IJPAM: Volume 25, No. 1 (2005)
Faculty of Mathematical Sciences
University of Tabriz
Abstract.In this paper we consider the shift operator on Hilbert spaces and by using this operator we define the modulus of continuity of fractional index, including relation to the -functional and we prove the fractional analog we direct and inverse theorems of approximation theory.
Received: August 10, 2005
AMS Subject Classification: 42C10, 43A77, 43A90
Key Words and Phrases: Hilbert space, self-adjoint operator, -functional
Source: International Journal of Pure and Applied Mathematics