Trace formulas for Schr\"odinger operators with complex potentials on half-line

Abstract

We consider Schr\"odinger operators with complex-valued decreasing potentials on the half-line. Such operator has essential spectrum on the half-line plus eigenvalues (counted with algebraic multiplicity) in the complex plane without the positive half-line. We determine trace formula: sum of Im part of these eigenvalues plus some singular measure plus some integral from the Jost function. Moreover, we estimate of sum of Im part of eigenvalues and singular measure in terms of the norm of potentials. In addition, we get bounds on the total number of eigenvalues, when the potential is compactly supported.