O Functional Quantum Mechanics and the Equivalence with a Product of Schrödinger Problems
F. Wahl, W. Feist · Zeitschrift für Naturforschung A · 1981
Abstract The New Tamm-Dancoff procedure consists of three main parts: an expansion for pairs of states with respect to a non-orthogonal base, a cut-off approximation for this expansion, and a transformation with respect to a new reference state. In this paper we treat part one and two. It is shown that the NTD-procedure is equivalent to the tensor product of the original Schrödinger problem and its conjugate problem. The occurring nonlinear transformation is examined and the cut-off is discussed.