EN
For a bounded and sectorial linear operator V in a Banach space, with spectrum in the open unit disc, we study the operator $Ṽ = ∫_{0}^{∞} dα V^{α}$. We show, for example, that Ṽ is sectorial, and asymptotically of type 0. If V has single-point spectrum {0}, then Ṽ is of type 0 with a single-point spectrum, and the operator I-Ṽ satisfies the Ritt resolvent condition. These results generalize an example of Lyubich, who studied the case where V is a classical Volterra operator.