  Energetic causal sets are causal sets endowed by a flow of energy-momentum
between causally related events. These incorporate a novel mechanism for the
emergence of space-time from causal relations. Here we construct a spin foam
model which is also an energetic causal set model. This model is closely
related to the model introduced in parallel by Wolfgang Wieland in
arXiv:1407.0025, and this construction makes use of results used there. What
makes a spin foam model also an energetic causal set is Wieland's
identification of new momenta, conserved at events (or four-simplices), whose
norms are not mass, but the volume of tetrahedra. This realizes the torsion
constraints, which are missing in previous spin foam models, and are needed to
relate the connection dynamics to those of the metric, as in general
relativity. This identification makes it possible to apply the new mechanism
for the emergence of space-time to a spin foam model.
