The Steinhaus theorem on equiconvergence for functional-differential operators
M. Sh. Burlutskaya, Avgust Petrovich Khromov · Mathematical Notes · 2011
We establish the equiconvergence of the series S ( af ) and a ( x ) S ( f ), where S ( f ) is the Fourier series in the eigenfunctions and associated functions of a certain functional-differential operator with involution.