Fig. 5: Basic ingredients of the perturbative field theory in 1/M for Ba2FeSi2O7.
From: Decay and renormalization of a longitudinal mode in a quasi-two-dimensional antiferromagnet
Solid (dash) lines represent the bare propagator of the transverse (longitudinal) boson. The symmetry-allowed cubic vertices are shown on the second and third lines. The red (blue) dot represents a decay (sink) vertex. The cubic–linear vertices are listed on the fourth line. The last line represents the normal vertex \({V}_{\alpha \alpha }^{(4,N)}\) from \({{{{{{\mathcal{H}}}}}}}^{(4)}\).
