We examine the possibility of inferring energy spectra and their concomitant eigenstates on the basis of incomplete information concerning the system’s ground state. In addition, the possibility of considering, as prior information, the expectation values of a partially unknown Hamiltonian also is examined and shown to be feasible.

• Received 12 July 1990

DOI:https://doi.org/10.1103/PhysRevA.43.1145