We demonstrate that the cut which is present as the leading singularity in the two-point function of the Ising field theory for $T<T_c$ and $H=0$ breaks up into a sequence of poles for $H\ne 0$. Both the positions and the residues of the low-lying poles are calculated.

• Received 12 April 1978

DOI:https://doi.org/10.1103/PhysRevD.18.1259