UKRAINIAN MATHEMATICAL JOURNAL, cilt.70, sa.7, ss.1052-1062, 2018 (SCI-Expanded)
The generalized difference operator.a, b was defined by El- Shabrawy:.a, bx =.a, b ( xn) = ( anxn + bn- 1xn- 1) 1n = 0 with x- 1 = b- 1 = 0, where ( ak) and ( bk) are convergent sequences of nonzero real numbers satisfying certain conditions. We completely determine the approximate point spectrum, the defect spectrum, and the compression spectrum of the operator.a, b in a sequence space c0.