org/10.1007/BF01099984
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01099984