Inequalities for the Fourier coefficients in unbounded orthogonal systems in generalized Lorentz spaces

  • Gabdolla Akishev L.N.Gumilyov Eurasian National University, Satbaev Street 2, Nur-Sultan, 010008, Republic Kazakhstan
  • Lars--Erik Persson UIT The Arctic University of Norway, Karlstad University, Sweden.
  • Harpal Singh UIT The Arctic University of Norway, Narvik, Norway.


This paper is an essential complement of the research recently presented in [1], [2]. A number of classical Fourier inequalities related to Fourier coefficients with respect to unbounded orthogonal systems are generalized and complemented. All results are given in the case of generalized
Lorentz spaces.