A LIMITING ABSORPTION PRINCIPLE FOR SCHRODINGER-OPERATORS WITH GENERALIZED VON-NEUMANN-WIGNER POTENTIALS .1. CONSTRUCTION OF APPROXIMATE PHASE

In this series of papers we prove the limiting absorption principle ov er a given interval for a class of Hamiltonians which contains the ori ginal one of von Neumann and Wigner. More specifically, the Hamiltonia ns are of the form -Delta + c sin b\x\/\x\(beta) + V(x), where 2/3 < b eta less than or equal to 1, V(x) is a short range potential and J is a given compact subinterval of the open positive axis which does not c ontain the point b(2)/4. (C) 1997 Academic Press.