Entropy and the link action in the causal set path-sum

Abstract

In causal set theory the gravitational path integral is replaced by a path-sum over a sample space Ω n of n-element causal sets. The contribution from non-manifold-like orders dominates Ω n for large n and therefore must be tamed by a suitable action in the low energy limit of the theory. We extend the work of Loomis and Carlip on the contribution of sub-dominant bilayer orders to the causal set path-sum and show that the ‘link action’ suppresses the dominant Kleitman–Rothschild orders for the same range of parameters.