Hacettepe Journal of Mathematics and Statistics, cilt.51, sa.6, ss.1577-1587, 2022 (SCI-Expanded)
Basis properties of exponential and trigonometric systems in grand Lebesgue spaces Lp)(−π, π) are studied. Based on a shift operator, we consider the subspace Gp)(−π, π) of the space Lp)(−π, π), where continuous functions are dense, and the boundedness of the singular operator in this subspace is proved. We establish the basicity of exponential system {eint}n∈Z for Gp)(−π, π) and the basicity of trigonometric systems {sin nt}n∈N and {cos nt}n∈N0 for Gp)(0, π).