Gubreev G. M.
Ukr. Mat. Zh. - 2013. - 65, № 5. - pp. 706–711
We study the spectral properties of linear combinations of the Volterra dissipative operator and its adjoint operator in a separable Hilbert space.
Ukr. Mat. Zh. - 1992. - 44, № 8. - pp. 1031–1044
We describe complete minimal families of exponential functions and Riesz bases of exponential functions which admit orthogonalizers of a special type. We obtain a complete description of all orthogonalizers of the class of complete minimal family of exponential functions under consideration and formulate a simple condition which guarantees the uniqueness of the orthogonalizer.
Ukr. Mat. Zh. - 1981. - 33, № 4. - pp. 518–521