Bound States in the 3d Ising and Φ~4 Models

摘要

We discuss the spectrum of the three dimensional Ising model and Φ~4 field theory in the broken symmetry phase. In this phase the effective potential between the elementary quanta is attractive and bound states of two or more of them may exist. We give theoretical and numerical evidence for the existence of these bound states. Looking in particular at the Ising model we discuss, by means of low temperature expansion techniques, the general pattern of the bound states spectrum.