On a Sum Rule for Schrödinger Operators with Complex Potentials

where the constant C depends on t, γ and d (see also [6] for the case when V is real). The paper [5] deals with the natural question that appears in relation to the main result of [3]: what estimates are valid for the eigenvalues situated inside the conical sector {λ : |Iλ| < tRλ}, where the eigenvalues might be close to the positive half-line? Theorems of the article [5] provide some information about the rate of accumulation of eigenvalues to the set R+ = [0,∞). Namely, [5] gives sufficient conditions on V that guarantee convergence of the sum