On the material origin of the cosmological constant
  We consider a possible connection between matter and cosmological constant $\Lambda$ via the Newtonian cosmic potential of the matter within the expanding particle horizon. Consistent with GR, an increasing potential may drive the metric expansion of space. Cosmic recession of mass must, in turn, affect the potential in an opposite sense. Independent of this, several considerations point at $-\tfrac{1}{2}c^{2}$ as the representation of the background potential in the various GR metrics. This suggests that the cosmic potential, while subject to the expansion of space, always yields a constant background potential $-\tfrac{1}{2}c^{2}$. Analysis of this 'redshift' of the cosmic potential yields for perfect fluids the exact same solutions of the scale factor as the standard Friedmann equations, including an accelerating de Sitter universe. Though counter intuitive at first sight, gravity may drive cosmic acceleration. 
Herman Telkamp
physics.gen-ph