SIMBAD references

The nature of dark energy can be probed by the derivative Q={{dq}(z)/{dz}| }_{0} at redshift z=0 of the deceleration parameter q(z). It is probably static if Q\lt 1 or dynamic if Q\gt 2.5 , supporting ΛCDM or Λ=(1-q)
H^{2} , respectively, where H denotes the Hubble parameter. We derive q=1-{(4π{a}_{0}/{cH})}^{2} , enabling a determination of q(z) by measuring Milgrom's parameter, {a}_{0}(z) , in galaxy rotation curves, equivalent to the coefficient A in the Tully-Fisher relation {V}
_c{4}={{AM}}_\ between a rotation velocity V_ c_ and a baryonic mass M_ b_. We infer that dark matter should be extremely light, with clustering limited to the size of galaxy clusters. The associated transition radius to non-Newtonian gravity can conceivably be probed in a freefall Cavendish-type experiment in space.