Do Newton's G and Milgrom's a_0 vary with cosmological epoch ?

Understand

In the scalar tensor gravitational theories Newton's constant G_N evolves in the expanding universe.

• Likewise, it has been speculated that the acceleration scale a_0 in Milgrom's modified Newtonian dynamics (MOND) is tied to the scale of the cosmos, and must thus evolve.
• With the advent of relativistic implementations of the modified dynamics, one can address the issue of variability of the two gravitational ''constants'' with some confidence.
• Using TeVeS, the Tensor-Vector-Scalar gravitational theory, as an implementation of MOND, we calculate the dependence of G_N and a_0 on the TeVeS parameters and the coeval cosmological value of its scalar field, \phi_c.