Boundedness properties of resolvents and semigroups of operators

J. van Casteren
1997 Banach Center Publications  
Let T : H → H be an operator in the complex Hilbert space H. Suppose that T is square bounded in average in the sense that there exists a constant M (T ) with the property that, for all natural numbers n and for all x ∈ H, the inequality 1 n + 1 n j=0
doi:10.4064/-38-1-59-74 fatcat:qnoxabsqyzdifnu7qg5ag3neha