For Schrödinger operators (including those with magnetic fields) with singular scalar potentials on manifolds of bounded geometry, we study continuity properties of some related integral kernels: the heat kernel, the Green function, and also kernels of some other functions of the operator. In particular, we show the joint continuity of the heat kernel and the continuity of the Green function outside the diagonal. The proof makes intensive use of the Lippmann-Schwinger equation.
IntroductionThe analysis of Schrödinger operators occupies a central place in quantum mechanics. Suitably normalized, over the configuration space R n these operators have the formwhere A is the magnetic vector potential and U is an electric potential. A huge literature is dedicated to the study of properties of H A,U in its dependence on A and U , see the recent reviews [48,54,55]. An essential feature of the quantummechanical operators in comparision to the differential operator theory is admitting singular potentials [19], although the operator itself preserves some properties like regularity of solutions [29].