An example of a complete orthonormal system in a Hilbert space of generalized functions
We construct a complete orthonormal system of generalized functions in a Hilbert space W −1. We obtain an estimate of the error of approximation in W −1, which is expressed in terms of the integral modulus of continuity of a function from L 2.
English version (Springer): Ukrainian Mathematical Journal 49 (1997), no. 5, pp 812-815.
Citation Example: Gladkivs’ka O. V. An example of a complete orthonormal system in a Hilbert space of generalized functions // Ukr. Mat. Zh. - 1997. - 49, № 5. - pp. 725–728.