Trace Formulas for Schrödinger Operators with Complex Potentials
We consider 3-dimensonal Schr¨odinger operators with complex potential. We
obtain new trace formulas with new terms, associated with singular measure. In order to
prove these results, we study analytic properties of a modified Fredholm determinant as a
function from Hardy spaces in the upper half-plane. In fact, we reformulate spectral theory
problems as problems of analytic functions from Hardy spaces.