ABSOLUTE CONVERGENCE OF FOURIER SERIES OVER COMPLETE ORTHONORMAL SYSTEMS OF FUNCTIONS
S V Bočkarev · Mathematics of the USSR-Sbornik · 1971
In the paper results of the type of the Bernstein-Saks theorem and Carleman's singularity are established for arbitrary complete orthonormal systems, as well as for any countable family of such systems. The method of proof is based on utilizing series with random arrangement of signs.Bibliography: 5 titles.