
doi: 10.4064/sm145-2-2
Having no answer to the question of J.Zemánek who asked whether there are quasinilpotent operators \(Q\) such that \(A=I+Q\) would satisfy the Ritt resolvent conditions, i.e. \[ \|(\lambda I-A)^{-1}\|{c\over |\lambda-1|} \quad \text{for } |\lambda|>1, \] the author proves that this condition is equivalent to the following one: there exist constants \(M_0\) and \(M_1\) such that for all natural \(n\) \[ \|A^n \|\leq M_0 \] and \[ \|A^n(A-I)\|\leq{M_1\over{n+1}}. \] The author discusses other relations between the growth of the resolvent near the unite circle and bounds for the powers of the operator.
bounded characteristics, Kreiss resolvent condition, Other generalizations of analytic functions (including abstract-valued functions), quasinilpotent operators, Symbolic dynamics, Ritt resolvent condition, Spectrum, resolvent
bounded characteristics, Kreiss resolvent condition, Other generalizations of analytic functions (including abstract-valued functions), quasinilpotent operators, Symbolic dynamics, Ritt resolvent condition, Spectrum, resolvent
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