Izvestiya of Saratov University.

Mathematics. Mechanics. Informatics

ISSN 1816-9791 (Print)

ISSN 2541-9005 (Online)

root functions

Estimation of the difference of partial sums of expansions by the root functions of the differential operator and into trigonometric Fourier series

On Multiple Completeness of the Root Functions of a Certain Class of Pencils of Differential Operators with Constant Coefficients

On Multiple Completeness of the Root Functions of the Pencils of Differential Operators with Constant Coefficients

Multiple Completeness of the Root Functions of the Pencils of Differential Operators with Constant Coefficients and Splitting Boundary Conditions