March 11, 2020

Answered by: Jonathan Gorard

What do your models imply regarding dark energy and the cosmological constant?

Our derivation of general relativity in the continuum limit of Wolfram model systems that satisfy causal invariance and asymptotic dimensionality preservation defines the Einstein field equations only up to an integration constant, thus implying that the model is compatible with both zero and non-zero values of the cosmological constant. Since the energy-momentum tensor for a Wolfram model evolution corresponds to a measure of the flux of causal edges through certain discrete hypersurfaces in the causal graph, we can conclude that those causal edges that are associated with the evolution of elementary particles (such as, for instance, causal edges corresponding to the evolution of nonplanar regions of the spatial hypergraph) will correspond to standard (baryonic) matter contributions, and all remaining causal edges, that are simply associated with the evolution of the background hypergraph, will correspond to vacuum energy contributions. As the latter quantity may vary dynamically as a function of position within the causal graph, we can conclude that the Wolfram model is also compatible with dynamical scalar field models of dark energy, such as quintessence and moduli fields.