Author/Authors :
Ashurov، Ravshan نويسنده Institute of Advanced Technology (ITMA),Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia , , Ahmedov، Anvarjon نويسنده Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor ,
Abstract :
In this paper we consider spectral expansions of functions from Nikolʹskii classes related to selfadjoint extensions of elliptic differential operators of order in We construct a continuous function from Nikolʹskii class with such that the Riesz means of spectral expansion of which diverge at the origin. This result demonstrates sharpness of the condition obtained earlier by Alimov (1976) for uniform convergence of spectral expansions, related to elliptic differential operators.
