A new approach to spectrum calculations in lattice Hamiltonian field theories. 1. Introduction and application to lambda phi4 in (1+1) dimensions

A finite lattice technique is introduced for calculating the spectrum of fluctuating Bose theories in the continuum limit. The method gives the continuum spectrum to an estimated approximately 1% accuracy in (1+1) dimensions using available computer memory. The spectrum of lambda phi4 theory in (1+1) dimensions is studied as a trial application; results are found consistent with a free theory spectrum. (author)