Conditions for convergence and summability of spectral decompositions meeting elliptic operators

Investigated have been multiple Fourier series. The work has been aimed at analyzing conditions of uniform convergence of spectral decomposition of a singular elliptic operator and conditions for uniform convergence for triangular partial sums of Fourier double series. Found have been conditions for uniform convergence and localization of correspondent spectral decompositions. In addition to this, found have been final conditions for uniform convergence in Nikolsky classes, triangular partial double trigonometric Fourier series. The area of usage: mathematical physics problems, the theory of differential equationsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio